在jpg图像android上绘制文本

Question

我在里面有一个jpg图像作为字节数组。如何将这个字节数组转储到jpg并在其上写入canavas然后将其保存在SD卡上？

欢迎任何想法。感谢。

Answer 1

使用BitmapFactory.decodeByteArray()获取Bitmap，然后使用该位图创建Canvas，并在那里绘制文字。最后使用Bitmap.compress()保存：

Bitmap bmp = BitmapFactory.decodeByteArray(myArray, 0, myArray.length).copy(Bitmap.Config.RGBA_8888, true); //myArray is the byteArray containing the image. Use copy() to create a mutable bitmap. Feel free to change the config-type. Consider doing this in two steps so you can recycle() the immutable bitmap.
Canvas canvas = new Canvas(bmp);
canvas.drawText("Hello Image", xposition, yposition, textpaint); //x/yposition is where the text will be drawn. textpaint is the Paint object to draw with.

OutputStream os = new FileOutputStream(dstfile); //dstfile is a File-object that you want to save to. You probably need to add some exception-handling here.
bmp.compress(CompressFormat.JPG, 100, os); //Output as JPG with maximum quality.
os.flush();
os.close();//Don't forget to close the stream.

Answer 2

1. 使用BitmapFactory解码字节数组
   1. 创建Canvas
   2. 在其上绘制text
   3. Save您的位图到SD storage

希望这有帮助。