Question

我有一个文本框，我只想要数字。但如果我打错了号码，我就无法退格以纠正它。如何允许退格键工作。感谢

    private void amount_PaidTextBox_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (Char.IsNumber(e.KeyChar) != true)
        {
            e.Handled = true;
        }
    }

Answer 1

您可以添加一项检查以允许控制字符：

if (Char.IsControl(e.KeyChar) != true && Char.IsNumber(e.KeyChar) != true)
{
    e.Handled = true;
}

更新：回应person-b对代码的评论/他建议采用以下风格（这也是我个人写的方式）：

if (!Char.IsControl(e.KeyChar) && !Char.IsNumber(e.KeyChar))
{
    e.Handled = true;
}

Answer 2

正确答案是：

private void amount_PaidTextBox_KeyPress(object sender, KeyPressEventArgs e)
{
    e.Handled = !сhar.IsNumber(e.KeyChar) && (e.KeyChar != '\b');
}

Answer 3

您还可以覆盖TextChanged事件：

private void textBox1_TextChanged(object sender, EventArgs e)
{
    string text = (sender as TextBox).Text;

    StringBuilder builder = new StringBuilder(String.Empty);

    foreach (char character in text)
    {
        if (Char.IsDigit(character))
        {
            builder.Append(character);
        }
    }

    (sender as TextBox).Text = builder.ToString();
}

请注意，您必须添加代码才能设置插入位置。

Answer 4

private void amount_PaidTextBox_KeyPress(object sender, KeyPressEventArgs e)
{
     if (!Char.IsNumber(e.KeyChar) && e.KeyCode != Keys.Back)
          e.Handled = True;
}

Answer 5

以上格式略微清晰：

 private void amount_PaidTextBox_KeyPress(object sender, KeyPressEventArgs e)
 {
   e.Handled = !(Char.IsNumber(e.KeyChar) || (e.KeyChar==Keys.Back));
 }

Answer 6

我发现以下效果很好。它包括允许退格，箭头键删除键等的额外例外。 How to allow only numeric (0-9) in HTML inputbox using jQuery?

Answer 7

private void txt_KeyPress(object sender, KeyPressEventArgs e)
{
    if (Char.IsDigit(e.KeyChar) || e.KeyChar == '\b')
    {
        // Allow Digits and BackSpace char
    }        
    else
    {
        e.Handled = true;
    }
}

参考链接：Masking Textbox to accept only decimals小数/ 12209854＃12209854

Answer 8

您可以在按键事件中使用以下内容：

      private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (!Char.IsDigit(e.KeyChar) & (e.KeyChar != 8)) e.Handled = true; 
    }

Answer 9

按下您的文本框，然后输入事件从事件双击 KeyPress 然后写下这段代码

if( e.KeyChar <'0' || e.KeyChar > '9' )
if(e.KeyChar!=08)
e.Handled=true;

仅为Numbers屏蔽文本框但不接受BackSpace

9 个答案: