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
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);
}
}
其他回答
我一直致力于一个组件的集合来完成WinForms中缺失的东西,这里是:高级表单
特别地,这是一个正则文本框类
/// <summary>Represents a Windows text box control that only allows input that matches a regular expression.</summary>
public class RegexTextBox : TextBox
{
[NonSerialized]
string lastText;
/// <summary>A regular expression governing the input allowed in this text field.</summary>
[Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
public virtual Regex Regex { get; set; }
/// <summary>A regular expression governing the input allowed in this text field.</summary>
[DefaultValue(null)]
[Category("Behavior")]
[Description("Sets the regular expression governing the input allowed for this control.")]
public virtual string RegexString {
get {
return Regex == null ? string.Empty : Regex.ToString();
}
set {
if (string.IsNullOrEmpty(value))
Regex = null;
else
Regex = new Regex(value);
}
}
protected override void OnTextChanged(EventArgs e) {
if (Regex != null && !Regex.IsMatch(Text)) {
int pos = SelectionStart - Text.Length + (lastText ?? string.Empty).Length;
Text = lastText;
SelectionStart = Math.Max(0, pos);
}
lastText = Text;
base.OnTextChanged(e);
}
}
简单地添加像myNumbericTextBox这样的东西。RegexString = "^(\\d+|)$";应该足够了。
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
我从上下文和您使用的标记假设您正在编写一个。net c#应用程序。在这种情况下,您可以订阅文本更改事件,并验证每个按键。
private void textBox1_TextChanged(object sender, EventArgs e)
{
if (System.Text.RegularExpressions.Regex.IsMatch(textBox1.Text, "[^0-9]"))
{
MessageBox.Show("Please enter only numbers.");
textBox1.Text = textBox1.Text.Remove(textBox1.Text.Length - 1);
}
}
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);
}
您可以使用TextChanged事件
private void textBox_BiggerThan_TextChanged(object sender, EventArgs e)
{
long a;
if (! long.TryParse(textBox_BiggerThan.Text, out a))
{
// If not int clear textbox text or Undo() last operation
textBox_LessThan.Clear();
}
}