在jpg圖像android上繪制文本

Question

我在里面有一個jpg圖像作為字節數組。 我如何將這個字節數組轉儲到jpg並在其上寫入canavas然后將其保存在SD卡上？

歡迎任何想法。 謝謝。

Answer 1

使用BitmapFactory.decodeByteArray()獲取Bitmap ，然后使用該位圖創建一個Canvas ，並在那里繪制文本。 最后使用Bitmap.compress()保存它：

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解碼字節數組
   1. 創建一個畫布
   2. 在上面繪制文字
   3. 將位圖保存到SD存儲

希望這可以幫助。