GoogleMap快照方法返回白色图像

Question

我正在尝试使用此处提到的API获取Google Maps V2地图的屏幕截图,但这似乎总是返回底部带有Google徽标的白色图片.如果它不是徽标,我会确定这根本不起作用,但徽标意味着发生了一些事情并且地图没有显示.这大致就是我正在做的事情:

mv.setVisibility(View.VISIBLE);
mv.getMap().snapshot(new GoogleMap.SnapshotReadyCallback() {
    public void onSnapshotReady(Bitmap snapshot) {
        synchronized(finished) {
            finished[0] = snapshot;
            finished.notify();
        }
    }
});

我尝试了多种不同的方法,包括将图像绘制到不同的图像和各种其他尝试.

唯一的主要区别是我使用MapView而不是MapFragment,因为我在这里无法切换到使用片段的一些技术问题.

Answer 1

要拍摄快照,您需要等待地图加载然后拍摄快照.

详细信息:实现SnapshotReadyCallback和OnMapLoadedCallback.

import com.google.android.gms.maps.GoogleMap.SnapshotReadyCallback;
import com.google.android.gms.maps.GoogleMap.OnMapLoadedCallback;

public class KmlReader extends ActionBarActivity implements
     SnapshotReadyCallback,
    OnMapLoadedCallback {

...

 if (mMap == null) {
// Try to obtain the map from the SupportMapFragment.
// mMap = mMapFragment.getMap();
// // Check if we were successful in obtaining the map.

// Try to obtain the map from the SupportMapFragment.
mMap = ((SupportMapFragment) getSupportFragmentManager()
        .findFragmentById(R.id.map)).getMap();
// use the settings maptype

// Check if we were successful in obtaining the map.
if (mMap != null) {

mMap.setOnMapLoadedCallback(this);

...

@Override
public void onMapLoaded() {
   if (mMap != null) {
        mMap.snapshot(this);
   }
}

当它触发时你有一个真正的位图.

@Override
public void onSnapshotReady(Bitmap bm) {
    if (CheckStorage.isExternalStorageWritable()) {
        int newHeight = 96;
        int newWidth = 96;

        int width = bm.getWidth();

        int height = bm.getHeight();

        float scaleWidth = ((float) newWidth) / width;

        float scaleHeight = ((float) newHeight) / height;

        // create a matrix for the manipulation

        Matrix matrix = new Matrix();

        // resize the bit map

        matrix.postScale(scaleWidth, scaleHeight);

        // recreate the new Bitmap

        Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height,
                matrix, false);