c#翻倍.在紧凑框架上的TryParse等价

本文关键字:TryParse 等价 框架 翻倍 | 更新日期: 2023-09-27 18:15:28

我们想在Win CE 5.0驱动的设备上实现一个只输入货币的文本框(###.00)。该应用程序正在使用。net Compact Framework 3.5 (c#)开发。

有人向我建议以下解决方案:

    private void textbox1_KeyDown(object sender, KeyEventArgs e)
    {
        double amount = 0.0d;
        if (double.TryParse(txtbox1.Text, NumberStyles.Currency, null, out amount))
        {
            textbox.Text = amount.ToString("C");
        }
    }

(Decimal.TryParse不支持紧凑框架)?

c#翻倍.在紧凑框架上的TryParse等价

紧凑框架不支持TryParse。

可以替换为:

    private void textbox1_KeyDown(object sender, KeyEventArgs e)
    {
        double amount = 0.0d;
        try
        {
            amount = Convert.ToDouble(txtbox1.Text);
            textbox.Text = amount.ToString("C");
        }
        catch
        {
        }          
    }

或者参考这个博客来了解Compact Framework的TryParse实现:https://web.archive.org/web/20160606182643/http://www.yortondotnet.com/2009/11/tryparse-for-compact-framework.html

Compact Framework的TryParse

/// <summary>
/// Contains methods to assist with parsing one value into another.
/// </summary>
public static class ParseAssistant
{
  #region TryParse Overloads
  /// <summary>
  /// Attempts to parse the string provided into an integer value. 
  /// </summary>
  /// <remarks>Returns 0 in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or zero if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out int result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = Convert.ToInt32(s);
            retVal = true;
        }
        catch (FormatException) { result = 0; }
        catch (InvalidCastException) { result = 0; }
#else
    retVal = int.TryParse(s, out result);
#endif
    return retVal;
  }
  /// <summary>
  /// Attempts to parse the string provided into a byte value. 
  /// </summary>
  /// <remarks>Returns 0 in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or zero if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out byte result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = Convert.ToByte(s);
            retVal = true;
        }
        catch (FormatException) { result = 0; }
        catch (InvalidCastException) { result = 0; }
#else
    retVal = byte.TryParse(s, out result);
#endif
    return retVal;
  }
  /// <summary>
  /// Attempts to parse the string provided into an Int16 value. 
  /// </summary>
  /// <remarks>Returns 0 in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or zero if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out Int16 result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = Convert.ToInt16(s);
            retVal = true;
        }
        catch (FormatException) { result = 0; }
        catch (InvalidCastException) { result = 0; }
#else
    retVal = Int16.TryParse(s, out result);
#endif
    return retVal;
  }
  /// <summary>
  /// Attempts to parse the string provided into an Int64 value. 
  /// </summary>
  /// <remarks>Returns 0 in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or zero if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out Int64 result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = Convert.ToInt64(s);
            retVal = true;
        }
        catch (FormatException) { result = 0; }
        catch (InvalidCastException) { result = 0; }
#else
    retVal = Int64.TryParse(s, out result);
#endif
    return retVal;
  }
  /// <summary>
  /// Attempts to parse the string provided into a decimal value. 
  /// </summary>
  /// <remarks>Returns 0 in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or zero if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out decimal result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = Convert.ToDecimal(s);
            retVal = true;
        }
        catch (FormatException) { result = 0; }
        catch (InvalidCastException) { result = 0; }
#else
    retVal = decimal.TryParse(s, out result);
#endif
    return retVal;
  }
  /// <summary>
  /// Attempts to parse the string provided into a float value. 
  /// </summary>
  /// <remarks>Returns 0 in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or zero if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out float result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = (float)Convert.ToDecimal(s);
            retVal = true;
        }
        catch (FormatException) { result = 0; }
        catch (InvalidCastException) { result = 0; }
#else
    retVal = float.TryParse(s, out result);
#endif
    return retVal;
  }
  /// <summary>
  /// Attempts to parse the string provided into a double value. 
  /// </summary>
  /// <remarks>Returns 0 in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or zero if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out double result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = Convert.ToDouble(s);
            retVal = true;
        }
        catch (FormatException) { result = 0; }
        catch (InvalidCastException) { result = 0; }
#else
    retVal = double.TryParse(s, out result);
#endif
    return retVal;
  }
  /// <summary>
  /// Attempts to parse the string provided into an sbyte value. 
  /// </summary>
  /// <remarks>Returns 0 in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or zero if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out sbyte result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = (sbyte)Convert.ToInt32(s);
            retVal = true;
        }
        catch (FormatException) { result = 0; }
        catch (InvalidCastException) { result = 0; }
#else
    retVal = sbyte.TryParse(s, out result);
#endif
    return retVal;
  }
  /// <summary>
  /// Attempts to parse the string provided into a uint value. 
  /// </summary>
  /// <remarks>Returns 0 in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or zero if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out uint result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = (uint)Convert.ToUInt64(s);
            retVal = true;
        }
        catch (FormatException) { result = 0; }
        catch (InvalidCastException) { result = 0; }
#else
    retVal = uint.TryParse(s, out result);
#endif
    return retVal;
  }
  /// <summary>
  /// Attempts to parse the string provided into a ulong value. 
  /// </summary>
  /// <remarks>Returns 0 in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or zero if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out ulong result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = (ulong)Convert.ToUInt64(s);
            retVal = true;
        }
        catch (FormatException) { result = 0; }
        catch (InvalidCastException) { result = 0; }
#else
    retVal = ulong.TryParse(s, out result);
#endif
    return retVal;
  }
  /// <summary>
  /// Attempts to parse the string provided into a ushort value. 
  /// </summary>
  /// <remarks>Returns 0 in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or zero if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out ushort result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = (ushort)Convert.ToUInt64(s);
            retVal = true;
        }
        catch (FormatException) { result = 0; }
        catch (InvalidCastException) { result = 0; }
#else
    retVal = ushort.TryParse(s, out result);
#endif
    return retVal;
  }
  /// <summary>
  /// Attempts to parse the string provided into an <see cref="System.DateTime"/> value. 
  /// </summary>
  /// <remarks>Returns <see cref="System.DateTime.MinValue"/> in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or <see cref="System.DateTime.MinValue"/> if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out DateTime result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = Convert.ToDateTime(s);
            retVal = true;
        }
        catch (FormatException) { result = DateTime.MinValue; }
        catch (InvalidCastException) { result = DateTime.MinValue; }
#else
    retVal = DateTime.TryParse(s, out result);
#endif
    return retVal;
  }
  /// <summary>
  /// Attempts to parse the string provided into an integer value. 
  /// </summary>
  /// <remarks>Returns false in the result parameter if the parse fails.</remarks>
  /// <param name="s">The string to attempt to parse.</param>
  /// <param name="result">The result of the parsed string, or false if parsing failed.</param>
  /// <returns>A boolean value indicating whether or not the parse succeeded.</returns>
  [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "s")]
  public static bool TryParse(string s, out bool result)
  {
    bool retVal = false;
#if WindowsCE
        try
        {
            result = Convert.ToBoolean(s);
            retVal = true;
        }
        catch (FormatException) { result = false; }
        catch (InvalidCastException) { result = false; }
#else
    retVal = bool.TryParse(s, out result);
#endif
    return retVal;
  }
  #endregion
}

https://web.archive.org/web/20160606182643/http://www.yortondotnet.com/2009/11/tryparse-for-compact-framework.html