当选择1如何取消选择其他列表框 [英] how to deselect other listBoxes when 1 is selected

问题描述

我有3个列表框，我想在选择其中1到取消选择其他.我怎样才能做到这一点? 我尝试将focused属性设置为false，但是c#不允许分配给focused属性.

I have 3 listBoxes and I want to deselect others when 1 of them is selected. How can I do this? I have tried setting the focused property to false, but c# doesn't allow assigning to the focused property.

推荐答案

假定您有三个列表框，请执行以下操作.当特定列表框更改选择时，此代码将清除所有其他列表框的选择.您可以通过设置其SelectedIndex = -1清除列表框选择.

Assuming you have three list boxes, do the following. This code will clear the selection of every other list box when a particular list box changes selections. You can clear a list box selection by setting its SelectedIndex = -1.

private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    if (listBox1.SelectedIndex > -1)
    {
        listBox2.SelectedIndex = -1;
        listBox3.SelectedIndex = -1;
    }
}

private void listBox2_SelectedIndexChanged(object sender, EventArgs e)
{
    if (listBox2.SelectedIndex > -1)
    {
        listBox1.SelectedIndex = -1;
        listBox3.SelectedIndex = -1;
    }
}

private void listBox3_SelectedIndexChanged(object sender, EventArgs e)
{
    if (listBox3.SelectedIndex > -1)
    {
        listBox1.SelectedIndex = -1;
        listBox2.SelectedIndex = -1;
    }
}

if (listBox#.SelectedIndex > -1)是必需的，因为通过代码设置列表框的SelectedIndex也会触发其SelectedIndexChanged事件，否则将在所有列表框被选中时清除所有列表框.

The if (listBox#.SelectedIndex > -1) is necessary because setting the SelectedIndex of a list box via code will also trigger its SelectedIndexChanged event, which would otherwise cause all list boxes to clear any time one of them was selected.

或者，如果表单上只有这三个列表框，则可以将其合并为一种方法.将所有三个列表框链接到此事件方法:

Alternatively, if you only have those three list boxes on your form, then you could consolidate it into one method. Link all three list boxes to this event method:

private void listBox_SelectedIndexChanged(object sender, EventArgs e)
{
    ListBox thisListBox = sender as ListBox;
    if (thisListBox == null || thisListBox.SelectedIndex == 0)
    {
        return;
    }

    foreach (ListBox loopListBox in this.Controls)
    {
        if (thisListBox != loopListBox)
        {
            loopListBox.SelectedIndex = -1;
        }
    }
}

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