C# 扩展控件';s能力
假设我想扩展工具箱中的所有文本框,以便在引发“GotFocus”事件时执行某些操作。 比如,运行一行代码,指示他们选择All() 我可以用什么最有效的方式将这种行为/事件处理添加到我的所有文本框中C# 扩展控件';s能力,c#,.net,wpf,xaml,C#,.net,Wpf,Xaml,假设我想扩展工具箱中的所有文本框,以便在引发“GotFocus”事件时执行某些操作。 比如,运行一行代码,指示他们选择All() 我可以用什么最有效的方式将这种行为/事件处理添加到我的所有文本框中 我只是以TextBox为例,因为我计划在今后的WPF库中对其他控件执行类似的操作。您希望使用附加的行为来完成此操作。下面是我目前用来做这件事的代码,它涵盖了一些奇怪的边缘情况 public class TextBoxBehaviors { public static readonly Depe
我只是以TextBox为例,因为我计划在今后的WPF库中对其他控件执行类似的操作。您希望使用附加的行为来完成此操作。下面是我目前用来做这件事的代码,它涵盖了一些奇怪的边缘情况
public class TextBoxBehaviors
{
public static readonly DependencyProperty SelectAllOnFocusProperty = DependencyProperty.RegisterAttached("SelectAllOnFocus", typeof(bool), typeof(TextBoxBehaviors), new PropertyMetadata(false, OnSelectAllOnFocusChanged));
public static DependencyProperty GetSelectAllOnFocus(TextBox element)
{
return (DependencyProperty)element.GetValue(SelectAllOnFocusProperty);
}
public static void SetSelectAllOnFocus(TextBox element, bool value)
{
element.SetValue(SelectAllOnFocusProperty, value);
}
private static void OnSelectAllOnFocusChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var comboBox = d as ComboBox;
if (comboBox != null)
{
comboBox.Loaded += ComboBox_Loaded;
return;
}
var textBox = d as TextBox;
if (textBox == null) { return; }
if ((bool)e.OldValue)
{
textBox.PreviewMouseDown -= TextBox_PreviewMouseDown;
textBox.GotFocus -= TextBox_GotFocus;
}
if (!(bool)e.NewValue)
return;
textBox.PreviewMouseDown += TextBox_PreviewMouseDown;
textBox.GotFocus += TextBox_GotFocus;
}
private static void ComboBox_Loaded(object sender, RoutedEventArgs e)
{
var comboBox = sender as ComboBox;
var comboText = comboBox?.Template.FindName("PART_EditableTextBox", comboBox) as TextBox;
comboText?.SetValue(SelectAllOnFocusProperty, comboBox.GetValue(SelectAllOnFocusProperty));
}
private static void TextBox_GotFocus(object sender, RoutedEventArgs e)
{
var textBox = sender as TextBox;
if (textBox == null) { return; }
// We need to dispatch this in case someone is changing the text during the GotFocus
// event. In that case, we want to select it all after they're done.
Application.Current.Dispatcher.BeginInvoke(DispatcherPriority.Normal,
(Action)(() => TextBox_DoSelectAll(textBox)));
}
private static void TextBox_DoSelectAll(TextBox textBox)
{
if (!textBox.IsFocused) return;
textBox.CaretIndex = textBox.Text.Length;
textBox.SelectAll();
}
private static void TextBox_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
var textBox = sender as TextBox;
if (textBox == null) { return; }
if (textBox.IsFocused)
return;
textBox.Focus();
e.Handled = true; // Prevent default TextBox behavior from deselecting text on mouse up
}
}
用法:
<TextBox beh:TextBoxBehaviors.SelectAllOnFocus="True" />
或在所有文本框上设置:
<Style TargetType="{x:Type TextBox}">
<Setter Property="beh:TextBoxBehaviors.SelectAllOnFocus" />
</Style>
您希望使用附加的行为来完成此操作。下面是我目前用来做这件事的代码,它涵盖了一些奇怪的边缘情况
public class TextBoxBehaviors
{
public static readonly DependencyProperty SelectAllOnFocusProperty = DependencyProperty.RegisterAttached("SelectAllOnFocus", typeof(bool), typeof(TextBoxBehaviors), new PropertyMetadata(false, OnSelectAllOnFocusChanged));
public static DependencyProperty GetSelectAllOnFocus(TextBox element)
{
return (DependencyProperty)element.GetValue(SelectAllOnFocusProperty);
}
public static void SetSelectAllOnFocus(TextBox element, bool value)
{
element.SetValue(SelectAllOnFocusProperty, value);
}
private static void OnSelectAllOnFocusChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var comboBox = d as ComboBox;
if (comboBox != null)
{
comboBox.Loaded += ComboBox_Loaded;
return;
}
var textBox = d as TextBox;
if (textBox == null) { return; }
if ((bool)e.OldValue)
{
textBox.PreviewMouseDown -= TextBox_PreviewMouseDown;
textBox.GotFocus -= TextBox_GotFocus;
}
if (!(bool)e.NewValue)
return;
textBox.PreviewMouseDown += TextBox_PreviewMouseDown;
textBox.GotFocus += TextBox_GotFocus;
}
private static void ComboBox_Loaded(object sender, RoutedEventArgs e)
{
var comboBox = sender as ComboBox;
var comboText = comboBox?.Template.FindName("PART_EditableTextBox", comboBox) as TextBox;
comboText?.SetValue(SelectAllOnFocusProperty, comboBox.GetValue(SelectAllOnFocusProperty));
}
private static void TextBox_GotFocus(object sender, RoutedEventArgs e)
{
var textBox = sender as TextBox;
if (textBox == null) { return; }
// We need to dispatch this in case someone is changing the text during the GotFocus
// event. In that case, we want to select it all after they're done.
Application.Current.Dispatcher.BeginInvoke(DispatcherPriority.Normal,
(Action)(() => TextBox_DoSelectAll(textBox)));
}
private static void TextBox_DoSelectAll(TextBox textBox)
{
if (!textBox.IsFocused) return;
textBox.CaretIndex = textBox.Text.Length;
textBox.SelectAll();
}
private static void TextBox_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
var textBox = sender as TextBox;
if (textBox == null) { return; }
if (textBox.IsFocused)
return;
textBox.Focus();
e.Handled = true; // Prevent default TextBox behavior from deselecting text on mouse up
}
}
用法:
<TextBox beh:TextBoxBehaviors.SelectAllOnFocus="True" />
或在所有文本框上设置:
<Style TargetType="{x:Type TextBox}">
<Setter Property="beh:TextBoxBehaviors.SelectAllOnFocus" />
</Style>
使用26个中的@17建议的行为是一种方法。创建自定义TextBox控件并使用此控件而不是内置的TextBox控件是另一个。@mm8实际上,现在您提到我已经将其中一些控件设置为UserControls,每个控件都有自己的位和代码。我真正想要的是避免重复代码。我可以把我想要的代码应用到每个控件后面的代码中,一切都会很好,但正如我所说,我希望尽可能避免这种重复,并将这些通用指令放在一个地方。您不应该将通用代码放在UserControls中,而是放在所有UserControls中使用的自定义TextBox控件类中。使用26中@17建议的行为将是一种方法。创建自定义TextBox控件并使用此控件而不是内置的TextBox控件是另一个。@mm8实际上,现在您提到我已经将其中一些控件设置为UserControls,每个控件都有自己的位和代码。我真正想要的是避免重复代码。我可以把我想要的代码应用到每个控件后面的代码中,一切都会很好,但就像我说的,我希望尽可能避免这种重复,并将这些通用指令放在一个地方。你不应该将通用代码放在UserControls中,而是放在所有UserControls中使用的自定义TextBox控件类中。非常好,我现在开始越来越多地使用行为,它们非常有用。非常好,我现在开始越来越多地使用行为,它们非常有用。