＊＊＊＊简单正则表达式＊＊＊＊＊

Question

string url = "http://pic.aa.com/bb/200812/20081217174617355.jpg";
  
若结尾是jpg或JPG,则变成"http://pic.aa.com/bb/200812/20081217174617355_sml.jpg";
            若是gif,则变成"http://pic.aa.com/bb/200812/20081217174617355_sml.gif";
            若是png,则变成"http://pic.aa.com/bb/200812/20081217174617355_sml.png";
            要求用正则

Answer 1

string url = "http://pic.aa.com/bb/200812/20081217174617355.jpg";
int count = url.IndexOf(".jpg");
url = url.Substring(0, count) + "_sml" + ".jpg";
Console.WriteLine(url);

Answer 2

要求用正则.string url = "http://pic.aa.com/bb/200812/20081217174617355.jpg";
int count = url.IndexOf(".jpg");
url = url.Substring(0, count) + "_sml" + ".jpg";
Console.WriteLine(url);int count = url.IndexOf(".gif");
url = url.Substring(0, count) + "_sml" + ".gif";
Console.WriteLine(url);......
上面的写法都会

Answer 3

唉。string url = "http://pic.aa.com/bb/200812/20081217174617355.jpg";
url = Regex.Replace(url,@"(?i)\.jpg","_sml$0");
Console.WriteLine(url);

Answer 4

注:string url = "http://pic.aa.com/bb/200812/20081217174617355.jpg"; 由于允许上传的图片类型很多,结属的扩展名不确定，可能是png,可能是PNG,可能是gif，可能是bmp，所以用正则匹配会更好一些.

Answer 5

全的string url = "http://pic.aa.com/bb/200812/20081217174617355.GIF";
url = Regex.Replace(url,@"(?i)\.(jpg|jpeg|gif|png)","_sml$0");
Console.WriteLine(url);

Answer 6

//楼主是不是想将图片的名字中的非数字的字符去掉阿？
string str = "http://pic.aa.com/bb/200812/20081217174617355_sml.jpg";
string output = Regex.Replace(str,@"(?i)[^\d]+(?=\.(jpg|gif|png))","");