java在Jpg图像上绘制直线或矩形，并将其保存在Android应用程序中

Question

我有坐标，我想在保存在安卓设备中的jpg图像上画一条直线或矩形，然后保存新文件
可能吗？我试图告诉我们ImageIO但它在安卓系统中不可用，或者出了问题，无法接受
有什么想法或代码吗

Answer 1

这就是我如何在现有的JPEG上绘制一个绿色方框的方法

Bitmap workingBitmap = BitmapFactory.decodeFile( mFullFilePath );
Bitmap mutableBitmap = workingBitmap.copy(Bitmap.Config.ARGB_8888, true);

// bitmap needs to be mutable
Canvas tmpCanvas = new Canvas(mutableBitmap);

// setup paint parameters
Paint paint = new Paint();
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth( 5 );
paint.setColor(Color.GREEN);

// Rect object was passed; use below to test
// Rect rect = new Rect( 0, 0, 10, 10 );
tmpCanvas.drawRect(rect, paint);

// write the updated file out as a JPG
writeExternalToCache( mutableBitmap, mFullFilePath );

另见：

• https://stackoverflow.com/a/13119762/3474698
• https://stackoverflow.com/a/8801391/3474698