在后面的自定义控件代码中处理事件
Handle Events in Custom Control Code Behind
好吧,这可能是一个非常愚蠢的问题,但我已经搜索了很长时间,但找不到有效的解决方案...
我有一个继承自 Control
的自定义控件,其中应包含自动化代码。
例如 select 控件 TextBox
的所有文本 selected 时,或者当 TextBox
的内容更改时生成接近匹配列表。
public class vokDataGridEdit : Control
{
static vokDataGridEdit()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(vokDataGridEdit), new FrameworkPropertyMetadata(typeof(vokDataGridEdit)));
// Events internal to control (??? found on some how-to's)
EventManager.RegisterClassHandler(typeof(vokDataGridEdit), UIElement.GotKeyboardFocusEvent, new RoutedEventHandler(OnSelectContent), true);
}
// Dependecy Properties ...
// The Event that shall Fire when the TextBox gets Focus / Editing Mode
public static void SelectContent(object sender, RoutedEventArgs e)
{
if (sender is TextBox tb)
{
tb.SelectAll();
}
}
}
以及控件样式模板:
<ResourceDictionary xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x = "http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:ccont = "clr-namespace:App.Controls">
<!-- Default style for the Validation Buttons -->
<Style TargetType="{x:Type ccont:vokDataGridEdit}">
<Setter Property="SnapsToDevicePixels" Value="true" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ccont:vokDataGridEdit}">
<TextBox Text = "{Binding Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, RelativeSource={RelativeSource AncestorType=ccont:vokDataGridEdit}}"
BorderThickness = "0"
ContextMenuService.Placement = "Right"
ContextMenuService.PlacementTarget = "{Binding Path=., RelativeSource={RelativeSource Self}}"
GotKeyboardFocus = "SelectContent">
<TextBox.ContextMenu>
<ContextMenu>
<ContextMenu.Template>
<ControlTemplate>
<Border CornerRadius = "5"
Background = "LightGray"
BorderThickness = "1"
BorderBrush = "Gray"
Padding = "2">
<StackPanel Orientation="Vertical">
<!-- Title -->
<TextBlock Text="Test" />
<!-- TODO: List of matches -->
<TextBox Text = "{Binding Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, RelativeSource={RelativeSource AncestorType=ccont:vokDataGridEdit}}"
BorderThickness = "0" />
</StackPanel>
</Border>
</ControlTemplate>
</ContextMenu.Template>
</ContextMenu>
</TextBox.ContextMenu>
</TextBox>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
问题 1: 如何绑定事件 SelectContent
(到 select 所有 TextBox
内容,当它获得焦点时,nb:它是 DataGrid
的一部分 CellEditingTemplate
) 到 GotKeyboardFocus
?事件在 Apps 代码中正常,但对于自定义控件,它们不起作用,因为没有 "Code Behind" 真正用于样式...
问题 2: 假设我有一个包含单词数组的依赖项 属性。基于TextBox
的内容,我想select从Dependency属性中的Array中提取几个词,并将它们传递给Custom Control中的ListBox
( ListBox
的内容只能由自定义控件管理,而不是由任何使用该控件的人管理。是否有关于如何实现它的 prefered/canonical MVVM 架构?
通常你应该post只做一个问题,而不是多个问题。关于第一个,您可以使用 EventSetter
例如在 UserControl
的资源中隐式 Style
:
<Style TargetType="TextBox">
<EventSetter Event="GotKeyboardFocus" Handler="SelectContent"/>
</Style>
关于第二个问题 - 实施 属性,它是您列表的子集,并相应地更新它,例如如果依赖项 属性 已更改(请参阅 属性 已更改的回调)或子集所依赖的其他一些值已更改。
或者,您可以使用 TextBox
的行为并在那里处理您需要的事件。参见例如select 所有行为:
public class SelectAllBehavior : Behavior<TextBox>
{
private bool _doSelectAll = false;
protected override void OnAttached()
{
base.OnAttached();
AssociatedObject.GotFocus += AssociatedObject_GotFocus;
AssociatedObject.PreviewMouseUp += AssociatedObject_MouseUp;
AssociatedObject.PreviewMouseDown += AssociatedObject_MouseDown;
}
private void AssociatedObject_MouseUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
if (_doSelectAll)
{
AssociatedObject.Dispatcher.BeginInvoke((Action) (()=>{ AssociatedObject.SelectAll(); }));
}
_doSelectAll = false;
}
private void AssociatedObject_MouseDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
_doSelectAll = !AssociatedObject.IsFocused;
}
private void AssociatedObject_GotFocus(object sender, System.Windows.RoutedEventArgs e)
{
AssociatedObject.SelectAll();
}
protected override void OnDetaching()
{
AssociatedObject.GotFocus -= AssociatedObject_GotFocus;
AssociatedObject.PreviewMouseUp -= AssociatedObject_MouseUp;
AssociatedObject.PreviewMouseDown -= AssociatedObject_MouseDown;
base.OnDetaching();
}
}
在 XAML 中使用此行为:
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
<TextBox Text="Some text">
<i:Interaction.Behaviors>
<local:SelectAllBehavior/>
</i:Interaction.Behaviors>
</TextBox>
部分解:
我终于让直接控件上的事件起作用了(ContextMenu
中的控件仍然没有 EventHandlers...)。
显然,重点是使用 GetTemplateChild()
以按名称获取 TextBox,然后关联事件处理程序:
<ResourceDictionary xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x = "http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:ccont = "clr-namespace:App.Controls">
<!-- Default style for the Validation Buttons -->
<Style TargetType="{x:Type ccont:vokDataGridEdit}">
<Setter Property="SnapsToDevicePixels" Value="true" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ccont:vokDataGridEdit}">
<TextBox Text = "{Binding Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, RelativeSource={RelativeSource AncestorType=ccont:vokDataGridEdit}}"
BorderThickness = "0"
ContextMenuService.Placement = "Right"
ContextMenuService.PlacementTarget = "{Binding Path=., RelativeSource={RelativeSource Self}}"
x:Name = "TextBox">
<TextBox.ContextMenu>
<ContextMenu x:Name="Menu">
<ContextMenu.Template>
<ControlTemplate>
<Border CornerRadius = "5"
Background = "LightGray"
BorderThickness = "1"
BorderBrush = "Gray"
Padding = "2">
<StackPanel Orientation="Vertical">
<!-- Title -->
<TextBlock Text="Test" x:Name = "Test" />
<!-- TODO: List of matches -->
<TextBox Text = "{Binding Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, RelativeSource={RelativeSource AncestorType=ccont:vokDataGridEdit}}"
BorderThickness = "0" />
</StackPanel>
</Border>
</ControlTemplate>
</ContextMenu.Template>
</ContextMenu>
</TextBox.ContextMenu>
</TextBox>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
和代码(未显示依赖属性):
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
namespace App.Controls
{
/// <summary>
/// DataGrid Edit control (see: https://www.c-sharpcorner.com/article/wpf-routed-events/ for RoutedEvents)
/// </summary>
public class vokDataGridEdit : Control
{
static vokDataGridEdit()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(vokDataGridEdit), new FrameworkPropertyMetadata(typeof(vokDataGridEdit)));
}
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
// Demo purpose only, check for previous instances and remove the handler first
if (this.GetTemplateChild("TextBox") is TextBox button)
{
button.PreviewMouseLeftButtonDown += this.SelectContentPreparation;
button.GotKeyboardFocus += this.SelectContent;
button.MouseDoubleClick += this.SelectContent;
//button.GotFocus += this.SelectContent;
}
}
/// <summary>
/// Prepare the Control to ensure it has focus before subsequent event fire
/// </summary>
private void SelectContentPreparation(object sender, MouseButtonEventArgs e)
{
if (sender is TextBox tb)
{
if (!tb.IsKeyboardFocusWithin)
{
e.Handled = true;
tb.Focus();
}
}
}
private void SelectContent(object sender, RoutedEventArgs e)
{
if (sender is TextBox tb)
{
e.Handled = true;
tb.SelectAll();
}
}
}
}
好吧,这可能是一个非常愚蠢的问题,但我已经搜索了很长时间,但找不到有效的解决方案...
我有一个继承自 Control
的自定义控件,其中应包含自动化代码。
例如 select 控件 TextBox
的所有文本 selected 时,或者当 TextBox
的内容更改时生成接近匹配列表。
public class vokDataGridEdit : Control
{
static vokDataGridEdit()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(vokDataGridEdit), new FrameworkPropertyMetadata(typeof(vokDataGridEdit)));
// Events internal to control (??? found on some how-to's)
EventManager.RegisterClassHandler(typeof(vokDataGridEdit), UIElement.GotKeyboardFocusEvent, new RoutedEventHandler(OnSelectContent), true);
}
// Dependecy Properties ...
// The Event that shall Fire when the TextBox gets Focus / Editing Mode
public static void SelectContent(object sender, RoutedEventArgs e)
{
if (sender is TextBox tb)
{
tb.SelectAll();
}
}
}
以及控件样式模板:
<ResourceDictionary xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x = "http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:ccont = "clr-namespace:App.Controls">
<!-- Default style for the Validation Buttons -->
<Style TargetType="{x:Type ccont:vokDataGridEdit}">
<Setter Property="SnapsToDevicePixels" Value="true" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ccont:vokDataGridEdit}">
<TextBox Text = "{Binding Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, RelativeSource={RelativeSource AncestorType=ccont:vokDataGridEdit}}"
BorderThickness = "0"
ContextMenuService.Placement = "Right"
ContextMenuService.PlacementTarget = "{Binding Path=., RelativeSource={RelativeSource Self}}"
GotKeyboardFocus = "SelectContent">
<TextBox.ContextMenu>
<ContextMenu>
<ContextMenu.Template>
<ControlTemplate>
<Border CornerRadius = "5"
Background = "LightGray"
BorderThickness = "1"
BorderBrush = "Gray"
Padding = "2">
<StackPanel Orientation="Vertical">
<!-- Title -->
<TextBlock Text="Test" />
<!-- TODO: List of matches -->
<TextBox Text = "{Binding Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, RelativeSource={RelativeSource AncestorType=ccont:vokDataGridEdit}}"
BorderThickness = "0" />
</StackPanel>
</Border>
</ControlTemplate>
</ContextMenu.Template>
</ContextMenu>
</TextBox.ContextMenu>
</TextBox>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
问题 1: 如何绑定事件 SelectContent
(到 select 所有 TextBox
内容,当它获得焦点时,nb:它是 DataGrid
的一部分 CellEditingTemplate
) 到 GotKeyboardFocus
?事件在 Apps 代码中正常,但对于自定义控件,它们不起作用,因为没有 "Code Behind" 真正用于样式...
问题 2: 假设我有一个包含单词数组的依赖项 属性。基于TextBox
的内容,我想select从Dependency属性中的Array中提取几个词,并将它们传递给Custom Control中的ListBox
( ListBox
的内容只能由自定义控件管理,而不是由任何使用该控件的人管理。是否有关于如何实现它的 prefered/canonical MVVM 架构?
通常你应该post只做一个问题,而不是多个问题。关于第一个,您可以使用 EventSetter
例如在 UserControl
的资源中隐式 Style
:
<Style TargetType="TextBox">
<EventSetter Event="GotKeyboardFocus" Handler="SelectContent"/>
</Style>
关于第二个问题 - 实施 属性,它是您列表的子集,并相应地更新它,例如如果依赖项 属性 已更改(请参阅 属性 已更改的回调)或子集所依赖的其他一些值已更改。
或者,您可以使用 TextBox
的行为并在那里处理您需要的事件。参见例如select 所有行为:
public class SelectAllBehavior : Behavior<TextBox>
{
private bool _doSelectAll = false;
protected override void OnAttached()
{
base.OnAttached();
AssociatedObject.GotFocus += AssociatedObject_GotFocus;
AssociatedObject.PreviewMouseUp += AssociatedObject_MouseUp;
AssociatedObject.PreviewMouseDown += AssociatedObject_MouseDown;
}
private void AssociatedObject_MouseUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
if (_doSelectAll)
{
AssociatedObject.Dispatcher.BeginInvoke((Action) (()=>{ AssociatedObject.SelectAll(); }));
}
_doSelectAll = false;
}
private void AssociatedObject_MouseDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
_doSelectAll = !AssociatedObject.IsFocused;
}
private void AssociatedObject_GotFocus(object sender, System.Windows.RoutedEventArgs e)
{
AssociatedObject.SelectAll();
}
protected override void OnDetaching()
{
AssociatedObject.GotFocus -= AssociatedObject_GotFocus;
AssociatedObject.PreviewMouseUp -= AssociatedObject_MouseUp;
AssociatedObject.PreviewMouseDown -= AssociatedObject_MouseDown;
base.OnDetaching();
}
}
在 XAML 中使用此行为:
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
<TextBox Text="Some text">
<i:Interaction.Behaviors>
<local:SelectAllBehavior/>
</i:Interaction.Behaviors>
</TextBox>
部分解:
我终于让直接控件上的事件起作用了(ContextMenu
中的控件仍然没有 EventHandlers...)。
显然,重点是使用 GetTemplateChild()
以按名称获取 TextBox,然后关联事件处理程序:
<ResourceDictionary xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x = "http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:ccont = "clr-namespace:App.Controls">
<!-- Default style for the Validation Buttons -->
<Style TargetType="{x:Type ccont:vokDataGridEdit}">
<Setter Property="SnapsToDevicePixels" Value="true" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ccont:vokDataGridEdit}">
<TextBox Text = "{Binding Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, RelativeSource={RelativeSource AncestorType=ccont:vokDataGridEdit}}"
BorderThickness = "0"
ContextMenuService.Placement = "Right"
ContextMenuService.PlacementTarget = "{Binding Path=., RelativeSource={RelativeSource Self}}"
x:Name = "TextBox">
<TextBox.ContextMenu>
<ContextMenu x:Name="Menu">
<ContextMenu.Template>
<ControlTemplate>
<Border CornerRadius = "5"
Background = "LightGray"
BorderThickness = "1"
BorderBrush = "Gray"
Padding = "2">
<StackPanel Orientation="Vertical">
<!-- Title -->
<TextBlock Text="Test" x:Name = "Test" />
<!-- TODO: List of matches -->
<TextBox Text = "{Binding Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, RelativeSource={RelativeSource AncestorType=ccont:vokDataGridEdit}}"
BorderThickness = "0" />
</StackPanel>
</Border>
</ControlTemplate>
</ContextMenu.Template>
</ContextMenu>
</TextBox.ContextMenu>
</TextBox>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
和代码(未显示依赖属性):
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
namespace App.Controls
{
/// <summary>
/// DataGrid Edit control (see: https://www.c-sharpcorner.com/article/wpf-routed-events/ for RoutedEvents)
/// </summary>
public class vokDataGridEdit : Control
{
static vokDataGridEdit()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(vokDataGridEdit), new FrameworkPropertyMetadata(typeof(vokDataGridEdit)));
}
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
// Demo purpose only, check for previous instances and remove the handler first
if (this.GetTemplateChild("TextBox") is TextBox button)
{
button.PreviewMouseLeftButtonDown += this.SelectContentPreparation;
button.GotKeyboardFocus += this.SelectContent;
button.MouseDoubleClick += this.SelectContent;
//button.GotFocus += this.SelectContent;
}
}
/// <summary>
/// Prepare the Control to ensure it has focus before subsequent event fire
/// </summary>
private void SelectContentPreparation(object sender, MouseButtonEventArgs e)
{
if (sender is TextBox tb)
{
if (!tb.IsKeyboardFocusWithin)
{
e.Handled = true;
tb.Focus();
}
}
}
private void SelectContent(object sender, RoutedEventArgs e)
{
if (sender is TextBox tb)
{
e.Handled = true;
tb.SelectAll();
}
}
}
}