Question

我想弄清楚如何首先选择一个对象然后我能够移动它。例如，我想首先通过触摸选择牛，然后我可以移动它。原因是当我触摸屏幕时，它正在移动牛和牛1。当我只想一次移动一头牛时。任何帮助将不胜感激。

-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

    UITouch *touch = [touches anyObject];

    CGPoint touchLocation = [touch locationInView:touch.view];

    cow.center = CGPointMake(touchLocation.x, touchLocation.y);

    cow1.center = CGPointMake(touchLocation.x, touchLocation.y);

}

Answer 1

有很多方法可以实现这类功能。这取决于您的图形的实现方式，除其他外，请查看此Apple示例代码：

http://developer.apple.com/library/ios/#samplecode/Touches/Introduction/Intro.html

Answer 2

标准解决方案是为您的两个牛对象添加单独的手势识别器，例如viewDidLoad：

UIPanGestureRecognizer *panCow1 = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(moveCow:)];
[cow1 addGestureRecognizer:panCow1];
// if non ARC, make sure to add a line that says
// [panCow1 release];

UIPanGestureRecognizer *panCow2 = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(moveCow:)];
[cow2 addGestureRecognizer:panCow2];
// if non ARC, make sure to add a line that says
// [panCow2 release];

然后你的moveCow方法看起来像：

- (void)moveCow:(UIPanGestureRecognizer *)sender
{
    if (sender.state == UIGestureRecognizerStateChanged)
    {
        CGPoint translate = [sender translationInView:self.view];

        sender.view.center = CGPointMake(sender.view.center.x + translate.x, sender.view.center.y + translate.y);
    }
}

我没有测试过这段代码，但是你明白了。这就是我通常在...周围移动单独的子视图的方式。

Answer 3

尝试使用UIPanGestureRecognizer，如下所示：

@synthesize myImage; //UIImageView

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self startMoveImage];
}

-(void) startMoveImage{
    UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];
    [self.view addGestureRecognizer:panGestureRecognizer];
}

- (void)pan:(UIPanGestureRecognizer *)gesture
{
    if ((gesture.state == UIGestureRecognizerStateChanged) ||
        (gesture.state == UIGestureRecognizerStateEnded)) {

        CGPoint position = [gesture locationInView:[myImage superview]];
        [myImage setCenter:position];
    }
}

选择图像然后移动它们

3 个答案: