如何使用touchesMove UIViewMoved具有仿射變換

Question

我有UIView通過使用垂直轉換

currentView.layer.affineTransform = CATransform3DGetAffineTransform(CATransform3DConcat(currentView.layer.transform,CATransform3DMakeRotation(M_PI, 1.0, 0.0, 0.0f)));

現在，我需要通過觸摸將該UIView從一個位置移動到另一個位置，為此我已經使用了

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

}

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

}

但是我無法維持這種轉變，我們如何實現這一目標？

基本上我使用以下調用在UIView上添加了一些UI元素

-(void)AddItemOnView:(UIView*)aView
               Angle:(CGFloat)aDegree
             XOrigin:(CGFloat)aXOrigin
             YOrigin:(CGFloat)aYOrigin
               Width:(CGFloat)aWidth
              Height:(CGFloat)aHeight
               FlipX:(CGFloat)aFlipHorrizontal
               FlipY:(CGFloat)aFlipVerticle
{
    UIView* currentView = aView;
    if(currentView)
    {
        CGFloat angle = aDegree;
        CGFloat flipHorrizontal = aFlipHorrizontal;
        CGFloat flipVerticle = aFlipVerticle;
        CGFloat xOrigin = aXOrigin;
        CGFloat yOrigin = aYOrigin;
        CGFloat width = aWidth;
        CGFloat height = aHeight;

        currentView.layer.anchorPoint = CGPointMake(0.0f, 0.0f);
        currentView.frame = CGRectIntegral(CGRectMake(0, 0, width, height));

        /* Flip The View Horrizontly*/
        if(flipHorrizontal < 0)
        {
            /* Concat With previous Layer Operation */

            currentView.layer.affineTransform = CATransform3DGetAffineTransform(CATransform3DConcat(currentView.layer.transform,CATransform3DMakeRotation(M_PI, 0.0, 1.0, 0.0f)));

            /* Need to set anchor point ==> Top Right Corner */
            currentView.layer.anchorPoint = CGPointMake(1.0f, 0.0f);

        }

        /* Flip The View Verticaly*/
        if(flipVerticle < 0)
        {
            /* Concat With previous Layer Operation */

            currentView.layer.affineTransform = CATransform3DGetAffineTransform(CATransform3DConcat(currentView.layer.transform,CATransform3DMakeRotation(M_PI, 1.0, 0.0, 0.0f)));

            if(flipHorrizontal < 0)
            {
                /* This needs to set as we have already done flip X */

                /* Need to set anchor point ==> Bottom Right Corner */
                currentView.layer.anchorPoint = CGPointMake(1.0f, 1.0f);
            }
            else
            {
                /* Need to set anchor point ==> Bottom Left Corner */
                currentView.layer.anchorPoint = CGPointMake(0.0f, 1.0f);
            }

        }

        /* Perform Rotation */
        if(angle != 0)
        {
            /* Concat With previous Layer Operation */

            currentView.layer.affineTransform = CATransform3DGetAffineTransform(CATransform3DConcat(currentView.layer.transform,CATransform3DMakeRotation(DegreesToRadians(angle), 0, 0, 1.0)));

            if(flipHorrizontal < 0 || flipVerticle < 0)
            {
                /* Countinue with previous anchor point */
            }
            else
            {
                /* Need to set anchor point ==> Top Left Corner */
                currentView.layer.anchorPoint = CGPointMake(0.0f, 0.0f);
            }

        }

        /* Set Origins of View */
        currentView.layer.position = CGPointMake(xOrigin, yOrigin);
        [self addSubview:currentView];
    }

}

現在，我正在尋找移動具有變換的這些添加的UIViews。

Answer 1

我不確定您所說的“我無法保持轉換”是什么意思，不過，我認為這可能會有所幫助。

對於初學者，當您將視圖應用於“ Identity”變換之外的其他變換時， frame屬性將變得毫無意義。 這意味着您不能使用其origin成員來更改視圖的位置。 您必須改為使用視圖的center屬性。

另外，對於拖動，我強烈建議您使用UIPanGestureRecognizer而不是UIPanGestureRecognizer touches...方法。 這是因為手勢識別器可以為您保持狀態，並且拖動事物非常容易。

這是一些示例代碼：

// Create your view and apply all the transforms you want
// --code here--

// Create and assign the UIPanGestureRecognizer
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panDetected:)];
[self.currentView addGestureRecognizer:panGesture];

// Here is where the dragging happens
-(void)panDetected:(UIPanGestureRecognizer*)panGesture {

    // Get the view that detected the gesture
    UIView *view = panGesture.view;

    // If dragging started or changed...
    if (panGesture.state == UIGestureRecognizerStateBegan || panGesture.state == UIGestureRecognizerStateChanged) {

        // Get the translation in superview coordinates
        CGPoint translation = [panGesture translationInView:view.superview];

        // Get your view's center
        CGPoint viewCenter = view.center;

        // Add the delta 
        viewCenter.x += translation.x;
        viewCenter.y += translation.y;
        view.center = viewCenter;

        // Reset delta from the gesture recognizer
        [panGesture setTranslation:CGPointZero inView:view.superview];
    }
}

我在一個我的項目中測試了此代碼，該項目的視圖具有旋轉變換並且可以完美運行。

希望這可以幫助！