string st="GT123_1";

string[] sArray=st.split("_");

//即可得到sArray[0]="GT123",sArray[1]="1";

string str = "GTAZB_JiangjBen_123";

string[] sArray = str.Split(new char[] { 'j', '_' });

foreach(string e in sArray)

{

  Console.WriteLine(e);

}

//得到sArray[]="GTAZB",sArray[]="Jiang",sArray[]="Ben",sArray[]="";

string str = "GTAZB_JiangjBen_123";

string[] sArray = str.Split( new string[]{"Ji","jB"}, StringSplitOptions.RemoveEmptyEntries);

foreach(string e in sArray)

{

  Console.WriteLine(e);

}

//得到sArray[]="GTAZB_",sArray[]="ang",sArray[]="en_123";

string str = "GTAZB_JiangjBen_123";

int start=,length=;

Console.WriteLine(str.Substring(start-, length));

//输出得到AZB_Jian。

string str = "GTAZB_JiangjBen_123";

string tSt;

int i=;

tSt = str.Substring(str.Length - i);

Console.WriteLine(tSt);

//输出n_123

string str = "GTAZB_JiangjBen_123";

string tSt;

tSt = str.Replace("","");

Console.WriteLine(tSt);

//输出GTAZB_JiangjBen_321

string str = "GTAZB_JiangjBen_123";

string tSt;

tSt = str.Replace("Jiangj","");

Console.WriteLine(tSt);

//输出GTAZB_Ben_123

 string str = "GTAZB_JiangjBen_123";

int i=,length=;

str=str.remove(i,length);

console.writeline(str);

//输出GTAZBen_123