如何使TextBox只接受字母字符？

Question

如何让TextBox只接受带空格的字母字符？

Answer 1

您可以使用以下代码段：

private void textBox1_TextChanged(object sender, EventArgs e)
{
    if (!System.Text.RegularExpressions.Regex.IsMatch(textBox1.Text, "^[a-zA-Z ]"))
    {
        MessageBox.Show("This textbox accepts only alphabetical characters");
        textBox1.Text.Remove(textBox1.Text.Length - 1);
    }
}

Answer 2

试试这个

            private void tbCustomerName_KeyPress(object sender, KeyPressEventArgs e)
    {
        e.Handled = !(char.IsLetter(e.KeyChar) || e.KeyChar == (char)Keys.Back||e.KeyChar==(char)Keys.Space);
    }

它也允许白色空间

Answer 3

您可以尝试按下在按键事件发生时提醒的代码

private void tbOwnerName_KeyPress(object sender, KeyPressEventArgs e)
    {

        //===================to accept only charactrs & space/backspace=============================================

        if (e.Handled = !(char.IsLetter(e.KeyChar) || e.KeyChar == (char)Keys.Back || e.KeyChar == (char)Keys.Space))
        {
            e.Handled = true;
            base.OnKeyPress(e);
            MessageBox.Show("enter characters only");
        }

Answer 4

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
    {
      if (!char.IsControl(e.KeyChar) && !char.IsLetter(e.KeyChar) &&
         (e.KeyChar !='.'))
        { 
          e.Handled = true;
          MessageBox.Show("Only Alphabets");
        }
    }

Answer 5

这是我的解决方案，它按计划运行：

string errmsg = "ERROR : Wrong input";
ErrorLbl.Text = errmsg;

if (e.Handled = !(char.IsLetter(e.KeyChar) || e.KeyChar == (char)Keys.Back || e.KeyChar == (char)Keys.Space))
{
  ErrorLbl.Text = "ERROR : Wrong input";
}
else ErrorLbl.Text = string.Empty;
if (ErrorLbl.Text == errmsg)
{
  Nametxt.Text = string.Empty;
}

Answer 6

在文本框的KeyPress事件中尝试以下代码

if (char.IsLetter(e.KeyChar) == false  & 
        Convert.ToString(e.KeyChar) != Microsoft.VisualBasic.Constants.vbBack)
            e.Handled = true

Answer 7

就字符限制而言，此工作正常，如果不是C或L，则对我的代码提出错误消息的任何建议

Private Sub TXTBOX_TextChanged（sender As System.Object，e As System.EventArgs）处理TXTBOX.TextChanged

    Dim allowed As String = "C,L"
    For Each C As Char In TXTBOX.Text
        If allowed.Contains(C) = False Then

            TXTBOX.Text = TXTBOX.Text.Remove(TXTBOX.SelectionStart - 1, 1)
            TXTBOX.Select(TXTBOX.Text.Count, 0)

        End If

    Next

End Sub

Answer 8

您可以尝试处理文本框的KeyPress事件

void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
    e.Handled = !(char.IsLetter(e.KeyChar) || e.KeyChar == (char)Keys.Back);
}

另外说如果你想删除一些文本允许退格，这应该对你来说非常好

编辑

上面的代码不适用于我认为你将不得不使用TextChanged事件的字段中的粘贴，但是当你必须删除不正确的字符或突出显示它并为用户放置光标时会更复杂一些进行更正或者也许您可以在用户输入完整文本并关闭控件后进行验证。

Answer 9

private void textbox1_KeyDown_1(object sender, KeyEventArgs e)
{
    if (e.Key >= Key.A && e.Key <= Key.Z)
    {
    }
    else
    {
       e.Handled = true;
    }
}

Answer 10

最简单的方法是处理TextChangedEvent并检查输入的内容：

string oldText = string.Empty;
    private void textBox2_TextChanged(object sender, EventArgs e)
    {
        if (textBox2.Text.All(chr => char.IsLetter(chr)))
        {
            oldText = textBox2.Text;
            textBox2.Text = oldText;

            textBox2.BackColor = System.Drawing.Color.White;
            textBox2.ForeColor = System.Drawing.Color.Black;
        }
        else
        {
            textBox2.Text = oldText;
            textBox2.BackColor = System.Drawing.Color.Red;
            textBox2.ForeColor = System.Drawing.Color.White;
        }
        textBox2.SelectionStart = textBox2.Text.Length;
    }

如果您愿意，这是一个免费的正则表达式版本。这将使文本框在输入错误时闪烁。请注意，它似乎也支持粘贴操作。

Answer 11

将Text_KeyPress事件中的代码写为

 private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
    {

        if (!char.IsLetter(e.KeyChar))
        {
            e.Handled = true;
        }
    }

Answer 12

这个工作绝对正常......

 private void manufacturerOrSupplierTextBox_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (char.IsControl(e.KeyChar) || char.IsLetter(e.KeyChar))
        {
            return;
        }
        e.Handled = true;
    }

Answer 13

此解决方案使用正则表达式，不允许将无效字符粘贴到文本框中并保持光标位置。

using System.Text.RegularExpressions;

int CursorWas;
string WhatItWas;

private void textBox1_Enter(object sender, EventArgs e)
    {
        WhatItWas = textBox1.Text;
    }

private void textBox1_TextChanged(object sender, EventArgs e)
    {
        if (Regex.IsMatch(textBox1.Text, "^[a-zA-Z ]*$"))
        {
            WhatItWas = textBox1.Text;
        }
        else
        {
            CursorWas = textBox1.SelectionStart == 0 ? 0 : textBox1.SelectionStart - 1;
            textBox1.Text = WhatItWas;
            textBox1.SelectionStart = CursorWas;
        }
    }

注意：textBox1_TextChanged递归调用。

Answer 14

        if (System.Text.RegularExpressions.Regex.IsMatch(textBox1.Text, "^[a-zA-Z]+$"))
        { 
        }
        else
        {
            textBox1.Text = textBox1.Text.Remove(textBox1.Text.Length - 1);
            MessageBox.Show("Enter only Alphabets");


        }

请试试这个

Answer 15

private void textBox2_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar >= '0' && e.KeyChar <= '9')
                e.Handled = true;
            else
                e.Handled = false;
        }