public class CanvasActivity extends AppCompatActivity {
String TAG="test2";
ImageView imageView;
Canvas canvas;
Paint paint;
int startX=0;
int startY=0;
Bitmap bitmap;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
imageView=(ImageView)findViewById(R.id.imageView);
init();
}
private void init() {
//创建空白画布
= Bitmap.createBitmap Bitmap (getWindowManager () getDefaultDisplay () getWidth (), getWindowManager () getDefaultDisplay () getHeight (), Bitmap.Config.ARGB_4444....);
Canvas the Canvas new new = (Bitmap);
// set the canvas background color
canvas.drawRGB (0xAA, 0xAA, 0xAA);
Paint new new = the Paint ();
// set the brush width
paint.setStrokeWidth (10);
// set brush color
paint.setColor (0xFFFF0000);
imageView.setImageBitmap (Bitmap );
imageView.setOnTouchListener (new new View.OnTouchListener () {
@Override
public Boolean OnTouch (View V, the MotionEvent Event) {
IF (event.getAction () == MotionEvent.ACTION_DOWN) {
Log.e (the TAG, "ACTION_DOWN0");
= startX (int) (event.getX ());
the startY is = (int) (event.getY ());
} the else IF (event.getAction () == MotionEvent.ACTION_MOVE) {
Log.e(TAG,"ACTION_MOVE startX="+startX +" startY="+startY +" v.getX()="+(int)event.getX() +" v.getY()="+(int)event.getY());
canvas.drawLine(startX,startY,(int)event.getX(),(int)event.getY(),paint);
startX=(int)(event.getX());
startY=(int)(event.getY());
imageView.setImageBitmap(bitmap);
}else if(event.getAction()==MotionEvent.ACTION_UP){
Log.e(TAG,"ACTION_UP");
try {
Path = Environment.getExternalStorageDirectory String () + + File.separator "test.png";
FileOutputStream fileOutputStream = new FileOutputStream(path);
bitmap.compress (Bitmap.CompressFormat.PNG, 100, FileOutputStream); // save the image
canvas.drawRGB (0xAA, 0xAA, 0xAA) ; / / Clear data drawing board
imageView.setImageBitmap (Bitmap);
} the catch (Exception EX) {
}
}
return to true;
}
});
}