如何限制 C# 中的文本框只接收数字和（点“.”或逗号“，”），在“。”之后 或 "," 只允许 2 个数字字符
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/16050749/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How restrict textbox in C# to only receive numbers and (dot "." or comma ","), after "." or "," only allow 2 number characters
提问by felipe Salomao
i am trying develop a code to restrict TextBox using C# to only allow numbers entry + comma(",") or dot(".") + only 2 numbers after dot or comma So this way see possible numbers that can entry:
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 个数字所以这样可以看到可以输入的可能数字：
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
Understood My goal ? I developed code bellow
明白我的目标了吗？我开发了下面的代码
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;
}
}
}
采纳答案by saeed
Try this code ! I hope this helps. Let me know if I can assist you further.
试试这个代码！我希望这有帮助。如果我能进一步帮助您，请告诉我。
This is auxiliary function i have written
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;
}
This your key press event handler
这是您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;
}
}
}
}
回答by Sergio Guillen Mantilla
I think you need something like Masked Textbox control here you have some references
我认为你需要像 Masked Textbox control 这样的东西，你有一些参考
http://msdn.microsoft.com/en-us/library/kkx4h3az.aspxhttp://www.c-sharpcorner.com/uploadfile/mahesh/maskedtextbox-in-C-Sharp/
http://msdn.microsoft.com/en-us/library/kkx4h3az.aspx http://www.c-sharpcorner.com/uploadfile/mahesh/maskedtextbox-in-C-Sharp/
Another way to do what you want is to use regular expressions
做你想做的另一种方法是使用正则表达式
回答by saeed
Well you can create a general function and call it on keypressevent this code is a general instance.
好吧，您可以创建一个通用函数并在keypress此代码是通用实例的事件时调用它。
validate_textBoxis a general function
validate_textBox是一个通用函数
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;
}
}
}
}
Then you can call function like this code for each textbox you have in the form
然后，您可以为表单中的每个文本框调用类似此代码的函数
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);
}
