如何使用 Android map API v2 创建自定义形状的位图标记

在Google Maps API v2 Demo中有一个MarkerDemoActivity类，你可以看到自定义图像是如何设置为谷歌 map 的.

// Uses a custom icon.
mSydney = mMap.addMarker(new MarkerOptions()
    .position(SYDNEY)
    .title("Sydney")
    .snippet("Population: 4,627,300")
    .icon(BitmapDescriptorFactory.fromResource(R.drawable.arrow)));

因为这只是用一幅图像替换了标记，所以你可能想用Canvas来画更复杂、更华丽的东西:

Bitmap.Config conf = Bitmap.Config.ARGB_8888;
Bitmap bmp = Bitmap.createBitmap(80, 80, conf);
Canvas canvas1 = new Canvas(bmp);

// paint defines the text color, stroke width and size
Paint color = new Paint();
color.setTextSize(35);
color.setColor(Color.BLACK);

// modify canvas
canvas1.drawBitmap(BitmapFactory.decodeResource(getResources(),
    R.drawable.user_picture_image), 0,0, color);
canvas1.drawText("User Name!", 30, 40, color);

// add marker to Map
mMap.addMarker(new MarkerOptions()
    .position(USER_POSITION)
    .icon(BitmapDescriptorFactory.fromBitmap(bmp))
    // Specifies the anchor to be at a particular point in the marker image.
    .anchor(0.5f, 1));

这会将画布canvas1绘制到画布GoogleMap mMap上.代码应该(主要)说明问题，有很多教程教你如何画Canvas.你可以从Android开发者页面上的Canvas and Drawables开始.

现在，您还需要从URL下载图片.

URL url = new URL(user_image_url);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();   
conn.setDoInput(true);   
conn.connect();     
InputStream is = conn.getInputStream();
bmImg = BitmapFactory.decodeStream(is); 

你可以从后台线程下载图像(你可以使用AsyncTask、Volley或RxJava).

之后，您可以用下载的图像bmImg替换BitmapFactory.decodeResource(getResources(), R.drawable.user_picture_image).