介绍
有这样一个需求,当用户双击Tab控件Header区域时, 希望可以直接编辑。对于WPF控件,提供一个ControlTemplate在加上一些Trigger就可以实现。效果如下:
代码
首先,我们需要给Tab Header设计一个ControlTemplate。类似一个TextBlock,双击进入编辑状态。 所以Xaml如下:
< Setter Property="Template"> < Setter.Value > < ControlTemplate TargetType="{x:Type local:EditableTabHeaderControl}"> < Grid > < TextBox x:Name="PART_TabHeader" Text="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Content, Mode=TwoWay}" Visibility="Collapsed"/> < TextBlock x:Name="PART_TextBlock" Text="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Content, Mode=TwoWay}"/> </ Grid > < ControlTemplate.Triggers > < Trigger Property="IsInEditMode" Value="True"> < Trigger.Setters > < Setter TargetName="PART_TabHeader" Property="Visibility" Value="Visible"/> < Setter TargetName="PART_TextBlock" Property="Visibility" Value="Collapsed"/> </ Trigger.Setters > </ Trigger > </ ControlTemplate.Triggers > </ ControlTemplate > </ Setter.Value > </ Setter > |
接下来,我们需要定义个“EditableTabHeaderControl”类,它具有控制TextBox和TextBlock的能力。如下:
namespace EditableTabHeaderDemo { using System; using System.Windows; using System.Windows.Controls; using System.Windows.Input; using System.Windows.Threading; /// <summary> /// Header Editable TabItem /// </summary> [TemplatePart(Name = "PART_TabHeader" , Type = typeof (TextBox))] public class EditableTabHeaderControl : ContentControl { /// <summary> /// Dependency property to bind EditMode with XAML Trigger /// </summary> private static readonly DependencyProperty IsInEditModeProperty = DependencyProperty.Register( "IsInEditMode" , typeof ( bool ), typeof (EditableTabHeaderControl)); private TextBox textBox; private string oldText; private DispatcherTimer timer; private delegate void FocusTextBox(); /// <summary> /// Gets or sets a value indicating whether this instance is in edit mode. /// </summary> public bool IsInEditMode { get { return ( bool ) this .GetValue(IsInEditModeProperty); } set { if ( string .IsNullOrEmpty( this .textBox.Text)) { this .textBox.Text = this .oldText; } this .oldText = this .textBox.Text; this .SetValue(IsInEditModeProperty, value); } } /// <summary> /// When overridden in a derived class, is invoked whenever application code or internal processes call <see cref="M:System.Windows.FrameworkElement.ApplyTemplate"/>. /// </summary> public override void OnApplyTemplate() { base .OnApplyTemplate(); this .textBox = this .Template.FindName( "PART_TabHeader" , this ) as TextBox; if ( this .textBox != null ) { this .timer = new DispatcherTimer(); this .timer.Tick += TimerTick; this .timer.Interval = TimeSpan.FromMilliseconds(1); this .LostFocus += TextBoxLostFocus; this .textBox.KeyDown += TextBoxKeyDown; this .MouseDoubleClick += EditableTabHeaderControlMouseDoubleClick; } } /// <summary> /// Sets the IsInEdit mode. /// </summary> /// <param name="value">if set to <c>true</c> [value].</param> public void SetEditMode( bool value) { this .IsInEditMode = value; this .timer.Start(); } private void TimerTick( object sender, EventArgs e) { this .timer.Stop(); this .MoveTextBoxInFocus(); } private void MoveTextBoxInFocus() { if ( this .textBox.CheckAccess()) { if (! string .IsNullOrEmpty( this .textBox.Text)) { this .textBox.CaretIndex = 0; this .textBox.Focus(); } } else { this .textBox.Dispatcher.BeginInvoke(DispatcherPriority.Render, new FocusTextBox( this .MoveTextBoxInFocus)); } } private void TextBoxKeyDown( object sender, KeyEventArgs e) { if (e.Key == Key.Escape) { this .textBox.Text = oldText; this .IsInEditMode = false ; } else if (e.Key == Key.Enter) { this .IsInEditMode = false ; } } private void TextBoxLostFocus( object sender, RoutedEventArgs e) { this .IsInEditMode = false ; } private void EditableTabHeaderControlMouseDoubleClick( object sender, MouseButtonEventArgs e) { if (e.LeftButton == MouseButtonState.Pressed) { this .SetEditMode( true ); } } } } |
这里有一个问题,当控件进入编辑状态,TextBox变为可见状态时,它不能自动获得focus。一种解决办法是挂一个Timer,每1毫秒轮询一次,检查状态并控制focus。
现在就来添加一个WPF TabControl,并应用ItemContainerStyle。然后双击Header,可以编辑啦~
< Window x:Class="EditableTabHeaderDemo.MainWindow" xmlns:local="clr-namespace:EditableTabHeaderDemo" Title="EditableTabHeaderDemo" Height="300" Width="500"> < Window.Resources > < Style x:Key="EditableTabHeaderControl" TargetType="{x:Type local:EditableTabHeaderControl}"> <!-- The template specified earlier will come here !--> </ Style > < Style x:Key="ItemContainerStyle" TargetType="TabItem"> < Setter Property="HeaderTemplate"> < Setter.Value > < DataTemplate > < local:EditableTabHeaderControl Style="{StaticResource EditableTabHeaderControl}"> < local:EditableTabHeaderControl.Content > < Binding Path="Name" Mode="TwoWay"/> </ local:EditableTabHeaderControl.Content > </ local:EditableTabHeaderControl > </ DataTemplate > </ Setter.Value > </ Setter > </ Style > < DataTemplate x:Key="ContentTemplate"> < Grid > < TextBlock HorizontalAlignment="Left" Text="{Binding Name}"/> < TextBlock HorizontalAlignment="Center" Text="{Binding City}"/> </ Grid > </ DataTemplate > </ Window.Resources > < Grid > < TabControl Grid.Row="0" ItemsSource="{Binding Data}" ItemContainerStyle="{StaticResource ItemContainerStyle}" ContentTemplate="{StaticResource ContentTemplate}" /> </ Grid > </ Window > |
开发工具
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许可证
本文以及示例代码文件遵循The Code Project Open License(CPOL)。