IOS手指辨識基本實作(三)

實作一個辨識手指滑動的起始點到終點的位置點

1. 新開一個專案

 

2. 在ViewController上放置三個Label

3. 將這些Label註冊到myTouchViewController.h(從Storyboard 的Label拖拉到檔案上)

#import <UIKit/UIKit.h>

@interface myTouchViewController : UIViewController
@property (weak, nonatomic) IBOutlet UILabel *startPointLabel;
@property (weak, nonatomic) IBOutlet UILabel *movePointLabel;
@property (weak, nonatomic) IBOutlet UILabel *endPointLabel;

@end

4. 在myTouchViewController.m上加入所需程式碼如下，分別顯示手指滑動的起始點等。

- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    CGPoint point = [[touches anyObject] locationInView:self.view];
    startPointLabel.text = [NSString stringWithFormat:@"起點 x= %3.2f, y= %3.2f", point.x, point.y];
   
}

- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    CGPoint point = [[touches anyObject] locationInView:self.view];
    movePointLabel.text = [NSString stringWithFormat:@"現在點 x= %3.2f, y= %3.2f", point.x, point.y];
}


- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    CGPoint point = [[touches anyObject] locationInView:self.view];
    endPointLabel.text = [NSString stringWithFormat:@"終點 x = %3.2f, y= %3.2f", point.x , point.y];
}

5. 完成後顯示結果如下