方法一：
///<summary>
///字符串重复N遍
///</summary>
///<param name="str"></param>
///<param name="n"></param>
///<returns></returns>
///<example>
///<![CDATA[Console.WriteLine(RepeatString("H", 5));]]>
///</example>
public static string RepeatString(string str, int n)
{
char[] arr = str.ToCharArray();
char[] arrDest = new char[arr.Length * n];
for (int i = 0; i < n; i++)
{
Buffer.BlockCopy(arr, 0, arrDest, i * arr.Length * 2, arr.Length * 2);
}
return new string(arrDest);
}
方法二：
///<summary>
///使用范型,重复N遍
///</summary>
///<param name="str">泛型参数,根据传入的参数判断是什么类型</param>
///<param name="n"></param>
///<returns></returns>
///<example>
///<![CDATA[
/// Console.WriteLine(RepeatStringByGeneric(54, 10));
/// Console.WriteLine(RepeatStringByGeneric("abc", 10));
/// ]]>
///</example>
public static string RepeatStringByGeneric<T>(T str, int n)//泛型方法
{
string s = str.ToString();
char[] arr = s.ToCharArray();
char[] arrDest = new char[arr.Length * n];
for (int i = 0; i < n; i++)
{
Buffer.BlockCopy(arr, 0, arrDest, i * arr.Length * 2, arr.Length * 2);
}
return new string(arrDest);
}
方法三：(本方法只适用于重复单一字符)
string str = new string('A',100);//注意:new string实例化的是char类型,100是长度
Console.WriteLine(str);
测试环境：VS2008 ENU
