IOS 7 Safari就像历史使用uiwebview拖动手势一样

Question

如果您在ios 7中看到safari应用程序左右拖动以查看网页的历史记录.它还会在拖动时显示上一页的内容.我想要使​​用UIWebiview的类似功能.

我可以前进和后退页面但是如何实现显示以前内容的拖动功能？

Answer 1

注意:这只是iOS 7.对于iOS 6,您应该使用PanGestureRecognizer并检测它是左还是右.

你需要两个属性:

@property (nonatomic, strong) UIImageView * imgvcChild1;
@property (retain, strong) IBOutlet UIWebView *webView;

首先,将手势识别器添加到webView:

[[UIScreenEdgePanGestureRecognizer alloc] initWithTarget:self action:@selector(EdgeLeftPanDetected:)];
panLeft.edges = UIRectEdgeLeft;
[self.webView addGestureRecognizer:panLeft];

控制手势:

- (void) EdgeLeftPanDetected:(UIScreenEdgePanGestureRecognizer*)gesture {

    if (gesture.state == UIGestureRecognizerStateBegan) {

        UIGraphicsBeginImageContext ( self.webView.frame.size );
        [self.webView.layer renderInContext:UIGraphicsGetCurrentContext() ];

        UIImage *grab = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

        if ( _imgvcChild1 ) [ _imgvcChild1 removeFromSuperview ];
        _imgvcChild1 = [[ UIImageView alloc ] initWithImage:grab ];
        _imgvcChild1.frame = self.webView.frame;
        _imgvcChild1.userInteractionEnabled = YES;
        _imgvcChild2 = [self.arrayImagenes lastObject];
        if ([self.webView canGoBack]) {

            [self.webView goBack];

        } 

        [ self.view addSubview:_imgvcChild1 ];

    }

    if (gesture.state == UIGestureRecognizerStateChanged) {
        _imgvcChild1.frame = CGRectMake([ gesture locationInView:_imgvcChild1.superview ].x, _imgvcChild1.frame.origin.y, _imgvcChild1.frame.size.width, _imgvcChild1.frame.size.height);

         }

    }

    if (gesture.state == UIGestureRecognizerStateEnded) {

        [_imgvcChild1 removeFromSuperview];

    }
}

这是一个原型,它需要大量的工作,它只是为了回头而你回去的页面没有动画.如果你想在上一页中有动画,你需要在加载新页面之前创建一个图像并将其存储在一个图像上NSMutableArray,然后用不同的动画显示它(这个图像像屏幕的-1/4一样开始,就像速度的1/4 imgvcChild1)

UIImageViews如果你想要前进,你还需要另一个右手势识别器和另一个阵列.