[英]Control bound to property value doesn't update
I'm having a bit of a problem with WPF property binding. WPF属性绑定存在一些问题。 First the code. 首先是代码。
C# C#
public partial class WPFTextBox: UserControl
{
private bool _bold;
public bool Bold
{
get { return _bold; }
set
{
_bold = value;
OnPropertyChanged("Bold");
}
}
private bool _selectionChanged;
public WPFTextBox()
{
InitializeComponent();
DataContext = this;
Bold = true; // <--- This works, the checkbox will be checked
_selectionChanged = false;
}
private void txtDetails_SelectionChanged(object sender, RoutedEventArgs e)
{
var selection = txtDetails.Selection;
_selectionChanged = true;
Bold = selection.FontWeight() == FontWeights.Bold;
// ^-- This doesn't work It will trigger everything, but the checkbox won't
// change value. FontWeight() is an extension I wrote
_selectionChanged = false;
}
private void OnPropertyChanged(string name)
{
if(_selectionChanged)
return; // If the change was brought from the user moving the
// cursor in the textbox, don't change the textbox.
TextRange range = txtDetails.Selection;
switch(name)
{
case "Bold":
// change selection to bold, like I mentioned I does work
break;
default:
break;
}
}
}
XAML XAML
<RichTextBox Name="txtDetails" SelectionChanged="txtDetails_SelectionChanged"/>
<CheckBox Name="chkBold" Content="Bold" IsChecked="{Binding Path=Bold}"/>
I'm creating a textbox with format options. 我正在创建一个带有格式选项的文本框。 The binding works in the constructor, but not in the selection changed event. 绑定在构造函数中有效,但在选择更改事件中无效。 I've tried adding a lot of options to the binding such as Mode=TwoWay
and different property changed triggers. 我尝试将许多选项添加到绑定中,例如Mode=TwoWay
以及不同的属性更改触发器。
The reason I'm using the _selectionChanged
bool is because if I don't check for that, if I have a word was different formatting such as he llo and I click on it, it will change the formatting for all of the word to either bold or not. 我使用_selectionChanged
bool的原因是,如果我不检查它,如果我有一个单词是其他格式(例如helo) ,然后单击它,它将把所有单词的格式更改为是否大胆。 I think maybe it's because I'm handling it in selection changed event, but then I'm not sure where else I could change property value. 我认为可能是因为我在选择更改事件中处理它,但是我不确定我还能在其他地方更改属性值。
You need to inherit INotifyPropertyChanged
interface 您需要继承INotifyPropertyChanged
接口
and implement PropertyChangedEventHandler
并实现PropertyChangedEventHandler
public class WPFTextBox: UserControl,System.ComponentModel.INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
And call OnPropertyChanged
in the setter of your property 然后在属性的设置器中调用OnPropertyChanged
1.You can use UpdateSourceTrigger=PropertyChanged event also. 1.您也可以使用UpdateSourceTrigger = PropertyChanged事件。 2.Yes binding work on controls from the Extended WPF Toolkit. 2.是的,对扩展WPF工具包中的控件进行绑定工作。 IsChecked="{xcd:Path=Bold}" IsChecked =“ {xcd:Path = Bold}”
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