@property (weak, nonatomic) IBOutlet UITextField *Text1;

@property (weak, nonatomic) IBOutlet UITextField *Text2;

@property (weak, nonatomic) IBOutlet UILabel *result;

- (IBAction)GetResult:(id)sender {

    NSString * t1 = [_Text1 text];

    NSString * t2 = [_Text2 text];

    NSInteger tt1 = [t1 integerValue];//将指针转换成long型

    NSInteger tt2 = [t2 integerValue];

    NSInteger a = tt1 +tt2;

    [_result setText:[NSString stringWithFormat:@"%ld",a]];  //在_result中显示结果 

    [self.view endEditing:YES];//关闭键盘

}

最简答的加法计算器 关闭键盘的方法 [_result setText:[NSString stringWithFormat:@"%ld",a]];