android - 在可绘制图像上添加一个String？

Question

我试图在Drawable图片上添加String。我目前没有使用Panel进行绘制，我想保持这种状态。任何想法或我是否需要调用onDraw()方法？

我的图像显示了这个代码：

Drawable image = getResources().getDrawable(tile_types[tileType]);  
setImageDrawable(image); 

我想在这个图像添加String。

谢谢。

Answer 1

http://developer.android.com/reference/android/graphics/Canvas.html

Answer 2

Drawable image = getResources().getDrawable(tile_types[tileType]); 
// Store our image size as a constant 
final int IMAGE_WIDTH = image.getIntrinsicWidth(); 
final int IMAGE_HEIGHT = image.getIntrinsicHeight(); 

// You can also use Config.ARGB_4444 to conserve memory or ARGB_565 if 
// you don't have any transparency. 
Bitmap canvasBitmap = Bitmap.createBitmap(IMAGE_WIDTH, 
              IMAGE_HEIGHT, 
              Bitmap.Config.ARGB_8888); 
// Create a canvas, that will draw on to canvasBitmap. canvasBitmap is 
// currently blank. 
Canvas imageCanvas = new Canvas(canvasBitmap); 
// Set up the paint for use with our Canvas 
Paint imagePaint = new Paint(); 
imagePaint.setTextAlign(Align.CENTER); 
imagePaint.setTextSize(16f); 

// Draw the image to our canvas 
image.draw(imageCanvas); 
// Draw the text on top of our image 
imageCanvas.drawText("Sample Text", 
         IMAGE_WIDTH/2, 
         IMAGE_HEIGHT/2, 
         imagePaint); 
// This is the final image that you can use 
BitmapDrawable finalImage = new BitmapDrawable(canvasBitmap); 

Answer 3

萨姆的回答是我的出发点，但图像没有露面，只有文字（我用它在谷歌地图）。最后，我得到了它与LayerDrawable工作。这里是我的解决方案：

private Drawable createMarkerIcon(Drawable backgroundImage, String text, 
            int width, int height) { 

    Bitmap canvasBitmap = Bitmap.createBitmap(width, height, 
              Bitmap.Config.ARGB_8888); 
    // Create a canvas, that will draw on to canvasBitmap. 
    Canvas imageCanvas = new Canvas(canvasBitmap); 

    // Set up the paint for use with our Canvas 
    Paint imagePaint = new Paint(); 
    imagePaint.setTextAlign(Align.CENTER); 
    imagePaint.setTextSize(16f); 

    // Draw the image to our canvas 
    backgroundImage.draw(imageCanvas); 

    // Draw the text on top of our image 
    imageCanvas.drawText(text, width/2, height/2, imagePaint); 

    // Combine background and text to a LayerDrawable 
    LayerDrawable layerDrawable = new LayerDrawable(
      new Drawable[]{backgroundImage, new BitmapDrawable(canvasBitmap)}); 
    return layerDrawable; 
} 

Answer 4

如果导致文字看起来“角”由于调整大小，最好使用TextPaint而不是纯Paint与这些参数：

TextPaint textPaint = new TextPaint(TextPaint.ANTI_ALIAS_FLAG | TextPaint.LINEAR_TEXT_FLAG);