wpf 通过命令绑定获取点击位置
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原文地址: http://stackoverflow.com/questions/12642645/
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Get click position over command binding
提问by beta vulgaris
What I want to do is a UserControl containing a section with a grid, where something happens when clicking on the grid. I need the position of the pixel where the click happened and I'm doing all of this MVVM style. I know how I can prompt actions on my ViewModel:
我想要做的是一个 UserControl 包含一个带有网格的部分，点击网格时会发生一些事情。我需要点击发生的像素的位置，我正在做所有这些 MVVM 风格。我知道如何在我的 ViewModel 上提示操作：
<Grid>
<Grid.InputBindings>
<MouseBinding Gesture="LeftClick" Command="{Binding MinimapClick}"/>
</Grid.InputBindings>
</Grid>
My problem is now that I don't know how to retrieve the Coordinates... any ideas? I appreciate your help!
我的问题是现在我不知道如何检索坐标......有什么想法吗？我感谢您的帮助！
采纳答案by Kevin DiTraglia
How about this?
这个怎么样？
private void MinimapClick(object parameter)
{
Point mousePos = Mouse.GetPosition(myWindow);
}
If you don't have a reference to the window you could send it as a parameter (or use whatever reference point you want).
如果您没有对窗口的引用，您可以将其作为参数发送（或使用您想要的任何参考点）。
回答by beta vulgaris
KDiTraglia had the right pointerfor me... In any case I had some issues with defining the actions and binding to my ViewModel. I'll post my solution in case someone else has some problems. Here's what I've done in the xaml:
KDiTraglia为我提供了正确的指针......无论如何，我在定义操作和绑定到我的 ViewModel 时遇到了一些问题。如果其他人有问题，我会发布我的解决方案。这是我在 xaml 中所做的：
<Grid Width="100" Height="100" Grid.Column="2" Grid.Row="2" x:Name="TargetGrid">
<Grid>
<Grid.InputBindings>
<MouseBinding Gesture="LeftClick" Command="{Binding Path=TargetClick}" CommandParameter="{Binding ElementName=TargetGrid}" />
</Grid.InputBindings>
</Grid>
</Grid>
I create the UserControl and bind it to the ViewModel. In the ViewModel I implement and create the following command:
我创建了 UserControl 并将其绑定到 ViewModel。在 ViewModel 中，我实现并创建了以下命令：
public class PositioningCommand : ICommand
{
public PositioningCommand()
{
}
public void Execute(object parameter)
{
Point mousePos = Mouse.GetPosition((IInputElement)parameter);
Console.WriteLine("Position: " + mousePos.ToString());
}
public bool CanExecute(object parameter) { return true; }
public event EventHandler CanExecuteChanged;
}
public PositioningCommand TargetClick
{
get;
internal set;
}
回答by ActualRandy
I had a related issue - I wanted to capture the mouse position for click events for my ContextMenu. Problem: my menu's parent(an image control) was not recognized by the CommandParameter ElementName.
我有一个相关的问题 - 我想为我的ContextMenu捕获单击事件的鼠标位置。问题：CommandParameter ElementName 无法识别我的菜单的父级（图像控件）。
For reference, the binding error I received, priorto adding my menu to the namespace, was:
作为参考，在将菜单添加到命名空间之前，我收到的绑定错误是：
System.Windows.Data Error: 4 : Cannot find source for binding with reference 'ElementName=imgArena'. BindingExpression:(no path); DataItem=null; target element is 'MenuItem' (Name='mnuAddItem'); target property is 'CommandParameter' (type 'Object')
Apparently WPF context menus belong to a different visual tree than your control, making binding quite frustrating.
显然，WPF 上下文菜单与您的控件属于不同的可视化树，这使得绑定非常令人沮丧。
After some research, I found this simple fix, which I placed in the constructor for my code behind:
经过一番研究，我找到了这个简单的修复程序，我将其放置在后面代码的构造函数中：
NameScope.SetNameScope(mnuGrid, NameScope.GetNameScope(this));
Where "mnuGrid" is the name of my context menu.
其中“mnuGrid”是我的上下文菜单的名称。
After I did this, I was able to pass my control as a parameter to my command exactly as Beta Vulgaris did above.
完成此操作后，我能够像上面的 Beta Vulgaris 一样将我的控件作为参数传递给我的命令。
For reference, my XAML looks like this:
作为参考，我的 XAML 如下所示：
<Image Name="imgArena" >
<Image.ContextMenu>
<ContextMenu Name="mnuGrid">
<MenuItem Header="Place _Entry" Name="mnuAddItem"
Command="{Binding AddEntryCmd}"
CommandParameter="{Binding ElementName=imgArena}" />
</ContextMenu>
<Image.ContextMenu>
</Image>
