如何限制平移手势区域？ [英] How to limit pan gesture area?

问题描述

我正在使用 UIImageView ，我正在使用另一个 UIView 矩形。通过将平移手势应用于 UIView 矩形，它也会超出 UIImageView 。我不想被拖出 UIImageView

I am having my UIImageView onto which I am having another UIView rectangle. By applying pan gesture to UIView rectangle it gets outside of UIImageView also. I don't want to be drag outside of UIImageView

我试过下面的代码，但它不起作用方式

I have tried below code but it is not working that way

-(void)handleMovementView:(UIPanGestureRecognizer *)recognizer
{
    CGPoint movement;

    if(recognizer.state == UIGestureRecognizerStateBegan || recognizer.state == UIGestureRecognizerStateChanged || recognizer.state == UIGestureRecognizerStateEnded)
    {
        CGRect rec = recognizer.view.frame;
        CGRect imgvw = self.imgViewCrop.frame;
        if((rec.origin.x >= imgvw.origin.x && (rec.origin.x + rec.size.width <= imgvw.origin.x + imgvw.size.width)))
        {
            CGPoint translation = [recognizer translationInView:recognizer.view.superview];
            movement = translation;
            recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x, recognizer.view.center.y + translation.y);
            [recognizer setTranslation:CGPointZero inView:recognizer.view.superview];
            [self handleMovementForHandlers:movement];
        }
    }

}

如果我应用Pan慢慢应用这个条件，但是当我快速移动时它超出了ImageView

If i apply Pan slowly it applies this condition but when i go fast it went outside of ImageView

推荐答案

试试这个

-(void)handleMovementView:(UIPanGestureRecognizer *)recognizer
{
CGPoint movement;

if(recognizer.state == UIGestureRecognizerStateBegan || recognizer.state == UIGestureRecognizerStateChanged || recognizer.state == UIGestureRecognizerStateEnded)
{
    CGRect rec = recognizer.view.frame;
    CGRect imgvw = self.imgViewCrop.frame;
    if((rec.origin.x >= imgvw.origin.x && (rec.origin.x + rec.size.width <= imgvw.origin.x + imgvw.size.width)))
    {
        CGPoint translation = [recognizer translationInView:recognizer.view.superview];
        movement = translation;
        recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x, recognizer.view.center.y + translation.y);
        rec = recognizer.view.frame;

        if( rec.origin.x < imgvw.origin.x )
            rec.origin.x = imgvw.origin.x;

        if( rec.origin.x + rec.size.width > imgvw.origin.x + imgvw.size.width )
            rec.origin.x = imgvw.origin.x + imgvw.size.width - rec.size.width;

        recognizer.view.frame = rec;

        [recognizer setTranslation:CGPointZero inView:recognizer.view.superview];
        [self handleMovementForHandlers:movement];
    }
}
}

这篇关于如何限制平移手势区域？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！