选择组合框时发生事件 [英] Event when combobox is selected

问题描述

我的问题是当在C＃（WPF）中的ComboBox中选择ComboBoxItem时，如何执行操作？

My question is how to do an action when an ComboBoxItem is Selected in a ComboBox in C# (WPF) ?

在此帖子他们处理DropDownClosed事件，但他们不处理键盘选择。

In this post they handle the DropDownClosed event but they don't handled the keyboard Selection.

所以我解释一下我的情况：

So I explain my case:

ComboBoxItems的Selected事件或ComboBox的SelectionChanged动作只有当用户选择不同的ComboBoxItem，但我想要执行动作，即使用户选择的ComboBoxItem是相同的ComboBoxItem已经选择的相同。

The events "Selected" for the ComboBoxItems or "SelectionChanged" for the ComboBox do the action only when the user select an different ComboBoxItem, but I would like that the action be execute even if the ComboBoxItem that the user select is the same that the ComboBoxItem already selected.

我尝试用PreviewMouseLeftButtonDown，但如果用户用键盘选择或只是保持鼠标按，然后选择，它不工作。

I try with "PreviewMouseLeftButtonDown", but if the user select with keyboard or just keep the mouse press and then select, it doesn't work.

在我的情况下，我选择一个项目时必须打开一个窗口：

In my situation, I have to open a window when I select an Item:

private void cmiCCSelect_Selected(object sender, RoutedEventArgs e)
{
    cCEntityWindow.ShowDialog();
}

但是如果用户关闭此窗口并重新选择相同的项目不工作。我必须选择另一个，然后重新选择相同的事件选择可以执行。

But if the user close this window and re-select the same Item, it doesn't work. I have to select an other and after re-select the same for the Event "Selected" can be execute.

任何人都可以帮助我吗？

Can anybody help me?

推荐答案

我终于找到了答案：

你需要处理SelectionChanged事件和DropDownClosed像这样：

You need to handle BOTH the SelectionChanged event and the DropDownClosed like this:

在XAML中：

<ComboBox Name="cmbSelect" SelectionChanged="ComboBox_SelectionChanged" DropDownClosed="ComboBox_DropDownClosed">
    <ComboBoxItem>1</ComboBoxItem>
    <ComboBoxItem>2</ComboBoxItem>
    <ComboBoxItem>3</ComboBoxItem>
</ComboBox>

在C＃中：

private bool handle = true;
private void ComboBox_DropDownClosed(object sender, EventArgs e) {
    if(handle)Handle();
    handle = true;
}

private void ComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e) {
    ComboBox cmb = sender as ComboBox;
    handle = !cmb.IsDropDownOpen;
    Handle();
}

private void Handle() {
    switch (cmbSelect.SelectedItem.ToString().Split(new string[] { ": " }, StringSplitOptions.None).Last())
    { 
        case "1":
            //Handle for the first combobox
            break;
        case "2":
            //Handle for the second combobox
            break;
        case "3":
            //Handle for the third combobox
            break;
    }
}

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