如何使textBox仅接受数字，只接受Windows 8中的一个小数点

我是Windows 8手机的新手。 我正在编写一个计算器应用程序，只能接受文本框中的数字和一个小数点。 如何阻止用户在文本框中输入两个或多个小数点，因为计算器无法处理。

我一直在使用Keydown事件，那是最好还是我应该使用Key？

private void textbox_KeyDown(object sender, System.Windows.Input.KeyEventArgs e) { } 

Answer 1

您还可以将RegExp与TextChanged事件一起使用：下面的代码段将处理任何整数和浮点数，包括正数和负数

  string previousInput = ""; private void InputTextbox_TextChanged(object sender, RoutedEventArgs e) { Regex r = new Regex("^-{0,1}\d+\.{0,1}\d*$"); // This is the main part, can be altered to match any desired form or limitations Match m = r.Match(InputTextbox.Text); if (m.Success) { previousInput = InputTextbox.Text; } else { InputTextbox.Text = previousInput; } } 

Answer 2

你可以使用这个来为你的文本框中的KeyPress事件集按键事件.Designer这样

 this.yourtextbox.KeyPress +=new System.Windows.Forms.KeyPressEventHandler(yourtextbox_KeyPress); 

然后在表单中使用它

 //only number And single decimal point input فقط عدد و یک ممیز میتوان نوشت public void onlynumwithsinglepoint(object sender, KeyPressEventArgs e) { if (!(char.IsDigit(e.KeyChar) || e.KeyChar == (char)Keys.Back || e.KeyChar == '.')) { e.Handled = true; } TextBox txtDecimal = sender as TextBox; if (e.KeyChar == '.' && txtDecimal.Text.Contains(".")) { e.Handled = true; } } 

然后

 private void yourtextbox_KeyPress(object sender, KeyPressEventArgs e) { onlynumwithsinglepoint(sender, e); } 

Answer 3

简单

 private void textBox1_KeyPress(object sender, KeyPressEventArgs e) { char ch = e.KeyChar; decimal x; if (ch == (char)Keys.Back) { e.Handled = false; } else if (!char.IsDigit(ch) && ch != '.' || !Decimal.TryParse(textBox1.Text+ch, out x) ) { e.Handled = true; } } 

Answer 4

您可以使用数字文本框或

试试这个

 private void textBox1_KeyPress(object sender, KeyPressEventArgs e) { if (Char.IsDigit(e.KeyChar) || e.KeyChar == '\b') { e.Handled = false; } else { e.Handled = true; } } 

Answer 5

对于数字==> ImputScope ="Number"您可以使用解析例子来计算字符串中的字符点，例如dat：

 char[] c = yourstring.tocharArray(); int i = 0; foreach var char in c if(char.equals(".") or char.equals(",") i++ if (i > 1) MessageBox.Show("Invalid Number") 

这段代码只是举例，但它的工作原理。

Answer 6

我曾经在.NET 2天中广泛使用它，不确定它是否仍然有效。 支持可配置的精度，货币，负数并处理所有输入方法。

 using System; using System.ComponentModel; using System.Collections; using System.Diagnostics; using System.Drawing; using System.Security.Permissions; using System.Text.RegularExpressions; using System.Windows.Forms; namespace System.Windows.Forms { public class NumericTextBox : TextBox { private System.ComponentModel.Container components = null; private bool _AllowNegatives = true; private int _Precision = 0; private char _CurrencyChar = (char)0; private bool _AutoFormat = true; private decimal _MinValue = Decimal.MinValue; private decimal _MaxValue = Decimal.MaxValue; /// 
 /// Indicates if the negative values are allowed. /// 
 [DefaultValue(true), RefreshProperties(RefreshProperties.All), Description("Indicates if the negative values are allowed."), Category("Behavior")] public bool AllowNegatives { get { return this._AllowNegatives; } set { this._AllowNegatives = value; if (!value) { if (this._MinValue < 0) this._MinValue = 0; if (this._MaxValue < 1) this._MaxValue = 1; } } } /// 
 /// Indicates the maximum number of digits allowed after a decimal point. /// 
 [DefaultValue(0), Description("Indicates the maximum number of digits allowed after a decimal point."), Category("Behavior")] public int Precision { get { return this._Precision; } set { if (value < 0) { throw new ArgumentOutOfRangeException("Precision", value.ToString(), "The value of precision must be an integer greater than or equal to 0."); } else { this._Precision = value; } } } /// 
 /// Gets or sets the character to use as a currency symbol when validating input. /// 
 [DefaultValue((char)0), Description("Gets or sets the character to use as a currency symbol when validating input."), Category("Behavior")] public char CurrencyChar { get { return this._CurrencyChar; } set { this._CurrencyChar = value; } } /// 
 /// Indicates if the text in the textbox is automatically formatted. Missing currency symbols and trailing spaces are added where applicable. /// 
 [DefaultValue(true), Description("Indicates if the text in the textbox is automatically formatted. Missing currency symbols and trailing spaces are added where applicable."), Category("Behavior")] public bool AutoFormat { get { return this._AutoFormat; } set { this._AutoFormat = value; } } /// 
 /// Gets or sets the numerical value of the textbox. /// 
 [Description("Gets or sets the numerical value of the textbox."), Category("Data")] public decimal Value { get { if (this.Text.Length == 0) { return (decimal)0; } else { return decimal.Parse(this.Text.Replace(this.CurrencyChar.ToString(), "")); } } set { if (value < 0 && !this.AllowNegatives) { throw new ArgumentException("The specified decimal is invalid, negative values are not permitted."); } this.Text = this.FormatText(value.ToString()); } } /// 
 /// Gets or sets the maximum numerical value of the textbox. /// 
 [RefreshProperties(RefreshProperties.All), Description("Gets or sets the maximum numerical value of the textbox."), Category("Behavior")] public decimal MaxValue { get { return this._MaxValue; } set { if (value <= this._MinValue) { throw new ArgumentException("The Maximum value must be greater than the minimum value.", "MaxValue"); } else { this._MaxValue = Decimal.Round(value, this.Precision); } } } /// 
 /// Gets or sets the minimum numerical value of the textbox. /// 
 [RefreshProperties(RefreshProperties.All), Description("Gets or sets the minimum numerical value of the textbox."), Category("Behavior")] public decimal MinValue { get { return this._MinValue; } set { if (value < 0 && !this.AllowNegatives) { throw new ArgumentException("The Minimum value cannot be negative when AllowNegatives is set to false.", "MinValue"); } else if (value >= this._MaxValue) { throw new ArgumentException("The Minimum value must be less than the Maximum value.", "MinValue"); } else { this._MinValue = Decimal.Round(value, this.Precision); } } } /// 
 /// Create a new instance of the NumericTextBox class with the specified container. /// 
 /// The container of the control. public NumericTextBox(System.ComponentModel.IContainer container) { /// /// Required for Windows.Forms Class Composition Designer support /// container.Add(this); InitializeComponent(); } /// 
 /// Create a new instance of the NumericTextBox class. /// 
 public NumericTextBox() { /// /// Required for Windows.Forms Class Composition Designer support /// InitializeComponent(); } #region Component Designer generated code /// 
 /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// 
 private void InitializeComponent() { // // NumericTextBox // this.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.NumericTextBox_KeyPress); this.Validating += new System.ComponentModel.CancelEventHandler(this.NumericTextBox_Validating); } #endregion /// 
 /// Checks to see if the specified text is valid for the properties selected. /// 
 /// The text to test. /// A boolean value indicating if the specified text is valid. protected bool IsValid(string text) { Regex check = new Regex("^" + ((this.AllowNegatives && this.MinValue < 0) ? (@"\-?") : "") + ((this.CurrencyChar != (char)0) ? (@"(" + Regex.Escape(this.CurrencyChar.ToString()) + ")?") : "") + @"\d*" + ((this.Precision > 0) ? (@"(\.\d{0," + this.Precision.ToString() + "})?") : "") + "$"); if (!check.IsMatch(text)) return false; if (text == "-" || text == this.CurrencyChar.ToString() || text == "-" + this.CurrencyChar.ToString()) return true; Decimal val = Decimal.Parse(text); if (val < this.MinValue) return false; if (val > this.MaxValue) return false; return true; } /// 
 /// Formats the specified text into the configured number format. /// 
 /// The text to format. /// The correctly formatted text. protected string FormatText(string text) { string format = "{0:" + this.CurrencyChar.ToString() + "0" + ((this.Precision > 0) ? "." + new String(Convert.ToChar("0"), this.Precision) : "") + ";-" + this.CurrencyChar.ToString() + "0" + ((this.Precision > 0) ? "." + new String(Convert.ToChar("0"), this.Precision) : "") + "; £0" + ((this.Precision > 0) ? "." + new String(Convert.ToChar("0"), this.Precision) : "") + "}"; return String.Format(format, text).Trim(); } /// 
 /// Overrides message handler in order to pre-process and validate pasted data. /// 
 /// Message protected override void WndProc(ref Message m) { switch (m.Msg) { case 0x0302: if (Clipboard.GetDataObject().GetDataPresent(DataFormats.Text)) { string paste = Clipboard.GetDataObject().GetData(DataFormats.Text).ToString(); string text = this.Text.Substring(0, this.SelectionStart) + paste + this.Text.Substring(this.SelectionStart + this.SelectionLength); if (this.IsValid(text)) { base.WndProc(ref m); } } break; default: base.WndProc(ref m); break; } } protected override void Dispose(bool disposing) { if( disposing ) { if(components != null) { components.Dispose(); } } base.Dispose( disposing ); } private void NumericTextBox_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) { if (Char.IsNumber(e.KeyChar) || (this.AllowNegatives && e.KeyChar == Convert.ToChar("-")) || (this.Precision > 0 && e.KeyChar == Convert.ToChar(".")) || e.KeyChar == this.CurrencyChar) { string text = this.Text.Substring(0, this.SelectionStart) + e.KeyChar.ToString() + this.Text.Substring(this.SelectionStart + this.SelectionLength); if (!this.IsValid(text)) { e.Handled = true; } } else if (!Char.IsControl(e.KeyChar)) { e.Handled = true; } } private void NumericTextBox_Validating(object sender, System.ComponentModel.CancelEventArgs e) { if (this.Text.Length == 0) { this.Text = this.FormatText("0"); } else if (this.IsValid(this.Text)) { this.Text = this.FormatText(this.Text); } else { e.Cancel = true; } } } } 

Answer 7

 private void txtDecimal_KeyPress(object sender, KeyPressEventArgs e) { if (!Char.IsDigit(e.KeyChar) && e.KeyChar != '\b' && e.KeyChar!='.') { e.Handled = true; } if (e.KeyChar == '.' && txtDecimal.Text.Contains(".")) { e.Handled = true; } } 

Answer 8

谢谢大家的帮助。 我终于做到了这一点，它在Text change事件中运行得非常好。 那是在将输入镜设置为Numbers之后

 string dika = Textbox1.Text; int countDot = 0; for (int i = 0; i < dika.Length; i++) { if (dika[i] == '.') { countDot++; if (countDot > 1) { dika = dika.Remove(i, 1); i--; countDot--; } } } Textbox1.Text = dika; Textbox1.Select(dika.Text.Length, 0); 

Answer 9

看这个。 这项工作对我而言。

  private void txtParciales_KeyDown(object sender, System.Windows.Input.KeyEventArgs e) { if (System.Text.RegularExpressions.Regex.IsMatch(txtParciales.Text, @"\d+(\.\d{2,2})")) e.Handled = true; else e.Handled = false; } 

Answer 10

 private void txtBox_KeyPress(object sender, KeyPressEventArgs e) { if (Char.IsDigit(e.KeyChar) || e.KeyChar == '\b') { // Allow Digits and BackSpace char } else if (e.KeyChar == '.' && !((TextBox)sender).Text.Contains('.')) { //Allows only one Dot Char } else { e.Handled = true; } } 

Answer 11

这是我用的。

  private void txtBoxBA_KeyDown(object sender, KeyRoutedEventArgs e) { // only allow 0-9 and "." e.Handled = !((e.Key.GetHashCode() >= 48 && e.Key.GetHashCode() <= 57)); // check if "." is already there in box. if (e.Key.GetHashCode() == 190) e.Handled = (sender as TextBox).Text.Contains("."); } 

Answer 12

尝试使用asp:RegularExpressionValidator控制器

Answer 13

  private void textBox1_KeyPress(object sender, KeyPressEventArgs e) { if (e.KeyChar != Convert.ToChar(Keys.Enter) && e.KeyChar != Convert.ToChar(Keys.Back) && e.KeyChar != Convert.ToChar(Keys.Delete) && e.KeyChar != '.' && e.KeyChar != '1' && e.KeyChar != '2' && e.KeyChar != '3' && e.KeyChar != '4' && e.KeyChar != '5' && e.KeyChar != '6' && e.KeyChar != '7' && e.KeyChar != '8' && e.KeyChar != '9' && e.KeyChar != '0') { e.Handled = true; } else { e.Handled = false; } } 

Answer 14

validation所需列表

• 停止多个点Char
• 将第一个char作为点输入停止
• 停止允许除数字和控制之外

Keypress活动

 private void txtEstimate_KeyPress(object sender, KeyPressEventArgs e) { if (e.KeyChar == '.' && txtEstimate.Text.Contains(".")) { // Stop more than one dot Char e.Handled = true; } else if (e.KeyChar == '.' && txtEstimate.Text.Length == 0) { // Stop first char as a dot input e.Handled = true; } else if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) && e.KeyChar != '.') { // Stop allow other than digit and control e.Handled = true; } } 

低于输入validation

• 0.1 – 有效
• .1 – 无效
• 12..1 – 无效
• 12.36 – 有效
• 123.2548 – 有效