从MapKit获取中心坐标并显示在UILabel中 [英] Get center coordinates from MapKit and display in UILabel

问题描述

我正在使用XCode 7.2和Swift 2.1开发iOS应用，并且已经在我的应用中成功实现了MapKit地图.地图会完美加载，并以用户当前位置为中心.

I'm developing an iOS app using XCode 7.2 and Swift 2.1, and I've successfully implemented a MapKit map in my app. The map loads perfectly and centers on the user's current location.

现在，如果用户将地图中心移动到新位置，我想检索中心坐标.按下按钮(请参阅随附的gif中的设置网格参考"按钮)，将捕获"该新位置的坐标，并显示在标签中.

Now I want to retrieve the center coordinates should the user move the center of the map to a new location. This new location's coordinates will be "captured" on the press of a button (see the "Set Grid Reference" button in the attached gif) and be displayed in a label.

从A移到B并设置新的中心坐标

最接近我的答案是此处，并且我已经实现了该代码，但是我仍然不知道如何通过单击创建的IBOutlet按钮来使用坐标更新标签.

The closest I've come to an answer is here, and I've implemented that code, but I still can't figure out how to update the label with the coordinates by clicking the IBOutlet button I've created.

我在这里想念什么?！

任何帮助将不胜感激-预先感谢！

Any help would be highly appreciated - thanks in advance!

----------------关注的问题------------------

----------------FOLLOW-ON QUESTION------------------

现在我们已经解决了问题，并在标签上填充了新的中心坐标，我还有一个问题-最有可能是菜鸟监督，但是我的学习曲线很陡峭，所以请耐心等待我...

Now that we've solved the problem and we got the label populated with the new center coordinates, I have one more question - most probably a noob oversight, but I'm on a steep learning curve here, so please bear with me...

我们已经成功确定了中心坐标，现在已在我们创建的函数中将其设置为 mapLongitude 和 mapLatitude .

We have successfully determined the center coordinates and they are now set as mapLongitude and mapLatitude inside the function we've created.

我还有另外两个变量( newTargetLong 和 newTargetLat )，这些变量构成了将传递给下一个视图控制器的值数组的一部分，我想:

I have two other variables (newTargetLong and newTargetLat) that forms part of an array of values that will be passed on to the next view controller, and I want to:

let newTargetLong = mapLongitude
let newTargetLat = mapLatitude

，以便可以使用.append指令将新的纬度和经度添加到数组中.

so that the new latitude and longitude can be added to the array with an .append instruction.

但是由于某种原因，我无法从该函数中取出"这两个值.我需要怎么做才能做到这一点?

But for some reason, I just can't get those two values "out" of that function. What do I need to do to accomplish that?

推荐答案

在类顶部使用其他声明声明var center = "".在下面的方法中，它应该自动更改center的值:

Declare var center = "" at the top of your class with other declarations. In the method below, it should automatically change the value of center:

func mapView(mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
    center = mapView.centerCoordinate
}

按下按钮时，将标签的值设置为center的值.

When you press your button set the value of your label to the value of center.

self.yourLabelName.text = center

要显示为纬度:...经度:..."，请执行以下操作:

To display as "Latitude: ... Longitude: ..." do as follows:

func mapView(mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
    let mapLatitude = mapView.centerCoordinate.latitude
    let mapLongitude = mapView.centerCoordinate.longitude
    center = "Latitude: \(mapLatitude) Longitude: \(mapLongitude)"
    print(center)
    self.yourLabelName.text = center
}

如果要设置坐标格式以显示更友好的内容:

If you want to format the coordinates to display a little more friendly:

center = "\(String(format: "%.5f", mapLatitude)), \(String(format: "%.5f", mapLongitude))"

根据您偏好的小数位数调整％.5f.

Adjust the %.5f according to your preference of number of decimal places.

这篇关于从MapKit获取中心坐标并显示在UILabel中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！