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
尝试一个MaskedTextBox。它采用一种简单的掩码格式,这样你就可以将输入限制为数字或日期之类的。
其他回答
int Number;
bool isNumber;
isNumber = int32.TryPase(textbox1.text, out Number);
if (!isNumber)
{
(code if not an integer);
}
else
{
(code if an integer);
}
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);
}
}
}
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
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。
WPF的工作解决方案&一个简单的TextChangedEventArgs。
private void TextBox_TextChanged(object sender, TextChangedEventArgs e)
{
var TextBox = (sender as TextBox);
// if not a numeric value, remove news characters
if (Regex.IsMatch(TextBox.Text, "[^0-9]"))
{
foreach (TextChange Change in e.Changes)
{
TextBox.Text = TextBox.Text.Remove(Change.Offset, Change.AddedLength);
TextBox.CaretIndex = Change.Offset;
}
}
}