问题
If I call SelectAll from a GotFocus event handler, it doesn't work with the mouse - the selection disappears as soon as mouse is released.
EDIT: People are liking Donnelle's answer, I'll try to explain why I did not like it as much as the accepted answer.
- It is more complex, while the accepted answer does the same thing in a simpler way.
- The usability of accepted answer is better. When you click in the middle of the text, text gets unselected when you release the mouse allowing you to start editing instantly, and if you still want to select all, just press the button again and this time it will not unselect on release. Following Donelle's recipe, if I click in the middle of text, I have to click second time to be able to edit. If I click somewhere within the text versus outside of the text, this most probably means I want to start editing instead of overwriting everything.
回答1:
Don't know why it loses the selection in the GotFocus event.
But one solution is to do the selection on the GotKeyboardFocus and the GotMouseCapture events. That way it will always work.
回答2:
We have it so the first click selects all, and another click goes to cursor (our application is designed for use on tablets with pens).
You might find it useful.
public class ClickSelectTextBox : TextBox
{
public ClickSelectTextBox()
{
AddHandler(PreviewMouseLeftButtonDownEvent,
new MouseButtonEventHandler(SelectivelyIgnoreMouseButton), true);
AddHandler(GotKeyboardFocusEvent,
new RoutedEventHandler(SelectAllText), true);
AddHandler(MouseDoubleClickEvent,
new RoutedEventHandler(SelectAllText), true);
}
private static void SelectivelyIgnoreMouseButton(object sender,
MouseButtonEventArgs e)
{
// Find the TextBox
DependencyObject parent = e.OriginalSource as UIElement;
while (parent != null && !(parent is TextBox))
parent = VisualTreeHelper.GetParent(parent);
if (parent != null)
{
var textBox = (TextBox)parent;
if (!textBox.IsKeyboardFocusWithin)
{
// If the text box is not yet focussed, give it the focus and
// stop further processing of this click event.
textBox.Focus();
e.Handled = true;
}
}
}
private static void SelectAllText(object sender, RoutedEventArgs e)
{
var textBox = e.OriginalSource as TextBox;
if (textBox != null)
textBox.SelectAll();
}
}
回答3:
Donnelle's answer works the best, but having to derive a new class to use it is a pain.
Instead of doing that I register handlers the handlers in App.xaml.cs for all TextBoxes in the application. This allows me to use a Donnelle's answer with standard TextBox control.
Add the following methods to your App.xaml.cs:
public partial class App : Application
{
protected override void OnStartup(StartupEventArgs e)
{
// Select the text in a TextBox when it receives focus.
EventManager.RegisterClassHandler(typeof(TextBox), TextBox.PreviewMouseLeftButtonDownEvent,
new MouseButtonEventHandler(SelectivelyIgnoreMouseButton));
EventManager.RegisterClassHandler(typeof(TextBox), TextBox.GotKeyboardFocusEvent,
new RoutedEventHandler(SelectAllText));
EventManager.RegisterClassHandler(typeof(TextBox), TextBox.MouseDoubleClickEvent,
new RoutedEventHandler(SelectAllText));
base.OnStartup(e);
}
void SelectivelyIgnoreMouseButton(object sender, MouseButtonEventArgs e)
{
// Find the TextBox
DependencyObject parent = e.OriginalSource as UIElement;
while (parent != null && !(parent is TextBox))
parent = VisualTreeHelper.GetParent(parent);
if (parent != null)
{
var textBox = (TextBox)parent;
if (!textBox.IsKeyboardFocusWithin)
{
// If the text box is not yet focused, give it the focus and
// stop further processing of this click event.
textBox.Focus();
e.Handled = true;
}
}
}
void SelectAllText(object sender, RoutedEventArgs e)
{
var textBox = e.OriginalSource as TextBox;
if (textBox != null)
textBox.SelectAll();
}
}
回答4:
This is rather old, but I'll display my answer anyway.
I have chosen part of Donnelle's answer (skipped the double-click) for I think this creates the least astonishment in the users. However, like gcores I dislike the need to create a derived class. But I also don't like gcores "on Startup..." method. And I need this on a "generally but not always"-basis.
I have Implemented this as an attached dependency Property so I can set SelectTextOnFocus.Active=True in xaml. I find this way the most pleasing.
namespace foo.styles.behaviour
{
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
public class SelectTextOnFocus : DependencyObject
{
public static readonly DependencyProperty ActiveProperty = DependencyProperty.RegisterAttached(
"Active",
typeof(bool),
typeof(SelectTextOnFocus),
new PropertyMetadata(false, ActivePropertyChanged));
private static void ActivePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (d is TextBox)
{
TextBox textBox = d as TextBox;
if ((e.NewValue as bool?).GetValueOrDefault(false))
{
textBox.GotKeyboardFocus += OnKeyboardFocusSelectText;
textBox.PreviewMouseLeftButtonDown += OnMouseLeftButtonDown;
}
else
{
textBox.GotKeyboardFocus -= OnKeyboardFocusSelectText;
textBox.PreviewMouseLeftButtonDown -= OnMouseLeftButtonDown;
}
}
}
private static void OnMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
DependencyObject dependencyObject = GetParentFromVisualTree(e.OriginalSource);
if (dependencyObject == null)
{
return;
}
var textBox = (TextBox)dependencyObject;
if (!textBox.IsKeyboardFocusWithin)
{
textBox.Focus();
e.Handled = true;
}
}
private static DependencyObject GetParentFromVisualTree(object source)
{
DependencyObject parent = source as UIElement;
while (parent != null && !(parent is TextBox))
{
parent = VisualTreeHelper.GetParent(parent);
}
return parent;
}
private static void OnKeyboardFocusSelectText(object sender, KeyboardFocusChangedEventArgs e)
{
TextBox textBox = e.OriginalSource as TextBox;
if (textBox != null)
{
textBox.SelectAll();
}
}
[AttachedPropertyBrowsableForChildrenAttribute(IncludeDescendants = false)]
[AttachedPropertyBrowsableForType(typeof(TextBox))]
public static bool GetActive(DependencyObject @object)
{
return (bool) @object.GetValue(ActiveProperty);
}
public static void SetActive(DependencyObject @object, bool value)
{
@object.SetValue(ActiveProperty, value);
}
}
}
For my "general but not always"-feature I set this Property to True in a (global) TextBox-Style. This way "selecting the Text" is always "on", but I am able to disable it on a per-Textbox-basis.
回答5:
Here are the Blend behaviors implementing the answer solution for your convenience:
One for attaching to a single TextBox:
public class SelectAllTextOnFocusBehavior : Behavior<TextBox>
{
protected override void OnAttached()
{
base.OnAttached();
AssociatedObject.GotKeyboardFocus += AssociatedObjectGotKeyboardFocus;
AssociatedObject.GotMouseCapture += AssociatedObjectGotMouseCapture;
AssociatedObject.PreviewMouseLeftButtonDown += AssociatedObjectPreviewMouseLeftButtonDown;
}
protected override void OnDetaching()
{
base.OnDetaching();
AssociatedObject.GotKeyboardFocus -= AssociatedObjectGotKeyboardFocus;
AssociatedObject.GotMouseCapture -= AssociatedObjectGotMouseCapture;
AssociatedObject.PreviewMouseLeftButtonDown -= AssociatedObjectPreviewMouseLeftButtonDown;
}
private void AssociatedObjectGotKeyboardFocus(object sender,
System.Windows.Input.KeyboardFocusChangedEventArgs e)
{
AssociatedObject.SelectAll();
}
private void AssociatedObjectGotMouseCapture(object sender,
System.Windows.Input.MouseEventArgs e)
{
AssociatedObject.SelectAll();
}
private void AssociatedObjectPreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
if(!AssociatedObject.IsKeyboardFocusWithin)
{
AssociatedObject.Focus();
e.Handled = true;
}
}
}
And one for attaching to the root of a container containing multiple TextBox'es:
public class SelectAllTextOnFocusMultiBehavior : Behavior<UIElement>
{
protected override void OnAttached()
{
base.OnAttached();
AssociatedObject.GotKeyboardFocus += HandleKeyboardFocus;
AssociatedObject.GotMouseCapture += HandleMouseCapture;
}
protected override void OnDetaching()
{
base.OnDetaching();
AssociatedObject.GotKeyboardFocus -= HandleKeyboardFocus;
AssociatedObject.GotMouseCapture -= HandleMouseCapture;
}
private static void HandleKeyboardFocus(object sender,
System.Windows.Input.KeyboardFocusChangedEventArgs e)
{
var txt = e.NewFocus as TextBox;
if (txt != null)
txt.SelectAll();
}
private static void HandleMouseCapture(object sender,
System.Windows.Input.MouseEventArgs e)
{
var txt = e.OriginalSource as TextBox;
if (txt != null)
txt.SelectAll();
}
}
回答6:
Although this is an old question, I have just had this problem but solved it using an Attached Behavior, rather than an Expression Behavior as in Sergey's answer. This means I don't need a dependency on System.Windows.Interactivity in the Blend SDK:
public class TextBoxBehavior
{
public static bool GetSelectAllTextOnFocus(TextBox textBox)
{
return (bool)textBox.GetValue(SelectAllTextOnFocusProperty);
}
public static void SetSelectAllTextOnFocus(TextBox textBox, bool value)
{
textBox.SetValue(SelectAllTextOnFocusProperty, value);
}
public static readonly DependencyProperty SelectAllTextOnFocusProperty =
DependencyProperty.RegisterAttached(
"SelectAllTextOnFocus",
typeof (bool),
typeof (TextBoxBehavior),
new UIPropertyMetadata(false, OnSelectAllTextOnFocusChanged));
private static void OnSelectAllTextOnFocusChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var textBox = d as TextBox;
if (textBox == null) return;
if (e.NewValue is bool == false) return;
if ((bool) e.NewValue)
{
textBox.GotFocus += SelectAll;
textBox.PreviewMouseDown += IgnoreMouseButton;
}
else
{
textBox.GotFocus -= SelectAll;
textBox.PreviewMouseDown -= IgnoreMouseButton;
}
}
private static void SelectAll(object sender, RoutedEventArgs e)
{
var textBox = e.OriginalSource as TextBox;
if (textBox == null) return;
textBox.SelectAll();
}
private static void IgnoreMouseButton(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
var textBox = sender as TextBox;
if (textBox == null || (!textBox.IsReadOnly && textBox.IsKeyboardFocusWithin)) return;
e.Handled = true;
textBox.Focus();
}
}
You can then use it in your XAML like this:
<TextBox Text="Some Text" behaviors:TextBoxBehavior.SelectAllTextOnFocus="True"/>
I blogged about it here.
回答7:
Here's a very good very simple solution on MSDN:
<TextBox
MouseDoubleClick="SelectAddress"
GotKeyboardFocus="SelectAddress"
PreviewMouseLeftButtonDown="SelectivelyIgnoreMouseButton" />
Here's the code behind:
private void SelectAddress(object sender, RoutedEventArgs e)
{
TextBox tb = (sender as TextBox);
if (tb != null)
{
tb.SelectAll();
}
}
private void SelectivelyIgnoreMouseButton(object sender,
MouseButtonEventArgs e)
{
TextBox tb = (sender as TextBox);
if (tb != null)
{
if (!tb.IsKeyboardFocusWithin)
{
e.Handled = true;
tb.Focus();
}
}
}
回答8:
I think this works well:
private void ValueText_GotFocus(object sender, RoutedEventArgs e)
{
TextBox tb = (TextBox)e.OriginalSource;
tb.Dispatcher.BeginInvoke(
new Action(delegate
{
tb.SelectAll();
}), System.Windows.Threading.DispatcherPriority.Input);
}
If you would like to implement it as an extension method:
public static void SelectAllText(this System.Windows.Controls.TextBox tb)
{
tb.Dispatcher.BeginInvoke(
new Action(delegate
{
tb.SelectAll();
}), System.Windows.Threading.DispatcherPriority.Input);
}
And in your GotFocus event:
private void ValueText_GotFocus(object sender, RoutedEventArgs e)
{
TextBox tb = (TextBox)e.OriginalSource;
tb.SelectAllText();
}
I discovered the solution above because several months ago I was looking for a way to set focus to a given UIElement. I discovered the the code below somewhere (credit is hereby given) and it works well. I post it even though it is not directly related to the OP's question because it demonstrates the same pattern of using Dispatcher to work with a UIElement.
// Sets focus to uiElement
public static void DelayedFocus(this UIElement uiElement)
{
uiElement.Dispatcher.BeginInvoke(
new Action(delegate
{
uiElement.Focusable = true;
uiElement.Focus();
Keyboard.Focus(uiElement);
}),
DispatcherPriority.Render);
}
回答9:
I've found none of the answers presented here mimic a standard Windows textbox. For instance, try to click in the white space between the last character of the textbox and the right side of the textbox. Most of the solutions here will always select the whole content, which makes it very difficult to append text to a textbox.
The answer that I present here behaves better in this respect. It is a behavior (so it requires the System.Windows.Interactivity assembly from the Blend SDK). It could be rewritten using attached properties as well.
public sealed class SelectAllTextOnFocusBehavior : Behavior<TextBox>
{
protected override void OnAttached()
{
base.OnAttached();
AssociatedObject.PreviewMouseLeftButtonDown += AssociatedObject_PreviewMouseLeftButtonDown;
}
protected override void OnDetaching()
{
base.OnDetaching();
AssociatedObject.PreviewMouseLeftButtonDown -= AssociatedObject_PreviewMouseLeftButtonDown;
}
void AssociatedObject_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
// Find the textbox
DependencyObject parent = e.OriginalSource as UIElement;
while (parent != null && !(parent is TextBox))
parent = VisualTreeHelper.GetParent(parent);
var textBox = parent as TextBox;
Debug.Assert(textBox != null);
if (textBox.IsFocused) return;
textBox.SelectAll();
Keyboard.Focus(textBox);
e.Handled = true;
}
}
This is based on code I've found here.
回答10:
This simple implementation works perfectly for me:
void TextBox_GotFocus(object sender, RoutedEventArgs e)
{
((TextBox) sender).SelectAll();
}
void TextBox_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
var TextBox = (TextBox) sender;
if (!TextBox.IsKeyboardFocusWithin)
{
TextBox.Focus();
e.Handled = true;
}
}
To apply it to all TextBox's, put the following code after InitializeComponent();
EventManager.RegisterClassHandler(typeof(TextBox), TextBox.GotFocusEvent, new RoutedEventHandler(TextBox_GotFocus));
EventManager.RegisterClassHandler(typeof(TextBox), TextBox.PreviewMouseDownEvent, new MouseButtonEventHandler(TextBox_PreviewMouseDown));
回答11:
in App.xaml file
<Application.Resources>
<Style TargetType="TextBox">
<EventSetter Event="GotKeyboardFocus" Handler="TextBox_GotKeyboardFocus"/>
</Style>
</Application.Resources>
in App.xaml.cs file
private void TextBox_GotKeyboardFocus(Object sender, KeyboardFocusChangedEventArgs e)
{
((TextBox)sender).SelectAll();
}
With this code you reach all TextBox in your Application.
回答12:
Taken from here:
Register global event handler in App.xaml.cs file:
protected override void OnStartup(StartupEventArgs e)
{
EventManager.RegisterClassHandler(typeof(TextBox),TextBox.GotFocusEvent,
new RoutedEventHandler(TextBox_GotFocus));
base.OnStartup(e);
}
Then the handler is as simple as:
private void TextBox_GotFocus(object sender, RoutedEventArgs e)
{
(sender as TextBox).SelectAll();
}
回答13:
I have a slightly simplified answer for this (with just the PreviewMouseLeftButtonDown event) which seems to mimic the usual functionality of a browser:
In xaml you have a textbox say:
<TextBox Text="http://www.blabla.com" BorderThickness="2" BorderBrush="Green" VerticalAlignment="Center" Height="25"
PreviewMouseLeftButtonDown="SelectAll" />
In codebehind:
private void SelectAll(object sender, MouseButtonEventArgs e)
{
TextBox tb = (sender as TextBox);
if (tb == null)
{
return;
}
if (!tb.IsKeyboardFocusWithin)
{
tb.SelectAll();
e.Handled = true;
tb.Focus();
}
}
回答14:
Here is the C# version of the answer posted by @Nasenbaer
private delegate void TextBoxSelectAllDelegate(object sender);
private void TextBoxSelectAll(object sender)
{
(sender as System.Windows.Controls.TextBox).SelectAll();
}
private void MyTextBox_GotFocus(object sender, System.Windows.RoutedEventArgs e)
{
TextBoxSelectAllDelegate d = TextBoxSelectAll;
this.Dispatcher.BeginInvoke(d,
System.Windows.Threading.DispatcherPriority.ApplicationIdle, sender);
}
whereas MyTextBox_GotFocus is the event handler assigned to the GotFocus event of MyTextBox.
回答15:
I realize this is very old, but here is my solution which is based on the expressions/microsoft interactivity and interactions name spaces.
First, I followed the instructions at this link to place interactivity triggers into a style.
Then it comes down to this
<Style x:Key="baseTextBox" TargetType="TextBox">
<Setter Property="gint:InteractivityItems.Template">
<Setter.Value>
<gint:InteractivityTemplate>
<gint:InteractivityItems>
<gint:InteractivityItems.Triggers>
<i:EventTrigger EventName="GotKeyboardFocus">
<ei:CallMethodAction MethodName="SelectAll"/>
</i:EventTrigger>
<i:EventTrigger EventName="PreviewMouseLeftButtonDown">
<ei:CallMethodAction MethodName="TextBox_PreviewMouseLeftButtonDown"
TargetObject="{Binding ElementName=HostElementName}"/>
</i:EventTrigger>
</gint:InteractivityItems.Triggers>
</gint:InteractivityItems>
</gint:InteractivityTemplate>
</Setter.Value>
</Setter>
</Style>
and this
public void TextBox_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
TextBox tb = e.Source as TextBox;
if((tb != null) && (tb.IsKeyboardFocusWithin == false))
{
tb.Focus();
e.Handled = true;
}
}
In my case, I have a user control where the text boxes are that has a code-behind. The code-behind has the handler function. I gave my user control a name in xaml, and I am using that name for the element. This is working perfectly for me. Simply apply the style to any textbox where you would like to have all the text selected when you click in the textbox.
The first CallMethodAction calls the text box's SelectAll function when the GotKeyboardFocus event on the textbox fires.
I hope this helps.
回答16:
For those interested in Donnelle's/Groky's approach, but want a click to the right of the last character (but still within the TextBox) to place the caret at the end of the entered text, I've come up with this solution:
int GetRoundedCharacterIndexFromPoint(TextBox textBox, Point clickedPoint)
{
int position = textBox.GetCharacterIndexFromPoint(clickedPoint, true);
// Check if the clicked point is actually closer to the next character
// or if it exceeds the righmost character in the textbox
// (in this case return increase the position by 1)
Rect charLeftEdge = textBox.GetRectFromCharacterIndex(position, false);
Rect charRightEdge = textBox.GetRectFromCharacterIndex(position, true);
double charWidth = charRightEdge.X - charLeftEdge.X;
if (clickedPoint.X + charWidth / 2 > charLeftEdge.X + charWidth) position++;
return position;
}
void SelectivelyIgnoreMouseButton(object sender, MouseButtonEventArgs e)
{
// Find the TextBox
DependencyObject parent = e.OriginalSource as UIElement;
while (parent != null && !(parent is TextBox))
parent = VisualTreeHelper.GetParent(parent);
if (parent != null)
{
var textBox = (TextBox)parent;
if (!textBox.IsKeyboardFocusWithin)
{
// If the text box is not yet focused, give it the focus and
// stop further processing of this click event.
textBox.Focus();
e.Handled = true;
}
else
{
int pos = GetRoundedCharacterIndexFromPoint(textBox, e.GetPosition(textBox));
textBox.CaretIndex = pos;
}
}
}
void SelectAllText(object sender, RoutedEventArgs e)
{
var textBox = e.OriginalSource as TextBox;
if (textBox != null)
textBox.SelectAll();
}
The GetRoundedCharacterIndexFromPoint method was taken from this post.
回答17:
#region TextBoxIDCard selection
private bool textBoxIDCardGotFocus = false;
private void TextBoxIDCard_GotFocus(object sender, RoutedEventArgs e)
{
this.TextBoxIDCard.SelectAll();
}
private void TextBoxIDCard_LostFocus(object sender, RoutedEventArgs e)
{
textBoxIDCardGotFocus = false;
}
private void TextBoxIDCard_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
if (textBoxIDCardGotFocus == false)
{
e.Handled = true;
this.TextBoxIDCard.Focus();
textBoxIDCardGotFocus = true;
}
}
#endregion
回答18:
Try this extension method to add the desired behaviour to any TextBox control. I havn't tested it extensively yet, but it seems to fulfil my needs.
public static class TextBoxExtensions
{
public static void SetupSelectAllOnGotFocus(this TextBox source)
{
source.GotFocus += SelectAll;
source.PreviewMouseLeftButtonDown += SelectivelyIgnoreMouseButton;
}
private static void SelectAll(object sender, RoutedEventArgs e)
{
var textBox = e.OriginalSource as TextBox;
if (textBox != null)
textBox.SelectAll();
}
private static void SelectivelyIgnoreMouseButton(object sender, MouseButtonEventArgs e)
{
var textBox = (sender as TextBox);
if (textBox != null)
{
if (!textBox.IsKeyboardFocusWithin)
{
e.Handled = true;
textBox.Focus();
}
}
}
}
回答19:
I searched a lot for the solution, I found couple of solutions to selectall But, the issue is when we do right click and do cut/copy after selecting part of text from text box, it selects all even I selected part of text. To fix this here is the solution. Just add the below code in the keyboard select event. This worked for me.
private static void SelectContentsChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (d is TextBox)
{
TextBox textBox = d as TextBox;
if ((e.NewValue as bool?).GetValueOrDefault(false))
{
textBox.GotKeyboardFocus += OnKeyboardFocusSelectText;
}
else
{
textBox.GotKeyboardFocus -= OnKeyboardFocusSelectText;
}
}
}
private static void OnKeyboardFocusSelectText(object sender, KeyboardFocusChangedEventArgs e)
{
if (e.KeyboardDevice.IsKeyDown(Key.Tab))
((TextBox)sender).SelectAll();
}
回答20:
I have used Nils' answer but converted to more flexible.
public enum SelectAllMode
{
/// <summary>
/// On first focus, it selects all then leave off textbox and doesn't check again
/// </summary>
OnFirstFocusThenLeaveOff = 0,
/// <summary>
/// On first focus, it selects all then never selects
/// </summary>
OnFirstFocusThenNever = 1,
/// <summary>
/// Selects all on every focus
/// </summary>
OnEveryFocus = 2,
/// <summary>
/// Never selects text (WPF's default attitude)
/// </summary>
Never = 4,
}
public partial class TextBox : DependencyObject
{
public static readonly DependencyProperty SelectAllModeProperty = DependencyProperty.RegisterAttached(
"SelectAllMode",
typeof(SelectAllMode?),
typeof(TextBox),
new PropertyMetadata(SelectAllModePropertyChanged));
private static void SelectAllModePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (d is System.Windows.Controls.TextBox)
{
var textBox = d as System.Windows.Controls.TextBox;
if (e.NewValue != null)
{
textBox.GotKeyboardFocus += OnKeyboardFocusSelectText;
textBox.PreviewMouseLeftButtonDown += OnMouseLeftButtonDown;
}
else
{
textBox.GotKeyboardFocus -= OnKeyboardFocusSelectText;
textBox.PreviewMouseLeftButtonDown -= OnMouseLeftButtonDown;
}
}
}
private static void OnMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
DependencyObject dependencyObject = GetParentFromVisualTree(e.OriginalSource);
if (dependencyObject == null)
return;
var textBox = (System.Windows.Controls.TextBox)dependencyObject;
if (!textBox.IsKeyboardFocusWithin)
{
textBox.Focus();
e.Handled = true;
}
}
private static DependencyObject GetParentFromVisualTree(object source)
{
DependencyObject parent = source as UIElement;
while (parent != null && !(parent is System.Windows.Controls.TextBox))
{
parent = VisualTreeHelper.GetParent(parent);
}
return parent;
}
private static void OnKeyboardFocusSelectText(object sender, KeyboardFocusChangedEventArgs e)
{
var textBox = e.OriginalSource as System.Windows.Controls.TextBox;
if (textBox == null) return;
var selectAllMode = GetSelectAllMode(textBox);
if (selectAllMode == SelectAllMode.Never)
{
textBox.SelectionStart = 0;
textBox.SelectionLength = 0;
}
else
textBox.SelectAll();
if (selectAllMode == SelectAllMode.OnFirstFocusThenNever)
SetSelectAllMode(textBox, SelectAllMode.Never);
else if (selectAllMode == SelectAllMode.OnFirstFocusThenLeaveOff)
SetSelectAllMode(textBox, null);
}
[AttachedPropertyBrowsableForChildrenAttribute(IncludeDescendants = false)]
[AttachedPropertyBrowsableForType(typeof(System.Windows.Controls.TextBox))]
public static SelectAllMode? GetSelectAllMode(DependencyObject @object)
{
return (SelectAllMode)@object.GetValue(SelectAllModeProperty);
}
public static void SetSelectAllMode(DependencyObject @object, SelectAllMode? value)
{
@object.SetValue(SelectAllModeProperty, value);
}
}
In XAML, you can use like one of these:
<!-- On first focus, it selects all then leave off textbox and doesn't check again -->
<TextBox attprop:TextBox.SelectAllMode="OnFirstFocusThenLeaveOff" />
<!-- On first focus, it selects all then never selects -->
<TextBox attprop:TextBox.SelectAllMode="OnFirstFocusThenNever" />
<!-- Selects all on every focus -->
<TextBox attprop:TextBox.SelectAllMode="OnEveryFocus" />
<!-- Never selects text (WPF's default attitude) -->
<TextBox attprop:TextBox.SelectAllMode="Never" />
回答21:
I had same problem. In VB.Net it works easy that way:
VB XAML:
<TextBox x:Name="txtFilterFrequency" />
Codehind:
Private Sub txtFilterText_GotFocus(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles txtFilterText.GotFocus
Me.Dispatcher.BeginInvoke(Sub()
txtFilterText.SelectAll()
End Sub, DispatcherPriority.ApplicationIdle, Nothing)
End Sub
C# (thanks to ViRuSTriNiTy)
private delegate void TextBoxSelectAllDelegate(object sender);
private void TextBoxSelectAll(object sender)
{
(sender as System.Windows.Controls.TextBox).SelectAll();
}
private void MyTextBox_GotFocus(object sender, System.Windows.RoutedEventArgs e)
{
TextBoxSelectAllDelegate d = TextBoxSelectAll;
this.Dispatcher.BeginInvoke(d,
System.Windows.Threading.DispatcherPriority.ApplicationIdle, sender);
}
回答22:
This is by far the simplest solution.
Add a global handler to the application (App.xaml.cs) and done. You are going to need only a few lines of code.
protected override void OnStartup(StartupEventArgs e)
{
EventManager.RegisterClassHandler(typeof(TextBox),
TextBox.GotFocusEvent,
new RoutedEventHandler(TextBox_GotFocus));
base.OnStartup(e);
}
So use the EventManager class to register a global event handler against a type (TextBox). The actual handler is dead simple:
private void TextBox_GotFocus(object sender, RoutedEventArgs e)
{
(sender as TextBox).SelectAll();
}
Check here: WPF TextBox SelectAll on Focus
Hope it helps.
回答23:
This seems to work well for me. It's basically a recap of some earlier posts. I just put this into my MainWindow.xaml.cs file in the constructor. I create two handlers, one for keyboard, and one for the mouse, and funnel both events into the same function, HandleGotFocusEvent, which is defined right after the constructor in the same file.
public MainWindow()
{
InitializeComponent();
EventManager.RegisterClassHandler(typeof(TextBox),
UIElement.GotKeyboardFocusEvent,
new RoutedEventHandler(HandleGotFocusEvent), true);
EventManager.RegisterClassHandler(typeof(TextBox),
UIElement.GotMouseCaptureEvent,
new RoutedEventHandler(HandleGotFocusEvent), true);
}
private void HandleGotFocusEvent(object sender, RoutedEventArgs e)
{
if (sender is TextBox)
(sender as TextBox).SelectAll();
}
回答24:
An easy way to override the mouseDown and select all after doubleclick is:
public class DoubleClickTextBox: TextBox
{
public override void EndInit()
{
base.EndInit();
}
protected override void OnMouseEnter(System.Windows.Input.MouseEventArgs e)
{
base.OnMouseEnter(e);
this.Cursor = Cursors.Arrow;
}
protected override void OnMouseDown(System.Windows.Input.MouseButtonEventArgs e)
{
}
protected override void OnMouseDoubleClick(System.Windows.Input.MouseButtonEventArgs e)
{
base.OnMouseDown(e);
this.SelectAll();
}
}
回答25:
Try putting this in the constructor of whatever control is housing your textbox:
Loaded += (sender, e) =>
{
MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
myTextBox.SelectAll();
}
回答26:
Sergei.
After googling and testing, I've found a simple solution that worked for me.
You need to add an event handler to the "Loaded" event of your container window:
private void yourwindow_Loaded(object sender, RoutedEventArgs e)
{
EventManager.RegisterClassHandler(typeof(TextBox),
TextBox.PreviewMouseLeftButtonDownEvent,
new RoutedEventHandler(SelectivelyIgnoreMouseButton));
}
Next, you have to create the handler to the referenced RoutedEventHandler in previous code:
private void SelectivelyIgnoreMouseButton(object sender, RoutedEventArgs e)
{
TextBox tb = (sender as TextBox);
if (tb != null)
{
if (!tb.IsKeyboardFocusWithin)
{
e.Handled = true;
tb.Focus();
}
}
}
Now, you can add the SelectAll() command on GotFocus event handlers to any TextBox controls separately:
private void myTextBox_GotFocus(object sender, RoutedEventArgs e)
{
(sender as TextBox).SelectAll();
}
Your text now is selected on focus!
Adapted from Dr. WPF solution, MSDN Forums
回答27:
I have tested all of them but only the following worked out:
protected override void OnStartup(StartupEventArgs e)
{
EventManager.RegisterClassHandler(typeof(TextBox), UIElement.PreviewMouseLeftButtonDownEvent,
new MouseButtonEventHandler(SelectivelyHandleMouseButton), true);
EventManager.RegisterClassHandler(typeof(TextBox), UIElement.GotKeyboardFocusEvent,
new RoutedEventHandler(SelectAllText), true);
EventManager.RegisterClassHandler(typeof(TextBox), UIElement.GotFocusEvent,
new RoutedEventHandler(GotFocus), true);
}
private static void SelectivelyHandleMouseButton(object sender, MouseButtonEventArgs e)
{
var textbox = (sender as TextBox);
if (textbox != null)
{
int hc = textbox.GetHashCode();
if (hc == LastHashCode)
{
if (e.OriginalSource.GetType().Name == "TextBoxView")
{
e.Handled = true;
textbox.Focus();
LastHashCode = -1;
}
}
}
if (textbox != null) textbox.Focus();
}
private static void SelectAllText(object sender, RoutedEventArgs e)
{
var textBox = e.OriginalSource as TextBox;
if (textBox != null)
textBox.SelectAll();
}
private static int LastHashCode;
private static void GotFocus(object sender, RoutedEventArgs e)
{
var textBox = e.OriginalSource as TextBox;
if (textBox != null)
LastHashCode = textBox.GetHashCode();
}
回答28:
WOW! After reading all the above I find myself overwhelmed and confused. I took what I thought I learned in this post and tried something completely different. To select the text in a textbox when it gets focus I use this:
private void TextField_GotFocus(object sender, RoutedEventArgs e)
{
TextBox tb = (sender as Textbox);
if(tb != null)
{
e.Handled = true;
tb.Focus();
tb.SelectAll();
}
}
Set the GotFocus property of the textbox to this method.
Running the application and clicking once in the textbox highlights everything already in the textbox.
If indeed, the objective is to select the text when the user clicks in the textbox, this seems simple and involves a whole lot less code. Just saying...
来源：https://stackoverflow.com/questions/660554/how-to-automatically-select-all-text-on-focus-in-wpf-textbox