XML布局代码
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.tomes.paint.MainActivity" > <ImageView android:id="@ id/iv_drawingBoard"android:layout_width="wrap_content"android:layout_height="wrap_content"android:src="@drawable/bg"/></RelativeLayout>Java代码
public void init() { Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.bg); copyBitmap = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig()); paint = new Paint(); canvas = new Canvas(copyBitmap); Matrix matrix=new Matrix(); canvas.drawBitmap(bitmap, matrix, paint); imageView = (ImageView) findViewById(R.id.iv_drawingBoard); imageView.setImageBitmap(copyBitmap);imageView.setOnTouchListener(new OnTouchListener() {@SuppressLint("ClickableViewAccessibility")@Overridepublic boolean onTouch(View v, MotionEvent event) { int action = event.getAction(); switch (action) { case MotionEvent.ACTION_DOWN: startX=event.getX(); startY=event.getY();break; case MotionEvent.ACTION_MOVE:float currentX=event.getX();float currentY=event.getY();canvas.drawLine(startX, startY, currentX, currentY, paint);imageView.setImageBitmap(copyBitmap);startX=currentX;startY=currentY;break; case MotionEvent.ACTION_UP:break; } return true;} });}源码下载:点击这里