如何限制c#中的文本框只接收数字和(点".";或逗号"，")，在"或“
本文关键字：quot 何限制 文本 数字 | 更新日期: 2023-09-27 18:09:29
我正在尝试开发一个代码来限制TextBox使用c#只允许数字输入+逗号("，")或点(".")+点或逗号后只有2个数字这样可以看到可以输入的数字:
3213,04 = OK
3211,664 = Not
32.31 = OK
32.3214 = Not
334,,00 = Not
3247,.00 = Not
214.,00 = Not
32.. = Not
8465,0 = Ok
654.0 = Ok
明白我的目标吗?我开发的代码如下
private void txtValormetrocubico_KeyPress(object sender, KeyPressEventArgs e)
{
if (txtValormetrocubico.TextLength >= 0 && (e.KeyChar == (char)Keys.OemPeriod || e.KeyChar == (char)Keys.Oemcomma))
{
//tests
}
else
{
if (!char.IsControl(e.KeyChar)
&& !char.IsDigit(e.KeyChar)
&& e.KeyChar != '.' && e.KeyChar != ',')
{
e.Handled = true;
}
// only allow one decimal point
if (e.KeyChar == '.' && (sender as TextBox).Text.IndexOf('.') > -1)
{
e.Handled = true;
}
if (e.KeyChar == ',' && (sender as TextBox).Text.IndexOf(',') > -1)
{
e.Handled = true;
}
}
}
这是我写的辅助函数
private bool alreadyExist(string _text , ref char KeyChar)
{
if (_text.IndexOf('.')>-1)
{
KeyChar = '.';
return true;
}
if (_text.IndexOf(',') > -1)
{
KeyChar = ',';
return true;
}
return false;
}
这是你的按键事件处理程序
private void txtValormetrocubico_KeyPress(object sender, KeyPressEventArgs e)
{
if (!char.IsControl(e.KeyChar)
&& !char.IsDigit(e.KeyChar)
&& e.KeyChar != '.' && e.KeyChar != ',')
{
e.Handled = true;
}
//check if '.' , ',' pressed
char sepratorChar='s';
if (e.KeyChar == '.' || e.KeyChar == ',')
{
// check if it's in the beginning of text not accept
if (txtValormetrocubico.Text.Length == 0) e.Handled = true;
// check if it's in the beginning of text not accept
if (txtValormetrocubico.SelectionStart== 0 ) e.Handled = true;
// check if there is already exist a '.' , ','
if (alreadyExist(txtValormetrocubico.Text , ref sepratorChar)) e.Handled = true;
//check if '.' or ',' is in middle of a number and after it is not a number greater than 99
if (txtValormetrocubico.SelectionStart != txtValormetrocubico.Text.Length && e.Handled ==false)
{
// '.' or ',' is in the middle
string AfterDotString = txtValormetrocubico.Text.Substring(txtValormetrocubico.SelectionStart);
if (AfterDotString.Length> 2)
{
e.Handled = true;
}
}
}
//check if a number pressed
if (Char.IsDigit(e.KeyChar))
{
//check if a coma or dot exist
if (alreadyExist(txtValormetrocubico.Text ,ref sepratorChar))
{
int sepratorPosition = txtValormetrocubico.Text.IndexOf(sepratorChar);
string afterSepratorString = txtValormetrocubico.Text.Substring(sepratorPosition + 1 );
if (txtValormetrocubico.SelectionStart > sepratorPosition && afterSepratorString.Length >1)
{
e.Handled = true;
}
}
}
}
我认为你需要像蒙屏文本框控件这样的东西这里有一些参考
http://msdn.microsoft.com/en-us/library/kkx4h3az.aspxhttp://www.c-sharpcorner.com/uploadfile/mahesh/maskedtextbox-in-C-Sharp/
另一种方法是使用正则表达式您可以创建一个通用函数并在keypress事件中调用它，此代码是一个通用实例。
validate_textBox是一般函数
private void validate_textBox(TextBox _text, KeyPressEventArgs e)
{
if (!char.IsControl(e.KeyChar)
&& !char.IsDigit(e.KeyChar)
&& e.KeyChar != '.' && e.KeyChar != ',')
{
e.Handled = true;
}
if (!char.IsControl(e.KeyChar)
&& !char.IsDigit(e.KeyChar)
&& e.KeyChar != '.' && e.KeyChar != ',')
{
e.Handled = true;
}
//check if '.' , ',' pressed
char sepratorChar = 's';
if (e.KeyChar == '.' || e.KeyChar == ',')
{
// check if it's in the beginning of text not accept
if (_text.Text.Length == 0) e.Handled = true;
// check if it's in the beginning of text not accept
if (_text.SelectionStart == 0) e.Handled = true;
// check if there is already exist a '.' , ','
if (alreadyExist(_text.Text, ref sepratorChar)) e.Handled = true;
//check if '.' or ',' is in middle of a number and after it is not a number greater than 99
if (_text.SelectionStart != _text.Text.Length && e.Handled == false)
{
// '.' or ',' is in the middle
string AfterDotString = _text.Text.Substring(_text.SelectionStart);
if (AfterDotString.Length > 2)
{
e.Handled = true;
}
}
}
//check if a number pressed
if (Char.IsDigit(e.KeyChar))
{
//check if a coma or dot exist
if (alreadyExist(_text.Text, ref sepratorChar))
{
int sepratorPosition = _text.Text.IndexOf(sepratorChar);
string afterSepratorString = _text.Text.Substring(sepratorPosition + 1);
if (_text.SelectionStart > sepratorPosition && afterSepratorString.Length > 1)
{
e.Handled = true;
}
}
}
}
然后你可以像下面这样为每个文本框调用函数
private void txtValormetrocubico_KeyPress(object sender, KeyPressEventArgs e)
{
validate_textBox(sender as TextBox, e);
}
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
validate_textBox(sender as TextBox, e);
}
我不知道谁在2021年寻找这个，但这里有一个解决方案覆盖ontextchange事件!欢呼声
protected override void OnTextChanged(EventArgs e)
{
base.OnTextChanged(e);
String text = "";
Char[] chars = this.Text.ToString().ToCharArray();
int total_dots = 0;
int dot_pos = 0;
int char_pos = 0;
foreach (Char c in chars )
{
char_pos++;
if (Char.IsDigit(c))
{
if(dot_pos > 0) { //dot already exists
if (char_pos <= dot_pos + 2) //only accept two numbers after dot (3.99)
{
text += c.ToString();
}
}
else
{
text += c.ToString();
}
}
if(c == '.' || c == ',')
{
total_dots++;
if (char_pos > 1 && total_dots <=1) //only accept one dot and if the dot is not in first position
{
text += c.ToString();
dot_pos = char_pos;
}
}
}
this.Text = text;
this.SelectionStart = this.Text.Length;
}