Csharp 简明教程

C

类型转换是将一种数据类型转换为另一种类型。它也被称为强制类型转换。在 C# 中，类型转换有两种形式 −

Type conversion is converting one type of data to another type. It is also known as Type Casting. In C#, type casting has two forms −

Implicit type conversion − These conversions are performed by C# in a type-safe manner. For example, are conversions from smaller to larger integral types and conversions from derived classes to base classes.
Explicit type conversion − These conversions are done explicitly by users using the pre-defined functions. Explicit conversions require a cast operator.

以下示例显示了一个显式类型转换 −

The following example shows an explicit type conversion −

using System;

namespace TypeConversionApplication {
   class ExplicitConversion {
      static void Main(string[] args) {
         double d = 5673.74;
         int i;

         // cast double to int.
         i = (int)d;
         Console.WriteLine(i);
         Console.ReadKey();
      }
   }
}

编译并执行上述代码后，将产生以下结果 −

When the above code is compiled and executed, it produces the following result −

C

C# 提供以下内置类型转换方法：

C# provides the following built-in type conversion methods −

Sr.No.	Methods & Description
1	ToBoolean Converts a type to a Boolean value, where possible.
2	ToByte Converts a type to a byte.
3	ToChar Converts a type to a single Unicode character, where possible.
4	ToDateTime Converts a type (integer or string type) to date-time structures.
5	ToDecimal Converts a floating point or integer type to a decimal type.
6	ToDouble Converts a type to a double type.
7	ToInt16 Converts a type to a 16-bit integer.
8	ToInt32 Converts a type to a 32-bit integer.
9	ToInt64 Converts a type to a 64-bit integer.
10	ToSbyte Converts a type to a signed byte type.
11	ToSingle Converts a type to a small floating point number.
12	ToString Converts a type to a string.
13	ToType Converts a type to a specified type.
14	ToUInt16 Converts a type to an unsigned int type.
15	ToUInt32 Converts a type to an unsigned long type.
16	ToUInt64 Converts a type to an unsigned big integer.

以下示例将各种值类型转换为字符串类型：

The following example converts various value types to string type −

using System;

namespace TypeConversionApplication {
   class StringConversion {
      static void Main(string[] args) {
         int i = 75;
         float f = 53.005f;
         double d = 2345.7652;
         bool b = true;

         Console.WriteLine(i.ToString());
         Console.WriteLine(f.ToString());
         Console.WriteLine(d.ToString());
         Console.WriteLine(b.ToString());
         Console.ReadKey();

      }
   }
}

编译并执行上述代码后，将产生以下结果 −

When the above code is compiled and executed, it produces the following result −

75
53.005
2345.7652
True