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
只需使用NumericUpDown控件,并设置那些丑陋的上下按钮可见性为假。
numericUpDown1.Controls[0].Visible = false;
NumericUpDown实际上是一个包含“旋转框”(上下按钮)的控件集合,一个文本框和一些代码来验证和wange-jangle。
标记:
YourNumericUpDown.Controls[0].visible = false
将隐藏按钮,同时保持底层代码活动。
虽然不是一个明显的解决方案,但它简单而有效。. controls[1]将隐藏文本框部分,如果你想这样做的话。
其他回答
最简单粗暴的方法是使用组合框而不是带有只读的文本框。当然,只有当你希望用户使用一个合理的整数集,而不是试图接近无穷大时,它才有用。
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
这里有30多个答案,很多答案都是有用的。但我想分享system。windows。forms。textbox和system。windows。controls。textbox的通用形式。
在System.Windows.Controls.TextBox中没有可用的按键事件。 这个答案是为那些想用同样的逻辑实现System.Windows.Forms.TextBox和System.Windows.Controls.TextBox的人准备的。
这是NumberTextBox代码。对于System.Windows.Controls.TextBox,使用注释行代替之前的行。
public class NumberTextBox : System.Windows.Forms.TextBox
//public class NumberTextBox : System.Windows.Controls.TextBox
{
private double _maxValue;
private double _minValue;
private bool _flag;
private string _previousValue;
public NumberTextBox()
{
this.TextAlign = HorizontalAlignment.Right;
//TextAlignment = TextAlignment.Right;
KeyDown += TextBox_KeyDown;
TextChanged += TextBox_TextChanged;
_minValue = double.MinValue;
_maxValue = double.MaxValue;
}
private void TextBox_KeyDown(object sender, KeyEventArgs e)
{
_previousValue = this.Text;
_flag = this.SelectedText.Length > 0;
}
private void TextBox_TextChanged(object sender, EventArgs e)
//private void TextBox_TextChanged(object sender, TextChangedEventArgs e)
{
var text = this.Text;
if (text.Length < 1) return;
var cursorPosition = SelectionStart == 0 ? SelectionStart : SelectionStart - 1;
var insertedChar = text[cursorPosition];
if (IsInvalidInput(insertedChar, cursorPosition, text))
{
HandleText(text, cursorPosition);
}
ValidateRange(text, cursorPosition);
}
private bool IsInvalidInput(char insertedChar, int cursorPosition, string text)
{
return !char.IsDigit(insertedChar) && insertedChar != '.' && insertedChar != '-' ||
insertedChar == '-' && cursorPosition != 0 ||
text.Count(x => x == '.') > 1 ||
text.Count(x => x == '-') > 1;
}
private void HandleText(string text, int cursorPosition)
{
this.Text = _flag ? _previousValue : text.Remove(cursorPosition, 1);
this.SelectionStart = cursorPosition;
this.SelectionLength = 0;
}
private void ValidateRange(string text, int cursorPosition)
{
try
{
if (text == "." || _minValue < 0 && text == "-") return;
var doubleValue = Convert.ToDouble(text);
if (doubleValue > _maxValue || doubleValue < _minValue)
{
HandleText(text, cursorPosition);
}
}
catch (Exception)
{
HandleText(text, cursorPosition);
}
}
protected void SetProperties(double minValue = double.MinValue, double maxValue = double.MaxValue)
{
_minValue = minValue;
_maxValue = maxValue;
}
}
PositiveNumberTextBox代码:
public class PositiveNumberTextBox : NumberTextBox
{
public PositiveNumberTextBox()
{
SetProperties(0);
}
}
FractionNumberTextBox代码:
public class FractionNumberTextBox : NumberTextBox
{
public FractionNumberTextBox()
{
SetProperties(0, 0.999999);
}
}
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 = "";
}
}
这可能有用。它允许“真实”数值,包括正确的小数点和前面的加号或减号。从相关的KeyPress事件中调用它。
private bool IsOKForDecimalTextBox(char theCharacter, TextBox theTextBox)
{
// Only allow control characters, digits, plus and minus signs.
// Only allow ONE plus sign.
// Only allow ONE minus sign.
// Only allow the plus or minus sign as the FIRST character.
// Only allow ONE decimal point.
// Do NOT allow decimal point or digits BEFORE any plus or minus sign.
if (
!char.IsControl(theCharacter)
&& !char.IsDigit(theCharacter)
&& (theCharacter != '.')
&& (theCharacter != '-')
&& (theCharacter != '+')
)
{
// Then it is NOT a character we want allowed in the text box.
return false;
}
// Only allow one decimal point.
if (theCharacter == '.'
&& theTextBox.Text.IndexOf('.') > -1)
{
// Then there is already a decimal point in the text box.
return false;
}
// Only allow one minus sign.
if (theCharacter == '-'
&& theTextBox.Text.IndexOf('-') > -1)
{
// Then there is already a minus sign in the text box.
return false;
}
// Only allow one plus sign.
if (theCharacter == '+'
&& theTextBox.Text.IndexOf('+') > -1)
{
// Then there is already a plus sign in the text box.
return false;
}
// Only allow one plus sign OR minus sign, but not both.
if (
(
(theCharacter == '-')
|| (theCharacter == '+')
)
&&
(
(theTextBox.Text.IndexOf('-') > -1)
||
(theTextBox.Text.IndexOf('+') > -1)
)
)
{
// Then the user is trying to enter a plus or minus sign and
// there is ALREADY a plus or minus sign in the text box.
return false;
}
// Only allow a minus or plus sign at the first character position.
if (
(
(theCharacter == '-')
|| (theCharacter == '+')
)
&& theTextBox.SelectionStart != 0
)
{
// Then the user is trying to enter a minus or plus sign at some position
// OTHER than the first character position in the text box.
return false;
}
// Only allow digits and decimal point AFTER any existing plus or minus sign
if (
(
// Is digit or decimal point
char.IsDigit(theCharacter)
||
(theCharacter == '.')
)
&&
(
// A plus or minus sign EXISTS
(theTextBox.Text.IndexOf('-') > -1)
||
(theTextBox.Text.IndexOf('+') > -1)
)
&&
// Attempting to put the character at the beginning of the field.
theTextBox.SelectionStart == 0
)
{
// Then the user is trying to enter a digit or decimal point in front of a minus or plus sign.
return false;
}
// Otherwise the character is perfectly fine for a decimal value and the character
// may indeed be placed at the current insertion position.
return true;
}