xaml

问题 Using XAML preferably, I need to dynamically apply a gray-scale filter on a colored image from bottom to top. That's to say, i would like to be able to change the offset value of the gray-scale filter applied to my image pro grammatically. For example, I would like to programmatically set 50% of the image in color (from the bottom of the image to its middle), and the other 50% of the image in gray-scale (e.g. from the middle of the image to its top). I have read a lot of different answers,

问题 I have a ScrollView over AbsoluteLayout .. I need to Fix the postion of the ActivityIndicator in centre of screen. I tried following code. <ScrollView> <AbsoluteLayout VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand"> <StackLayout BackgroundColor="White" Padding="50,20,50,20" Spacing="5" AbsoluteLayout.LayoutBounds="0,0,1,1" AbsoluteLayout.LayoutFlags="All"> // have set of elements.. </StackLayout> <ActivityIndicator IsVisible="{Binding IsBusy}" IsRunning="{Binding IsBusy}"

问题 I'm trying to debug a strange error in a combobox bound to an itemssource and selecteditem. It's driving me crazy. The problem arise when changing selected tabitem in which the combobox exists. (Actually it's only when changing the DataContext of the ComboBox). The SelectedItem-binding has a custom validationrule to give error if value is null. The problem is that wpf calls my custom rule when switching tabitems (DataContext) and tries to validate a value of null, even though the selecteditem

问题 I want to add some label and image above tabbed page in xamarin forms, so when i slide to another tabbed page the content above tabbed page will remain the same here is the design can i achieve this because i cant find any reference to do that ? 回答1: You can not add label above in tabbed page if you want to add label above tabbed page you have to crate your own tabbed page. You can create a layout that show/hide based on your selection for your selection create tab design and tap gesture to

问题 I'm having a simple WPF XAML Window, I need to Create a StaticResource Key with in the following XAML. The XAML Source Code is <Window x:Class="WpfApplication1.Trigger" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:super="clr-namespace:WpfApplication1" Title="Trigger" Height="300" Width="300"> <Grid> <Border x:Name="m_Border" Width="100" Height="30" HorizontalAlignment="Center" VerticalAlignment="Top" Background=

问题 I'm having a simple WPF XAML Window, I need to Create a StaticResource Key with in the following XAML. The XAML Source Code is <Window x:Class="WpfApplication1.Trigger" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:super="clr-namespace:WpfApplication1" Title="Trigger" Height="300" Width="300"> <Grid> <Border x:Name="m_Border" Width="100" Height="30" HorizontalAlignment="Center" VerticalAlignment="Top" Background=

问题 I've a Text box KeyUp Event Trigger Wired up to a command in WPF. I need to pass the actual key that was pressed as a command parameter. The command executes fine, but the code that handles it needs to know the actual key that was pressed (remember this could be an enter key or anything not just a letter, so I can't get it from the TextBox.text). Can't figure out how to do this. XAML: xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity" XAML: <TextBox

问题 Here I have defined my data myListOfEmployeeObjects : public class App : Application { public List<Employee> myListOfEmployeeObjects; public App () { Employee emp1 = new Employee () { FirstName = "Max", LastName = "Mustermann", Twitter = "@fake1" }; Employee emp2 = new Employee () { FirstName = "Evy", LastName = "Mustermann", Twitter = "@fake2" }; myListOfEmployeeObjects = new List<Employee> { emp1, emp2 }; MainPage = new NavigationPage (new EmployeeListPage ()); } } Than I have my XAML where

问题 Here I have defined my data myListOfEmployeeObjects : public class App : Application { public List<Employee> myListOfEmployeeObjects; public App () { Employee emp1 = new Employee () { FirstName = "Max", LastName = "Mustermann", Twitter = "@fake1" }; Employee emp2 = new Employee () { FirstName = "Evy", LastName = "Mustermann", Twitter = "@fake2" }; myListOfEmployeeObjects = new List<Employee> { emp1, emp2 }; MainPage = new NavigationPage (new EmployeeListPage ()); } } Than I have my XAML where

问题 When I iterate over a bunch of different controls on a Form, instead of trying to access the Text property: String text = String.Empty; foreach(Control control in this.Controls) { try { text = control.Text; } catch(Exception exception) { // This control probably doesn't have the Text property. Debug.WriteLine(exception.Message); } } Is there a way to just determine whether or not a given control has a Text property? Something like this: String text = String.Empty; foreach(Control control in