C# Convert类简介

Convert类是将一个基本数据类型转换为另一个基本数据类型。

例如如下的代码就行不通了：

我们把上面的代码稍稍修改就可以达到目的了

下面的代码示例演示 Convert 类中的一些转换方法，包括 ToInt32、ToBoolean 和 ToString。

            double dNumber = 23.15;

            try {
                // Returns 23
                int    iNumber = System.Convert.ToInt32(dNumber);
            }
            catch (System.OverflowException) {
                System.Console.WriteLine(
                            "Overflow in double to int conversion.");
            }
            // Returns True
            bool   bNumber = System.Convert.ToBoolean(dNumber);
            
            // Returns "23.15"
            string strNumber = System.Convert.ToString(dNumber);

            try {
                // Returns '2'
                char chrNumber = System.Convert.ToChar(strNumber[0]);
            } 
            catch (System.ArgumentNullException) {
                System.Console.WriteLine("String is null");
            }
            catch (System.FormatException) {
                System.Console.WriteLine("String length is greater than 1.");
            }

            // System.Console.ReadLine() returns a string and it
            // must be converted.
            int newInteger = 0;
            try {
                System.Console.WriteLine("Enter an integer:");
                newInteger = System.Convert.ToInt32(
                                    System.Console.ReadLine());
            }
            catch (System.ArgumentNullException) {
                System.Console.WriteLine("String is null.");
            }
            catch (System.FormatException) {
                System.Console.WriteLine("String does not consist of an " +
                                "optional sign followed by a series of digits.");
            } 
            catch (System.OverflowException) {
                System.Console.WriteLine(
                "Overflow in string to int conversion.");
            }

            System.Console.WriteLine("Your integer as a double is {0}",
                                     System.Convert.ToDouble(newInteger));