//Nstring字符串 除出space 和tab键字符
NSString *searchText = @"我有1个 梦想";
NSString *textStr = [searchText stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
//将字符串转换成字符串数组
NSArray *arr = [searchText componentsSeparatedByCharactersInSet: [NSCharacterSet whitespaceCharacterSet]];
//NSString字符串截取的方法
NSString *name = @"http://127.0.0.1:8080/webbase/news/2012/2/14/123.jpg";
NSRange range = [name rangeOfString: @"/" options: NSBackwardsSearch];
name = [name substringFromIndex: range.location];
name = @"123.jpg";