NSRange range=[urlStr rangeOfString:@"_content="];//筛选条件
NSString*subString = [urlStrsubstringFromIndex:range.location+range.length];//筛选特定字符串得到后面得的结果
NSRange range=[urlStr rangeOfString:@"_content="];//筛选条件
NSString*subString = [urlStrsubstringFromIndex:range.location+range.length];//筛选特定字符串得到后面得的结果