我有一个windows窗体应用程序与一个文本框控件,我想只接受整数值。在过去,我通过重载KeyPress事件并删除不符合规范的字符来进行这种验证。我已经看了MaskedTextBox控件,但我想一个更通用的解决方案,可以与也许正则表达式,或依赖于其他控件的值。
理想情况下,按下非数字字符要么不产生结果,要么立即向用户提供关于无效字符的反馈。
我有一个windows窗体应用程序与一个文本框控件,我想只接受整数值。在过去,我通过重载KeyPress事件并删除不符合规范的字符来进行这种验证。我已经看了MaskedTextBox控件,但我想一个更通用的解决方案,可以与也许正则表达式,或依赖于其他控件的值。
理想情况下,按下非数字字符要么不产生结果,要么立即向用户提供关于无效字符的反馈。
当前回答
3解决方案
1)
//Add to the textbox's KeyPress event
//using Regex for number only textBox
private void txtBox_KeyPress(object sender, KeyPressEventArgs e)
{
if (!System.Text.RegularExpressions.Regex.IsMatch(e.KeyChar.ToString(), "\\d+"))
e.Handled = true;
}
2) 来自MSDN的另一个解决方案
// Boolean flag used to determine when a character other than a number is entered.
private bool nonNumberEntered = false;
// Handle the KeyDown event to determine the type of character entered into the control.
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
// Initialize the flag to false.
nonNumberEntered = false;
// Determine whether the keystroke is a number from the top of the keyboard.
if (e.KeyCode < Keys.D0 || e.KeyCode > Keys.D9)
{
// Determine whether the keystroke is a number from the keypad.
if (e.KeyCode < Keys.NumPad0 || e.KeyCode > Keys.NumPad9)
{
// Determine whether the keystroke is a backspace.
if (e.KeyCode != Keys.Back)
{
// A non-numerical keystroke was pressed.
// Set the flag to true and evaluate in KeyPress event.
nonNumberEntered = true;
}
}
}
}
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (nonNumberEntered == true)
{
MessageBox.Show("Please enter number only...");
e.Handled = true;
}
}
源http://msdn.microsoft.com/en-us/library/system.windows.forms.control.keypress (v =应用程序). aspx
3)使用MaskedTextBox: http://msdn.microsoft.com/en-us/library/system.windows.forms.maskedtextbox.aspx
其他回答
你可以使用TextChanged/ Keypress事件,使用正则表达式过滤数字,并采取一些行动。
在文本框中简单地使用此代码:
private void textBox1_TextChanged(object sender, EventArgs e)
{
double parsedValue;
if (!double.TryParse(textBox1.Text, out parsedValue))
{
textBox1.Text = "";
}
}
允许一行代码小数点
private void txtQty_KeyPress(object sender, KeyPressEventArgs e)
{
e.Handled = e.KeyChar != '.' && !char.IsDigit(e.KeyChar) && !char.IsControl(e.KeyChar);
}
两个选择:
Use a NumericUpDown instead. NumericUpDown does the filtering for you, which is nice. Of course it also gives your users the ability to hit the up and down arrows on the keyboard to increment and decrement the current value. Handle the appropriate keyboard events to prevent anything but numeric input. I've had success with this two event handlers on a standard TextBox: private void textBox1_KeyPress(object sender, KeyPressEventArgs e) { if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) && (e.KeyChar != '.')) { e.Handled = true; } // only allow one decimal point if ((e.KeyChar == '.') && ((sender as TextBox).Text.IndexOf('.') > -1)) { e.Handled = true; } }
您可以删除'的支票。如果你的文本框不允许小数点,'(和后续检查不止一个'.')。你也可以添加一个检查'-'如果你的文本框应该允许负值。
如果您想限制用户的位数,请使用:textBox1。MaxLength = 2;//这将允许用户只输入2位数字
这个功能包括复制粘贴,拖放,按下键,防止溢出,非常简单
public partial class IntegerBox : TextBox
{
public IntegerBox()
{
InitializeComponent();
this.Text = 0.ToString();
}
protected override void OnPaint(PaintEventArgs pe)
{
base.OnPaint(pe);
}
private String originalValue = 0.ToString();
private void Integerbox_KeyPress(object sender, KeyPressEventArgs e)
{
originalValue = this.Text;
}
private void Integerbox_TextChanged(object sender, EventArgs e)
{
try
{
if(String.IsNullOrWhiteSpace(this.Text))
{
this.Text = 0.ToString();
}
this.Text = Convert.ToInt64(this.Text.Trim()).ToString();
}
catch (System.OverflowException)
{
MessageBox.Show("Value entered is to large max value: " + Int64.MaxValue.ToString(), "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
this.Text = originalValue;
}
catch (System.FormatException)
{
this.Text = originalValue;
}
catch (System.Exception ex)
{
this.Text = originalValue;
MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK , MessageBoxIcon.Error);
}
}
}