Export (0) Print
Expand All

Convert.ToUInt16 Method (Object, IFormatProvider)

Converts the value of the specified object to a 16-bit unsigned integer, using the specified culture-specific formatting information.

This API is not CLS-compliant. 

Namespace:  System
Assemblies:   System.Runtime.Extensions (in System.Runtime.Extensions.dll)
  mscorlib (in mscorlib.dll)

[CLSCompliantAttribute(false)]
public static ushort ToUInt16(
	Object value,
	IFormatProvider provider
)

Parameters

value
Type: System.Object

An object that implements the IConvertible interface.

provider
Type: System.IFormatProvider

An object that supplies culture-specific formatting information.

Return Value

Type: System.UInt16
A 16-bit unsigned integer that is equivalent to value, or zero if value is null.

ExceptionCondition
FormatException

value is not in an appropriate format.

InvalidCastException

value does not implement the IConvertible interface.

-or-

The conversion is not supported.

OverflowException

value represents a number that is less than UInt16.MinValue or greater than UInt16.MaxValue.

The return value is the result of invoking the IConvertible.ToUInt16 method of the underlying type of value.

provider enables the user to specify culture-specific conversion information about the contents of value. For example, if value is a String that represents a number, provider could supply culture-specific information about the notation used to represent that number.

The base types ignore provider; however, the parameter may be used if value is a user-defined type that implements the IConvertible interface.

The following example defines a HexString class that implements the IConvertible interface and that is designed to hold the string representation of both 16-bit signed and 16-bit unsigned values. The class includes a Sign property that indicates the sign of its hexadecimal value.

using System;
using System.Globalization;
using System.Text.RegularExpressions;

public enum SignBit { Negative=-1, Zero=0, Positive=1 };

public struct HexString : IConvertible
{
   private SignBit signBit;
   private string hexString;

   public SignBit Sign
   { 
      set { signBit = value; }
      get { return signBit; }
   }

   public string Value
   { 
      set {
         if (value.Trim().Length > 4)
            throw new ArgumentException("The string representation of a 160bit integer cannot have more than four characters.");
         else if (! Regex.IsMatch(value, "([0-9,A-F]){1,4}", RegexOptions.IgnoreCase))
            throw new ArgumentException("The hexadecimal representation of a 16-bit integer contains invalid characters.");
         else
            hexString = value;
      }
      get { return hexString; }
   }

   // IConvertible implementations. 
   public TypeCode GetTypeCode() {
      return TypeCode.Object;
   }

   public bool ToBoolean(IFormatProvider provider)
   {
      return signBit != SignBit.Zero;
   } 

   public byte ToByte(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         throw new OverflowException(String.Format("{0} is out of range of the Byte type.", Convert.ToInt16(hexString, 16)));
      else 
         try {
            return Convert.ToByte(UInt16.Parse(hexString, NumberStyles.HexNumber));
         }
         catch (OverflowException e) {
            throw new OverflowException(String.Format("{0} is out of range of the UInt16 type.", Convert.ToUInt16(hexString, 16)), e);
         }
   }

   public char ToChar(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative) { 
         throw new OverflowException(String.Format("{0} is out of range of the Char type.", Convert.ToInt16(hexString, 16)));
      }

      UInt16 codePoint = UInt16.Parse(this.hexString, NumberStyles.HexNumber);
      return Convert.ToChar(codePoint);
   } 

   public DateTime ToDateTime(IFormatProvider provider)
   {
      throw new InvalidCastException("Hexadecimal to DateTime conversion is not supported.");
   }

   public decimal ToDecimal(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative) 
      {
         short hexValue = Int16.Parse(hexString, NumberStyles.HexNumber);
         return Convert.ToDecimal(hexValue);
      }
      else 
      {
         ushort hexValue = UInt16.Parse(hexString, NumberStyles.HexNumber);
         return Convert.ToDecimal(hexValue);
      }
   }

   public double ToDouble(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToDouble(Int16.Parse(hexString, NumberStyles.HexNumber));
      else 
         return Convert.ToDouble(UInt16.Parse(hexString, NumberStyles.HexNumber));
   }   

   public short ToInt16(IFormatProvider provider) 
   {
      if (signBit == SignBit.Negative)
         return Int16.Parse(hexString, NumberStyles.HexNumber);
      else 
         try {
            return Convert.ToInt16(UInt16.Parse(hexString, NumberStyles.HexNumber));
         }
         catch (OverflowException e) {
            throw new OverflowException(String.Format("{0} is out of range of the Int16 type.", 
                                                      Convert.ToUInt16(hexString, 16)), e);
         }
   }

   public int ToInt32(IFormatProvider provider) 
   {
      if (signBit == SignBit.Negative)
         return Convert.ToInt32(Int16.Parse(hexString, NumberStyles.HexNumber));
      else 
         return Convert.ToInt32(UInt16.Parse(hexString, NumberStyles.HexNumber));
   }

   public long ToInt64(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToInt64(Int16.Parse(hexString, NumberStyles.HexNumber));
      else 
         return Int64.Parse(hexString, NumberStyles.HexNumber);
   }

   public sbyte ToSByte(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         try {
            return Convert.ToSByte(Int16.Parse(hexString, NumberStyles.HexNumber));
         }
         catch (OverflowException e) {
            throw new OverflowException(String.Format("{0} is outside the range of the SByte type.", 
                                                      Int16.Parse(hexString, NumberStyles.HexNumber), e));
         }
      else 
         try {
            return Convert.ToSByte(UInt16.Parse(hexString, NumberStyles.HexNumber));
         }   
         catch (OverflowException e) {
            throw new OverflowException(String.Format("{0} is outside the range of the SByte type.", 
                                                   UInt16.Parse(hexString, NumberStyles.HexNumber)), e);
         } 
   }

   public float ToSingle(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         return Convert.ToSingle(Int16.Parse(hexString, NumberStyles.HexNumber));
      else 
         return Convert.ToSingle(UInt16.Parse(hexString, NumberStyles.HexNumber));
   }

   public string ToString(IFormatProvider provider)
   {
      return "0x" + this.hexString;
   }

   public object ToType(Type conversionType, IFormatProvider provider)
   {
      switch (Type.GetTypeCode(conversionType))
      {
         case TypeCode.Boolean: 
            return this.ToBoolean(null);
         case TypeCode.Byte:
            return this.ToByte(null);
         case TypeCode.Char:
            return this.ToChar(null);
         case TypeCode.DateTime:
            return this.ToDateTime(null);
         case TypeCode.Decimal:
            return this.ToDecimal(null);
         case TypeCode.Double:
            return this.ToDouble(null);
         case TypeCode.Int16:
            return this.ToInt16(null);
         case TypeCode.Int32:
            return this.ToInt32(null);
         case TypeCode.Int64:
            return this.ToInt64(null);
         case TypeCode.Object:
            if (typeof(HexString).Equals(conversionType))
               return this;
            else 
               throw new InvalidCastException(String.Format("Conversion to a {0} is not supported.", conversionType.Name));
         case TypeCode.SByte:
            return this.ToSByte(null);
         case TypeCode.Single:
            return this.ToSingle(null);
         case TypeCode.String:
            return this.ToString(null);
         case TypeCode.UInt16:
            return this.ToUInt16(null);
         case TypeCode.UInt32:
            return this.ToUInt32(null);
         case TypeCode.UInt64:
            return this.ToUInt64(null);   
         default:
            throw new InvalidCastException(String.Format("Conversion to {0} is not supported.", conversionType.Name));   
      }
   }

   public UInt16 ToUInt16(IFormatProvider provider) 
   {
      if (signBit == SignBit.Negative)
         throw new OverflowException(String.Format("{0} is outside the range of the UInt16 type.", 
                                                   Int16.Parse(hexString, NumberStyles.HexNumber)));
      else 
         return UInt16.Parse(hexString, NumberStyles.HexNumber);
   }

   public UInt32 ToUInt32(IFormatProvider provider)
   {
      if (signBit == SignBit.Negative)
         throw new OverflowException(String.Format("{0} is outside the range of the UInt32 type.", 
                                                   Int16.Parse(hexString, NumberStyles.HexNumber)));
      else 
         return Convert.ToUInt32(hexString, 16);
   }

   public UInt64 ToUInt64(IFormatProvider provider) 
   {
      if (signBit == SignBit.Negative)
         throw new OverflowException(String.Format("{0} is outside the range of the UInt64 type.", 
                                                   Int64.Parse(hexString, NumberStyles.HexNumber)));
      else 
         return Convert.ToUInt64(hexString, 16);
   }
}

The following example shows that a call to the ToUInt16(Object, IFormatProvider) method that passes a HexString object as a parameter, in turn, calls the IConvertible.ToUInt16 implementation of the HexString class.

public class Example
{
   public static void Main()
   {
      ushort positiveValue = 32000;
      short negativeValue = -1;

      HexString positiveString = new HexString();
      positiveString.Sign = (SignBit) Math.Sign(positiveValue);
      positiveString.Value = positiveValue.ToString("X2");

      HexString negativeString = new HexString();
      negativeString.Sign = (SignBit) Math.Sign(negativeValue);
      negativeString.Value = negativeValue.ToString("X2");

      try {
         Console.WriteLine("0x{0} converts to {1}.", positiveString.Value, Convert.ToUInt16(positiveString));
      }
      catch (OverflowException) {
         Console.WriteLine("{0} is outside the range of the UInt16 type.", 
                           Int16.Parse(negativeString.Value, NumberStyles.HexNumber));
      }

      try {
         Console.WriteLine("0x{0} converts to {1}.", negativeString.Value, Convert.ToUInt16(negativeString));
      }
      catch (OverflowException) {
         Console.WriteLine("{0} is outside the range of the UInt16 type.", 
                           Int16.Parse(negativeString.Value, NumberStyles.HexNumber));
      }   
   }
}
// The example displays the following output: 
//       0x7D00 converts to 32000. 
//       -1 is outside the range of the UInt16 type.

.NET Framework

Supported in: 4.6, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Show:
© 2014 Microsoft