我有$ P $使用键按下事件所键入的文本框中pvented数字。但通过鼠标使用​​Ctrl + V或粘贴内容时，该号码被输入到文本框中。如何prevent呢？我必须让所有的文本粘贴/输入除号。

I have prevented numbers from being typed in text box using key down event. But when using Ctrl+V or pasting content through mouse, the numbers are being entered in the text box. How to prevent this? I have to allow all text to be pasted/typed except numbers.

推荐答案

在比较简单的方法是检查使用框TextChanged 事件文本。如果文字是有效的，保存它的一个副本在一个字符串变量。如果无效，显示一条消息，然后恢复从变量的文字：

On quite simple approach would be to check the text using the TextChanged event. If the text is valid, store a copy of it in a string variable. If it is not valid, show a message and then restore the text from the variable:

string _latestValidText = string.Empty;
private void TextBox_TextChanged(object sender, EventArgs e)
{
    TextBox target = sender as TextBox;
    if (ContainsNumber(target.Text))
    {
        // display alert and reset text
        MessageBox.Show("The text may not contain any numbers.");
        target.Text = _latestValidText;
    }
    else
    {
        _latestValidText = target.Text;
    }
}
private static bool ContainsNumber(string input)
{
    return Regex.IsMatch(input, @"\d+");
}

这将处理的任何数字出现在文本中，无论在哪里，有多少次，他们可能会出现。

This will handle any occurrence of numbers in the text, regardless of where or how many times they may appear.