一个UIViewController
UITableViewCell
当用户触摸 a上的图像时调用它被称为使用modalViewController
。这modalViewController
是一个UIScrollView
,中间是另一个,它使用(从 传递)UIImageView
获取图像。NSDictionary
UITableViewCell
现在,我想要实现的是用户只能垂直拖动图像的能力,这样稍微拖动和释放就会使图像以动画方式返回到中心。如果用户将其拖到极端,则整个UIScrollView
被解除并且用户返回到UITableView
. 我使用了以下代码。这里的问题是,正如我的名字所暗示的那样,这段代码很粗糙。有没有一种优雅的方式来做到这一点,而不需要这么多的计算?
BOOL imageMoved=NO;
- (void) touchesMoved:(NSSet *)touches
withEvent:(UIEvent *)event {
UITouch * touch = [touches anyObject];
CGPoint pos = [touch locationInView: [UIApplication sharedApplication].keyWindow];
CGRect imageRect = _photoImageView.frame;//_photoImageView object of UIImageView
CGFloat imageHeight = imageRect.size.height;//getting height of the image
CGFloat imageTop=240-imageHeight/2;
CGFloat imageBottom=imageTop+imageHeight;//setting boundaries for getting coordinates of touch.
// Touches that originate above imageTop and below imageBottom are ignored(until touch reaches UIImageView)
if (pos.y>50&&pos.y<430&&pos.y>=imageTop&&pos.y<=imageBottom){//extremes are defined as top and bottom 50 pixels.
imagedMoved=YES;//BOOL variable to hold if the image was dragged or not
NSLog(@"%f", pos.y);
[UIView setAnimationDelay:0];
[UIView animateWithDuration:0.4
animations:^{_photoImageView.frame=CGRectMake(0,pos.y-imageHeight/2,320,200);}
completion:^(BOOL finished){ }];
}
}
- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch * touch = [touches anyObject];
CGPoint pos = [touch locationInView: [UIApplication sharedApplication].keyWindow];
if (pos.y>50&&pos.y<430){//if touch has NOT ended in the extreme 50 pixels vertically
[UIView setAnimationDelay:0];//restoring UIImageView to original center with animation
[UIView animateWithDuration:0.4
animations:^{_photoImageView.frame=CGRectMake(0,140,320,200);}
completion:^(BOOL finished){ }];
imagedMoved=NO;//prepare BOOL value for next touch event
}
else if(pos.y<50||pos.y>430)
if(imagedMoved)
[self.photoBrowser exit] ;//exit function(imported from UIScrollViewController) dismisses
//modalView using [self dismissViewControllerAnimated:YES completion:nil];
}
这里的所有代码都是对自定义副本的修改UITapView
这里的所有代码都是对inMWPhotoBrowser
。