如何将GeoPoint转换为硬件屏幕点 [英] How to convert a GeoPoint to a Hardware screen point

问题描述

我想将GeoPoint转换为屏幕点，以便识别触摸事件上方的所有对象. 所以，我已经尝试过了:

I would like to convert a GeoPoint to a screen point in order to identify all objects which are above a touch event. So, I've tried this :

Projection projection = this.mapView.getProjection(); 
GeoPoint gie = new GeoPoint(lat, lon);
Point po = new Point();
projection.toPixels(gie, po);

但是，po.x和po.y不是屏幕坐标，而是mapview坐标(以像素为单位，而不是lat，lon).

But, po.x and po.y are not the screen coords, but the mapview coords in pixel instead of lat,lon.

从android开发者网站:

From the android developer website :

toPixels(GeoPoint输入，android.graphics.Point输出) 相对于提供此Projection的MapView的左上角，将给定的GeoPoint转换为屏幕上的像素坐标.

toPixels(GeoPoint in, android.graphics.Point out) Converts the given GeoPoint to onscreen pixel coordinates, relative to the top-left of the MapView that provided this Projection.

那么，有可能将其转换为正确的屏幕坐标吗?

So, is it possible to convert it in the correct screen coords ?

我想知道 + 触摸事件旁边的所有 x GeoPoint，就像上面的示例一样:

I want to know all the x GeoPoint which are next to the + touch event like on the example above :

----------------------------------------------------------------
(0,0) -----------> x                                           |
  |                                                            |
  |                                                            | 
  |                                                            |  <-- My screen
  |                              + (touch event)               |
 \/                            x (my GeoPoint)                 |
  y                                                            |
                                                               | 
---------------------------------------------------------------- 

我得到了这样的触摸事件:

I get the touch event like that :

@Override
public boolean onTouchEvent(MotionEvent event) {
    float x = event.getX();
    float y = event.getY();

在此代码中，x和y是实际的屏幕坐标(硬件坐标，而不是mapview坐标)

Here, in this code, x and y are the real screen coords (the hardware ones, not the mapview ones)

我知道我也可以在GeoPoint中转换x，y屏幕坐标，以将它们与我的GeoPoint进行比较，但是，由于缩放级别的原因，我无法获得想要的.

I know that I can also convert x,y screen coordinates in GeoPoint to compare them to my GeoPoint, but, because of the zoom level, I can't get what I want.

推荐答案

我已经找到了解决方案，我不知道这是否是获得它的最佳方法，但是它有效！

I've found a solution, I don't know if it's the best way to get it, but it works!

我发现感谢@nickt的帮助，方法 getScreenRect() 返回屏幕坐标的当前边界.

I've found thank to your help @nickt, the method getScreenRect() which return the current bounds of the screen in screen coordinates.

代码在这里:

float pisteX;
float pisteY;
Projection projection = this.mapView.getProjection(); 
Point pt = new Point();
GeoPoint gie = new GeoPoint(latitude,longitude);
Rect rec = mapView.getScreenRect(new Rect());
projection.toPixels(gie, pt);
pisteX = pt.x-rec.left; // car X screen coord
pisteY = pt.y-rec.top; // car Y screen coord

这篇关于如何将GeoPoint转换为硬件屏幕点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！