NSString的trim方法

NSString *trimmedString = [_base64String stringByTrimmingCharactersInSet:

[NSCharacterSet whitespaceAndNewlineCharacterSet]];

//完整寫法
NSMutableCharacterSet *set = [[NSMutableCharacterSet alloc] init];
            [set addCharactersInString:@"{"];
            [set addCharactersInString:@"("];
            [set addCharactersInString:@"}"];
            [set addCharactersInString:@")"];
            [set formUnionWithCharacterSet:[NSCharacterSet newlineCharacterSet]];

            

            cell.textLabel.text = [text stringByTrimmingCharactersInSet:set];;