输入一个字符串转换为长型整数输出

C# code as below:

public static long ConvertStringToLong(string str)

{

str = str.Trim();

long m = 0;

int l = 1;

int startIndex = 0;

if (str[0] == '-')

{

l = -1;

startIndex++;

}

for (int i = startIndex; i < str.Length; i++)

{

m *= 10;

m += str[i];

}

return m * l;

}