在多边形Android Google地图v2上显示文本

问题描述

我在地图上使用多边形，我想在其上输入文字.有什么可行的方法吗?我试图在地图点上放置简单的文本，但没有成功.

I am using polygons on map and I want to have a text on them. Is there any possible way to do this? I tried to put simple text on map point but didn't make it.

 private void addPolygon(Region reg) {
             PolylineOptions polylineOptions = new PolylineOptions();
             ArrayList<LatLng> coordList=reg.getAllPoints();
             coordList.add(coordList.get(0));
             int regColor = reg.getColor();
             String regName = reg.getName();
             //want to put a name on region
             polylineOptions.addAll(coordList);
             polylineOptions
              .width(5)
              .color(Color.BLACK);
             if (regColor != 0)
                 polylineOptions
                  .color(regColor);
             map.addPolyline(polylineOptions);
            //text on shape?
        }

推荐答案

您可以创建带有自定义图标的 Marker ，然后在该图标上绘制文本.您可以使用如下方法:

You can create a Marker with a custom icon, and draw the text on that icon. You can use a method like this:

public Marker addText(final Context context, final GoogleMap map,
        final LatLng location, final String text, final int padding,
        final int fontSize) {
    Marker marker = null;

    if (context == null || map == null || location == null || text == null
            || fontSize <= 0) {
        return marker;
    }

    final TextView textView = new TextView(context);
    textView.setText(text);
    textView.setTextSize(fontSize);

    final Paint paintText = textView.getPaint();

    final Rect boundsText = new Rect();
    paintText.getTextBounds(text, 0, textView.length(), boundsText);
    paintText.setTextAlign(Align.CENTER);

    final Bitmap.Config conf = Bitmap.Config.ARGB_8888;
    final Bitmap bmpText = Bitmap.createBitmap(boundsText.width() + 2
            * padding, boundsText.height() + 2 * padding, conf);

    final Canvas canvasText = new Canvas(bmpText);
    paintText.setColor(Color.BLACK);

    canvasText.drawText(text, canvasText.getWidth() / 2,
            canvasText.getHeight() - padding - boundsText.bottom, paintText);

    final MarkerOptions markerOptions = new MarkerOptions()
            .position(location)
            .icon(BitmapDescriptorFactory.fromBitmap(bmpText))
            .anchor(0.5f, 1);

    marker = map.addMarker(markerOptions);

    return marker;
}

您将需要设置标记的位置 LatLng ，并且必须从您的 Region (例如，几何的第一个点，最后一个点)进行计算点，随机点，质心...).

You will need to set the location LatLng of the marker and you will have to calculate it from your Region (for example the first point of the geometry, the last point, a random point, the centroid, ...).

还要考虑到绘制很多标记会对性能产生负面影响.

Also, take into account that drawing a lot of markers will have a negative effect in the performance.

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