C#字符串截取函数

一个简单的字符串截取函数，可以指定截取位数，例如：输入(“This is way too long”, 11, “…”) 返回为 “This is way…”

public static string Truncate(this string myString, int limit, string symbol)
{
    if (myString == null)
        return null;
 
    if (limit < 0)
        throw new ArgumentOutOfRangeException("limit", limit, "must be 0 or greater");
 
    if (symbol == null)
        throw new ArgumentNullException("symbol must not be null");
 
    if (myString.Length < limit)
        return myString;
 
    return myString.Substring(0, limit) + symbol;
}