android - 如何在图像上绘制文本？

Question

我想在图像上绘制文本(用于将该图像与文本一起保存)。我有 ImageView 我将位图设置为我想在图像上绘制文本(用户输入的文本)的图像。我在保存之前试过这个.....

void saveImage() {
    File myDir=new File("/sdcard/saved_images");
    myDir.mkdirs();
    Random generator = new Random();
    int n = 10000;
    n = generator.nextInt(n);
    String fname = "Image-"+ n +".jpg";
    File file = new File (myDir, fname);
    if (file.exists ()) file.delete (); 
    try {
           FileOutputStream out = new FileOutputStream(file);
           originalBitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
           out.flush();
           out.close();

    } catch (Exception e) {
           e.printStackTrace();
    }
}

Xml 代码是..

<FrameLayout 
     android:id="@+id/framelayout"
     android:layout_marginTop="30dip"
     android:layout_height="fill_parent" 
     android:layout_width="fill_parent">

     <ImageView 
          android:id="@+id/ImageView01"
          android:layout_alignParentTop="true"
          android:layout_height="wrap_content" 
          android:layout_width="wrap_content"/>

     <TextView android:id="@+id/text_view2"
          android:layout_marginTop="20dip"
          android:layout_width="wrap_content" 
          android:text="SampleText"
          android:textSize="12pt"
          android:layout_alignTop="@+id/ImageView01" 
          android:layout_height="wrap_content"/>  

</FrameLayout>

Answer 1

作为 suggested by Vladislav Skoumal ，试试这个方法:

public Bitmap drawTextToBitmap(Context mContext,  int resourceId,  String mText) {
    try {
         Resources resources = mContext.getResources();
         float scale = resources.getDisplayMetrics().density;
         Bitmap bitmap = BitmapFactory.decodeResource(resources, resourceId);
         android.graphics.Bitmap.Config bitmapConfig =   bitmap.getConfig();
         // set default bitmap config if none
         if(bitmapConfig == null) {
           bitmapConfig = android.graphics.Bitmap.Config.ARGB_8888;
         }
         // resource bitmaps are imutable,
         // so we need to convert it to mutable one
         bitmap = bitmap.copy(bitmapConfig, true);

         Canvas canvas = new Canvas(bitmap);
         // new antialised Paint
         Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
         // text color - #3D3D3D
         paint.setColor(Color.rgb(110,110, 110));
         // text size in pixels
         paint.setTextSize((int) (12 * scale));
         // text shadow
         paint.setShadowLayer(1f, 0f, 1f, Color.DKGRAY);

         // draw text to the Canvas center
         Rect bounds = new Rect();
         paint.getTextBounds(mText, 0, mText.length(), bounds);
         int x = (bitmap.getWidth() - bounds.width())/6;
         int y = (bitmap.getHeight() + bounds.height())/5;

         canvas.drawText(mText, x * scale, y * scale, paint);

         return bitmap;
    } catch (Exception e) {
        // TODO: handle exception

        return null;
    }

}

调用这个方法

Bitmap bmp =drawTextToBitmap(this,R.drawable.aa,"Hello Android");
img.setImageBitmap(bmp);

输出