{
//保存前一次點擊的座標
CGPoint _prePoint;
}
- (void)createImageView
{
UIImageView *imageView = [[UIImageView alloc] init];
imageView.frame = CGRectMake(30, 50, 300, 400);
imageView.image = [UIImage imageNamed:@"17_5.jpg"];
imageView.tag = 100;
[self.view addSubview:imageView];
}
//UIEvent代表一個事件 ， UITouch代表了一個觸摸，一個事件中，可能由多個觸摸對象
//UIEvent是系統捕獲併發送給應用程序，經過hittest測試確定該事件發生在那個控件上。
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
//保存第一點的位置
UITouch *touch = [touches anyObject];
//1. 保存起始點座標
_prePoint = [touch locationInView:self.view];
}
//2.2觸摸移動事件
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
//2. 取到觸摸當前點得座標
CGPoint curPoint = [touch locationInView:self.view];
//3. 計算兩個點之間的偏移量
CGPoint trans = CGPointMake(curPoint.x - _prePoint.x, curPoint.y - _prePoint.y);
//4. 根據計算的偏移量移動 imageview;
UIImageView *imageView = (id)[self.view viewWithTag:100];
imageView.center = CGPointMake(imageView.center.x + trans.x, imageView.center.y + trans.y);
//5. 設置之前點得座標爲當前觸摸的座標
_prePoint = curPoint;
}
//3.觸摸響應事件調用方法
//單擊放大圖片爲全屏
- (void)tapOnce
{
UIImageView *imageView = (id)[self.view viewWithTag:100];
imageView.frame = self.view.bounds;
}
- (void)tapTwice
{
UIImageView *imageView = (id)[self.view viewWithTag:100];
imageView.frame = CGRectMake(30, 50, 300, 400);
}