UIScrollView ImageView顶部有针脚 [英] UIScrollView ImageView with pins on top

问题描述

我有一个 UIScrollView ，它有一个 UIImageView 。我想在这个 imageView 上显示引脚。当我添加引脚作为 ImageView 的子视图时，一切都很棒，除了当缩放比例变换发生在引脚上时。我不希望这种行为，并希望我的引脚保持不变。

I have a UIScrollView which has a UIImageView. I want to show pins on this imageView. When I add pins as subviews of the ImageView, everything is great except for when you zoom the scale transform happens on the pins also. I don't want this behavior and want my pins to stay the same.

所以我选择将Pins添加到位于ImageView顶部的另一个视图，并且也是 UIScrollView 的子视图。如果你想象的话，这里的想法是有一个悬浮在地图上的图层，并且不会缩放，而是在我绘制它们的地方显示引脚。

So I choose to add the Pins to another view which sits on top of the ImageView and is also a subview of the UIScrollView. The idea here if you will imagine is to have a layer which hovers over the map and won't scale yet show pins over where I plot them.

添加时的引脚如果 ImageView 缩放，则不会对图层视图进行编译。但是，由于 ImageView 已经进行了比例变换，因此问题变成了引脚的位置与原始x / y不匹配。

The pin when added to the layer view don't cale if the ImageView scales. However, the issue then becomes the position of the pins doesn't match the original origin x/y as the ImageView has had a scale transform.

基本上这是一个带有Pins的地方的自定义地图。我试图让Pins漂浮而不是放大和缩小我的ImageView但还记得我在缩放发生时放置它们的位置。

Basically this is a custom map of a place with Pins. I am trying to have the Pins float over and not zoom in and out over my ImageView yet remember where I placed them when the zoom happens.

一些代码：

scrollView = [[UIScrollView alloc] initWithFrame:viewRect];

scrollView.delegate = self;
scrollView.pagingEnabled = NO;
scrollView.scrollsToTop = NO;
[scrollView setBackgroundColor:[UIColor clearColor]];
scrollView.clipsToBounds = YES; // default is NO, we want to restrict drawing within our scrollview
scrollView.bounces = YES;
scrollView.autoresizingMask = UIViewAutoresizingFlexibleHeight;
scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;

imageViewMap = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"image.png"]];

imageViewMap.userInteractionEnabled = YES;

viewRect = CGRectMake(0,0,imageViewMap.image.size.width,imageViewMap.image.size.height);

//viewRect = CGRectMake(0,0,2976,3928);

[scrollView addSubview:imageViewMap];

[scrollView setContentSize:CGSizeMake(viewRect.size.width, viewRect.size.height)];

iconsView = [[UIView alloc] initWithFrame:imageViewMap.frame];

[scrollView addSubview:iconsView];

稍后在某些活动上添加Pin的代码。

Code to add Pin later on some event.

[iconsView addSubview:pinIcon];

我一直试图弄清楚如何让我的别针悬停在地图上而不移动当比例发生时。

I am stuck in trying tp figure out how to to get my pins to hover on the map without moving when the scale happens.

推荐答案

我喜欢你将所有引脚保留在专用于引脚（iconView）的视图中的想法，但是我决定只将它们添加为你所谓的imageViewMap的子视图。

I like your idea of keeping all the pins in a view dedicated to pins (iconsView), but I decided to just add them as subviews of what you called imageViewMap.

将QuartzCore.framework文件导入你的项目。

Import the QuartzCore.framework file to your project.

调用视图控制器MyViewController。

Call your view controller MyViewController.

#import <QuartzCore/QuartzCore.h>
@interface MyViewController : UIViewController <UIScrollViewDelegate>
@property (retain) UIScrollView *scrollView;
@property (retain) UIImageView *imageView;

//等等

@implementation MyViewController

@synthesize scrollView;
@synthesize imageView;

我假设你有一个pin视图或一个名为DropPinViewController的视图控制器。如果您只是使用图像，它可以是UIImageView，但我的图钉有标签，所以我使用了一个xib。引脚应该指向xib的底部中心，因为我们要在那里放置一个锚点。

I'll assume you have a pin view or a view controller called DropPinViewController. If you're just using an image, it can be a UIImageView, but my pins have labels, so I used a xib. The pin should point to the bottom center of the xib because we're going to put an anchor point there.

在你的MyViewController的viewDidLoad中，添加引脚视图为imageView的子视图。将imageView作为子视图添加到scrollView。设置scrollView的内容大小。

In your viewDidLoad of your MyViewController, add your pin views as subviews of imageView. Add the imageView as a subview to the scrollView. Set the content size of scrollView.

scrollView.delegate = self;

使用这些委托方法：

- (void)scrollViewDidZoom:(UIScrollView *)aScrollView
{   
    for (UIView *dropPinView in imageView.subviews) {       
    CGRect oldFrame = dropPinView.frame;
    // 0.5 means the anchor is centered on the x axis. 1 means the anchor is at the bottom of the view. If you comment out this line, the pin's center will stay where it is regardless of how much you zoom. I have it so that the bottom of the pin stays fixed. This should help user RomeoF.
   [dropPinView.layer setAnchorPoint:CGPointMake(0.5, 1)];
    dropPinView.frame = oldFrame;
    // When you zoom in on scrollView, it gets a larger zoom scale value.
    // You transform the pin by scaling it by the inverse of this value.
    dropPinView.transform = CGAffineTransformMakeScale(1.0/scrollView.zoomScale, 1.0/scrollView.zoomScale);
}

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return imageView;
}

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