inotifypropertychanged

Why does OnPropertyChanged not work in Code Behind?

由 删除回忆录丶 提交于 2019-11-30 04:29:57
问题 I'm trying to simplify some code by putting the ViewModel models into the code behind and binding the DataContext as "this", but it seems to work differently, in the following example: Why is it when the button is clicked, the TextBlock bound to "Message" does not change, even though OnPropertyChanged("Message") is called? XAML: <Window x:Class="TestSimple223.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title

.NET WinForms INotifyPropertyChanged updates all bindings when one is changed. Better way?

由 帅比萌擦擦* 提交于 2019-11-30 02:03:38
In a windows forms application, a property change that triggers INotifyPropertyChanged, will result in the form reading EVERY property from my bound object, not just the property changed. (See example code below) This seems absurdly wasteful since the interface requires the name of the changing property. It is causing a lot of clocking in my app because some of the property getters require calculations to be performed. I'll likely need to implement some sort of logic in my getters to discard the unnecessary reads if there is no better way to do this. Am I missing something? Is there a better

How to get Getter backing field from PropertyInfo?

由 試著忘記壹切 提交于 2019-11-29 17:05:12
I have a class as follows: class Foo : PropertyChangedBase { private int _property; public int Property { get { return _property; } set { OnAssignPropertyChanged("Property", () => _property, value); } } PropertyChangedBase implements INotifyPropertyChanged with the following methods: protected void OnAssignmentPropertyChanged<T>(string propertyName, Expression<Func<T>> fieldExpression, T value) { var get = fieldExpression.Compile(); if (get().Equals(value)) { return; } // invoke set property method SetProperty(fieldExpression, value); PropertyChanged?.Invoke(this, new PropertyChangedEventArgs

INotifyPropertyChanged and static properties

由 ￣綄美尐妖づ 提交于 2019-11-29 16:46:28
问题 I'm tying myself in knots over a simple problem. I have a class that implements INotifyPropertyChanged . Some of the instance properties' getters use static properties and thus their values may change if the static property changes? Here's a simplified example. class ExampleClass : INotifyPropertyChanged { private static int _MinimumLength = 5; public static int MinimumLength { get { return _MinimumLength; } set { if (_MinimumLength != value) { _MinimumLength = value; //WHAT GOES HERE } } }

Create an event to watch for a change of variable

由 核能气质少年 提交于 2019-11-29 13:58:31
问题 Let's just say that I have: public Boolean booleanValue; public bool someMethod(string value) { // Do some work in here. return booleanValue = true; } How can I create an event handler that fires up when the booleanValue has changed? Is it possible? 回答1: Avoid using public fields as a rule in general. Try to keep them private as much as you can. Then, you can use a wrapper property firing your event. See the example: class Foo { Boolean _booleanValue; public bool BooleanValue { get { return

How to exclude nonserializable observers from a [Serializable] INotifyPropertyChanged implementor?

由 你。 提交于 2019-11-29 13:23:30
问题 I have almost a hundred of entity classes looking like that: [Serializable] public class SampleEntity : INotifyPropertyChanged { private string name; public string Name { get { return this.name; } set { this.name = value; FirePropertyChanged("Name"); } } [field:NonSerialized] public event PropertyChangedEventHandler PropertyChanged; private void FirePropertyChanged(string propertyName) { if (this.PropertyChanged != null) this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));

Get Deleted Item in ItemChanging event of BindingList

由 最后都变了- 提交于 2019-11-29 11:01:03
问题 I am using Binding List in my application along with ItemChanged event. Is there any way I could know the previous values of properties in ItemChanged event. Currently I am adding a separate property named 'OldValue' to achieve this. Is there any way to know about the deleted item in item changed event. I am not able to find any way to know which item has been deleted from the list. 回答1: If I understand correctly, you want to get info about item which was deleted from binding list. I think

Adding INotifyPropertyChanged to Model?

由 …衆ロ難τιáo~ 提交于 2019-11-29 10:35:40
I'm facing some design questions in my wpf MVVM (Prism based) application, would be happy to get your advice. My model is very simple: public class Customer { public string FirstName {get;set;} public string LastName {get;set;} } As you can see, I don't have any INotifyPropertyChnaged support for my Model class. I also have ViewModel for the CustomerDetails screen, that support INotifyPropertyChanged. public class CustomerDetailsViewModel:INotifyPropertyChanged /*Or NotificationObject*/ { /*INotifyPropertyChanged event */ private Customer item; public Customer Item { get{return item;} set {

ObservableDictionary for c#

由 余生颓废 提交于 2019-11-29 10:23:56
I'm trying to use following implementation of the ObservableDictionary: ObservableDictionary (C#) . When I'm using following code while binding the dictionary to a DataGrid: ObserveableDictionary<string,string> dd=new ObserveableDictionary<string,string>(); .... dd["aa"]="bb"; .... dd["aa"]="cc"; at dd["aa"]="cc"; I'm getting following exception Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index This exception is thrown in CollectionChanged(this, new NotifyCollectionChangedEventArgs(action, newItem, oldItem) in the following method:

ObservableCollection<T> in Winforms and possible alternatives

由 蓝咒 提交于 2019-11-29 08:39:10
Winforms .net 3.5 app. In my app I have a generic class that looks like so: public class FilterItem { public FilterItem() { } public string FilterProperty { get; set; } public bool FilterPropertyChecked { get; set; } public ComparitiveOperator FilterOperator { get; set; } public string FilterValue { get; set; } } and I use it in all of my dialog boxes when I want to implement some sort of filter functionality. So I call the dialog form with a pre-poulated List<FilterItem> passed in the constructor. Now when the dialog loads, it iterates thru each list-item and adds: A checkbox A combobox A
订阅 inotifypropertychanged