我在窗口上有一个复选框控件。我想执行一个命令,调用相关视图模型中的方法。我还需要复选框的值。我无法找到一种将命令与复选框关联的方法。 有人做过这个吗?
<CheckBox Content="CheckBox"
Command="{Binding YourCommand}"
CommandParameter="{Binding IsChecked, RelativeSource={RelativeSource Self}}" />
CommandParameter="{Binding IsChecked, RelativeSource={RelativeSource Self}, Mode=OneWay}
将 CommandParameter 绑定到 CheckBox 的值。 - Wallace Kelly<CheckBox IsChecked="{Binding ServiceOrderItemTask.IsCompleted, Mode=TwoWay}" Content="{Binding ServiceOption.Name}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Checked">
<i:InvokeCommandAction Command="{Binding DataContext.IsCompletedCheckedCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type t:RadGridView}}}" CommandParameter="{Binding}"/>
</i:EventTrigger>
<i:EventTrigger EventName="Unchecked">
<i:InvokeCommandAction Command="{Binding DataContext.IsCompletedUncheckedCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type t:RadGridView}}}" CommandParameter="{Binding}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
xmlns:t="http://schemas.telerik.com/2008/xaml/presentation"
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
- jo_dman<CheckBox CommandParameter="{Binding}"
Command="{Binding DataContext.YourCommand,
RelativeSource={RelativeSource FindAncestor,
AncestorType={x:Type UserControl}}}"
Content="{Binding Path=Name}">
CheckBox
具有到模型的 IsChecked
绑定,它也可以工作,因此您可以跟踪模型更改而无需挂钩 INotifyPropertyChanged
,当您在集合中有很多复选框时非常方便。 - AntonKSystem.Windows.Interactivity
添加到项目的引用中。xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
。<CheckBox IsChecked="{Binding SomeBoolProperty, Mode=OneWay}" Content="Check Meee!">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Checked">
<i:InvokeCommandAction Command="{Binding MyOnCheckedCommand}"/>
</i:EventTrigger>
<i:EventTrigger EventName="Unchecked">
<i:InvokeCommandAction Command="{Binding MyOnUncheckedCommand}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</CheckBox>
我在ViewModel上实现INotifyPropertyChanged
如下:
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string name) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
我的 ViewModel 的 SomeBoolProperty
现在看起来像这样:
private bool _SomeBoolProperty = false;
public bool SomeBoolProperty {
get => _SomeBoolProperty;
set {
_SomeBoolProperty = value;
OnPropertyChanged(nameof(SomeBoolProperty));
}
}
我使用RelayCommand作为命令实现,从这里获得:https://dev59.com/dGEh5IYBdhLWcg3wjEDn#22286816。
我的ViewModel上的命令看起来像这样:
public ICommand MyOnCheckedCommand { get; } = new RelayCommand(o => {
// Do something here.
SomeBoolProperty = true;
});
public ICommand MyOnUncheckedCommand { get; } = new RelayCommand(o => {
// Do something else here.
SomeBoolProperty = false;
});
我遇到这个问题是因为想要找到一种方法重用我已经在ViewModel中拥有的两个命令。其中一个在选中时调用,另一个在取消选中时调用。我还在一些按钮上使用它们,所以不想添加额外的参数化命令。人们在这里问有关ViewModel实现的问题,因此添加了这个答案以补充Igor_S的答案。希望有所帮助。
我来晚了... 我使用了Rohit Vats的答案,然后写出了这段代码。
这个例子是一个可工作的代码片段,它只是为了帮助理解每个方面。它是一个可以是活动或非活动状态的图钉,并且它使用了DelegateCommand。你也可以使用RelayCommand或任何其他类似的类来完成同样的工作。
命令:
using System.Windows.Input;
namespace HQ.Wpf.Util.Command
{
public class StandardCommand
{
public static RoutedUICommand PinPropertyGrid = new RoutedUICommand("Pin property grid", "PinPropertyGrid", typeof(StandardCommand));
Xaml:
<CheckBox HorizontalAlignment="Right"
VerticalAlignment="Top"
Margin="2,0,3,0"
Command="{Binding CommandPinPropertyGrid}"
CommandParameter="{Binding IsChecked, RelativeSource={RelativeSource Self}}">
<CheckBox.Template>
<ControlTemplate TargetType="{x:Type CheckBox}">
<Grid>
<Image x:Name="ImagePushpin" Width="16" Height="16" Source="pack://application:,,,/WpfUtil;component/Images/PushpinUnpinned16x16.png" />
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter TargetName="ImagePushpin" Property="Source" Value="pack://application:,,,/WpfUtil;component/Images/PushpinPinned16x16.png" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</CheckBox.Template>
</CheckBox>
模型:
public MainWindowViewModel()
{
CommandPinPropertyGrid = new DelegateCommand<bool>(PinPropertyGrid);
...
// ******************************************************************
public DelegateCommand<bool> CommandPinPropertyGrid { get; private set; }
public void PinPropertyGrid(bool pinned)
{
this.IsPropertyGridPinned = pinned;
}
DelegateCommand:
using System;
using System.Windows.Input;
namespace HQ.Wpf.Util.Command
{
/// <summary>
/// Represents a command that forwards the <c>Execute</c> and <c>CanExecute</c> calls to specified delegates.
/// </summary>
public class DelegateCommand<T> : ICommand
{
private readonly Action<T> _executeCallback;
private readonly Predicate<T> _canExecuteCallback;
/////////////////////////////////////////////////////////////////////////////////////////////////////
// OBJECT
/////////////////////////////////////////////////////////////////////////////////////////////////////
/// <summary>
/// Initializes a new instance of the <see cref="DelegateCommand<T>"/> class.
/// </summary>
/// <param name="executeCallback">The execute callback delegate.</param>
public DelegateCommand(Action<T> executeCallback)
: this(executeCallback, null)
{
// No-op
}
/// <summary>
/// Initializes a new instance of the <see cref="DelegateCommand<T>"/> class.
/// </summary>
/// <param name="executeCallback">The execute callback delegate.</param>
/// <param name="canExecuteCallback">The can execute callback delegate.</param>
public DelegateCommand(Action<T> executeCallback, Predicate<T> canExecuteCallback)
{
if (executeCallback == null)
throw new ArgumentNullException("executeCallback");
this._executeCallback = executeCallback;
this._canExecuteCallback = canExecuteCallback;
}
/////////////////////////////////////////////////////////////////////////////////////////////////////
// INTERFACE IMPLEMENTATION
/////////////////////////////////////////////////////////////////////////////////////////////////////
#region ICommand Members
/// <summary>
/// Defines the method that determines whether the command can execute in its current state.
/// </summary>
/// <param name="parameter">Data used by the command. If the command does not require data to be passed, this object can be set to <see langword="null"/>.</param>
/// <returns>
/// <c>true</c> if this command can be executed; otherwise, <c>false</c>.
/// </returns>
public bool CanExecute(object parameter)
{
return (this._canExecuteCallback == null) ? true : this._canExecuteCallback((T)parameter);
}
/// <summary>
/// Occurs when changes occur that affect whether or not the command should execute.
/// </summary>
public event EventHandler CanExecuteChanged
{
add
{
if (this._canExecuteCallback != null)
CommandManager.RequerySuggested += value;
}
remove
{
if (this._canExecuteCallback != null)
CommandManager.RequerySuggested -= value;
}
}
/// <summary>
/// Defines the method to be called when the command is invoked.
/// </summary>
/// <param name="parameter">Data used by the command. If the command does not require data to be passed, this object can be set to <see langword="null"/>.</param>
public void Execute(object parameter)
{
this._executeCallback((T)parameter);
}
#endregion // ICommand Members
}
}
当您仅需要复选框的状态(已选或未选)时,您不需要参数。当您使用以下代码时,您可以检测复选框的状态:
CheckBox box = e.OriginalSource as CheckBox;
if(box.IsChecked.Value)
DoThis();
else
DoAnotherMethod();
"e" 是 Command 中的 ExecutedRoutedEventArgs 参数。你需要使用 box.IsChecked.Value,因为 box.IsChecked 的类型是 bool?。