import android.os.Bundle;  
    import android.widget.ImageView;  
    import android.app.Activity;  
    import android.graphics.Bitmap;  
    import android.graphics.Canvas;  
    import android.graphics.Color;  
    import android.graphics.Paint;  
    import android.graphics.drawable.BitmapDrawable;  
    import android.graphics.drawable.Drawable;  
      
    public class MainActivity extends Activity {  
      
        @Override  
        protected void onCreate(Bundle savedInstanceState) {  
            super.onCreate(savedInstanceState);  
            setContentView(R.layout.activity_main);  
      
            ImageView iv = (ImageView) findViewById(R.id.imageView);  
      
            //为简单期间，就使用Android原生的小机器人为目标图片  
            Drawable drawable = getResources().getDrawable(R.drawable.ic_launcher);  
      
            // Drawable -> Bitmap：Drawable 转换成 Bitmap。  
            BitmapDrawable bd = (BitmapDrawable) drawable;  
            Bitmap bmp = bd.getBitmap();  
      
            // 为Bitmap添加水印  
            Bitmap bitmap = createWatermark(bmp, "@ Zhang Phil");  
      
            iv.setImageBitmap(bitmap);  
        }  
      
        // 为图片target添加水印文字  
        // Bitmap target：被添加水印的图片  
        // String mark：水印文章  
        private Bitmap createWatermark(Bitmap target, String mark) {  
            int w = target.getWidth();  
            int h = target.getHeight();  
      
            Bitmap bmp = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);  
            Canvas canvas = new Canvas(bmp);  
      
            Paint p = new Paint();  
      
            // 水印的颜色  
            p.setColor(Color.RED);  
      
            // 水印的字体大小  
            p.setTextSize(10);  
      
            p.setAntiAlias(true);// 去锯齿  
      
            canvas.drawBitmap(target, 0, 0, p);  
      
            // 在左边的中间位置开始添加水印  
            canvas.drawText(mark, 0, h / 2, p);  
      
            canvas.save(Canvas.ALL_SAVE_FLAG);  
            canvas.restore();  
      
            return bmp;  
        }  
    }