检测文本框中的Tab键按下 [英] Detect the Tab Key Press in TextBox

问题描述

我正在尝试检测 TextBox 中的 Tab 键按下.我知道Tab键不会触发 KeyDown ， KeyUp 或 KeyPress 事件.我发现:在Internet中检测BlackWasp的Windows窗体中的Tab键.他们建议覆盖我做过的ProcessCmdKey，但也不会触发.是否存在检测Tab键按下的可靠方法?

I am trying to detect the Tab key press in a TextBox. I know that the Tab key does not trigger the KeyDown, KeyUp or the KeyPress events. I found: Detecting the Tab Key in Windows Forms of BlackWasp in the internet. They suggest to override the ProcessCmdKey, which I did, but it does not get triggered either. Is there a reliable way to detect the Tab Key press?

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{

    bool baseResult = base.ProcessCmdKey(ref msg, keyData);

    if (keyData == Keys.Tab && textBox_AllUserInput.Focused)
    {
        MessageBox.Show("Tab key pressed.");
        return true;
    }
    if (keyData == (Keys.Tab | Keys.Shift) && textBox_AllUserInput.Focused)
    {
        MessageBox.Show("Shift-Tab key pressed.");
        return true;
    }

    return baseResult;
}

根据科迪·格雷的建议，我将代码更改如下:

According to Cody Gray's suggestion, I changed the code as follows:

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
    {
        if (keyData == Keys.Tab && textBox_AllUserInput.Focused)
        {
            MessageBox.Show("Tab key pressed.");        }
        if (keyData == (Keys.Tab | Keys.Shift) && textBox_AllUserInput.Focused)
        {
            MessageBox.Show("Shift-Tab key pressed.");        }

        return base.ProcessCmdKey(ref msg, keyData);
    }

问题在于它无法捕获Tab键.

The problem is that it does not capture the Tab key press.

推荐答案

某些按键，例如 TAB ， RETURN ， ESC 和箭头键通常被某些控件忽略，因为它们不被视为输入键按下.

Some key presses, such as the TAB, RETURN, ESC, and arrow keys, are typically ignored by some controls because they are not considered input key presses.

您可以处理

You can handle PreviewKeyDown event of your control to handle those key strokes and set them as input key.

private void textBox1_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
    if(e.KeyData == Keys.Tab)
    {
        MessageBox.Show("Tab");
        e.IsInputKey = true;
    }
    if (e.KeyData == (Keys.Tab | Keys.Shift))
    {
        MessageBox.Show("Shift + Tab");
        e.IsInputKey = true;
    }
}

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