Question

当我拖动uiimageview时，中心位于点击位置。我正在使用以下代码

imageView.center=[[touches anyObject] locationInView:self.view];

所以即使我在角落拖动鼠标也会跳到图像中心。

如何让鼠标定位在imageview的点击位置。???

提前完成

Answer 1

我想你想要移动你的imageView并且imageView正在“无心地”将它的中心移动到你的接触点......

如果您不希望imageView在触摸时设置其中心，但是从用户触摸的任何点拖动它，跟踪他触摸的第一个CGPoint，然后重新定位图像在前两个接触点之间的相对距离

@interface myViewController : UIViewController {
    CGPoint touchPoint;
    BOOL touchedInside;
}
@end

@implementation myViewController

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    touchPoint = [touch locationInView:self.view];
    CGPoint pointInside = [touch locationInView:imageView];
    if ([imageView pointInside:pointInside withEvent:event])
        touchedInside = YES;
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    if (touchedInside) {
        UITouch *touch = [touches anyObject];
        CGPoint newPoint = [touch locationInView:self.view];  // get the new touch location
        imageView.center = CGPointMake(imageView.center.x + newPoint.x - touchPoint.x, imageView.center.y + newPoint.y - touchPoint.y); // add the relative distances to the imageView.center
        touchPoint = newPoint;  // assign the newest touch location to the old one
    }
}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
    touchedInside = NO;
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    if (touchedInside) {
        UITouch *touch = [touches anyObject];
        CGPoint newPoint = [touch locationInView:self.view];

        imageView.center = CGPointMake(imageView.center.x + newPoint.x - touchPoint.x, imageView.center.y + newPoint.y - touchPoint.y);
    }   
    touchedInside = NO;
}

@end

如何让鼠标定位在imageview的点击位置。

1 个答案: