OC_图片放大缩小_移动手势综合

最新推荐文章于 2020-11-13 17:34:13 发布

ifanyong

最新推荐文章于 2020-11-13 17:34:13 发布

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分类专栏： iOS_基础文章标签： uiimageview 手势 oc 图片放大缩小图片

本文链接：https://blog.youkuaiyun.com/iOS_And_Swift/article/details/46971485

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本文介绍了如何在Objective-C（OC）中实现UIImageView的交互功能，包括图片的放大、缩小和移动操作。通过scaleImage函数实现图片的缩放，同时详细讲述了拖动图片的实现过程。提供了一个Demo地址，供读者参考，该Demo具有类似微信图片查看的效果。

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1.创建UIImageView打开交互

 UIImageView * imageV= [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, kScreen
idth,
kScreenHeight)];
imageV.contentMode =  UIViewContentModeScaleAspectFit ;//UIView的填充模式
        imageV.userInteractionEnabled = YES ;//打开交互
       //手势
        UIPinchGestureRecognizer * pin =[[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(scaleImage:)];
        [imageV addGestureRecognizer:pin];

2.实现放大缩小scaleImage函数

-(void)scaleImage:(UIPinchGestureRecognizer *)sender{


        CGFloat value;
    if (sender.state ==  UIGestureRecognizerStateEnded) {
        _lastScale = 1.0 ;//在手势结束时候 要重置为1.0的，否则下次变化会大小突变
        [UIView animateWithDuration:0.25 animations:^{
            // sender.view.frame = CGRectMake(kScreenWidth * sender.view.tag, 0, kScreenWidth, kScreenHeight);
        }];

        return ;
    }
    else if(sender.state == UIGestureRecognizerStateChanged) {
        double scaleValue = 1.0 + sender.scale - _lastScale;
       ;
        value = scaleValue ;
        CGAffineTransform   treans =  (sender.view.transform);
        CGAffineTransform   transNew =CGAffineTransformScale( treans, value, value);
        sender.view.transform = transNew ;
        _lastScale = sender.scale ;
    // NSLog(@"value:%f  now:%f  last:%f",sender.scale,scaleValue,_lastScale);
    }

//    UIScrollView * superView =(UIScrollView*) sender.view.superview;
//    superView.contentSize= CGSizeMake(getWidth(sender.view.frame), getHeight(sender.view.frame));

}

3.拖动

 UIPanGestureRecognizer * pan =[[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(pan:)];
        [imageV addGestureRecognizer:pan];

4.拖动实现

-(void)pan:(UIPanGestureRecognizer *)sender{
    CGPoint location = [sender translationInView:sender.view];
    sender.view.transform = CGAffineTransformTranslate(sender.view.transform ,location.x , location.y);
    [sender setTranslation:CGPointZero inView:sender.view];
}

Demo地址
里边有可以直接用的类似微信的图片点击效果，可以看看。