帆布擦除位code机器人 [英] canvas erase bitmap code android
问题描述
我使用低于code到擦除触摸事件从帆布位。
I am using below code to erase bitmap from canvas on touch event.
它的正常工作中的Android 2.3,但4.0它告诉我,而不是删除位图黑点。
it's working fine in android 2.3 but in 4.0 it show me black spot instead of erasing bitmap.
任何人都可以提供帮助。
anyone can help.
公共类DemoTouch延伸活动{
public class DemoTouch extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new TouchView(this));
}
class TouchView extends View {
Bitmap bgr;
Bitmap overlayDefault;
Bitmap overlay;
Paint pTouch;
int X = -100;
int Y = -100;
Canvas c2;
public TouchView(Context context) {
super(context);
bgr = BitmapFactory.decodeResource(getResources(), R.drawable.a1);
overlayDefault = BitmapFactory.decodeResource(getResources(),
R.drawable.a2);
overlay = BitmapFactory.decodeResource(getResources(),
R.drawable.a2).copy(Config.ARGB_4444, true);
c2 = new Canvas(overlay);
pTouch = new Paint(Paint.ANTI_ALIAS_FLAG);
pTouch.setXfermode(new PorterDuffXfermode(Mode.CLEAR));
pTouch.setColor(Color.TRANSPARENT);
pTouch.setMaskFilter(new BlurMaskFilter(15, Blur.NORMAL));
pTouch.setAntiAlias(true);
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN: {
X = (int) ev.getX();
Y = (int) ev.getY();
invalidate();
break;
}
case MotionEvent.ACTION_MOVE: {
X = (int) ev.getX();
Y = (int) ev.getY();
invalidate();
break;
}
case MotionEvent.ACTION_UP:
break;
}
return true;
}
@Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
// draw background
canvas.drawBitmap(bgr, 0, 0, null);
// copy the default overlay into temporary overlay and punch a hole
// in it
// c2.drawBitmap(overlayDefault, 0, 0, null); // exclude this line
// to
// show all as you draw
c2.drawCircle(X, Y, 20, pTouch);
// draw the overlay over the background
canvas.drawBitmap(overlay, 0, 0, null);
}
}
}
推荐答案
有一个在我的这个方法。视图 EditImageView
是一个自定义的的ImageView
,我还申请了擦除功能。直到我申请低于code中的if语句里面我有同样的问题。能解决问题3.0及以上
Have a look at this method of mine. The view EditImageView
is a custom ImageView
that I also applied that erase function to. I had the same problem until I applied the code below inside the if statement. That fixes the problem for 3.0 and up
/**
* Sets the image to the view in the content view
* @param view
*/
private void setImageView(EditImageView view) {
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
view.setLayoutParams(params);
// #### THIS IS THE IMPORTANT PART ######
if (Build.VERSION.SDK_INT >= 11) {
view.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}
LinearLayout main = (LinearLayout) findViewById(R.id.galleryImage);
main.removeAllViews();
main.addView(view);
}
修改
您也许可以做这样的事情在你的code。
You can probably do something like this in your code.
public TouchView(Context context) {
super(context);
// This should fix it from 3.0 and up
if (Build.VERSION.SDK_INT >= 11) {
setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}
bgr = BitmapFactory.decodeResource(getResources(), R.drawable.a1);
overlayDefault = BitmapFactory.decodeResource(getResources(),
R.drawable.a2);
overlay = BitmapFactory.decodeResource(getResources(),
R.drawable.a2).copy(Config.ARGB_4444, true);
c2 = new Canvas(overlay);
pTouch = new Paint(Paint.ANTI_ALIAS_FLAG);
pTouch.setXfermode(new PorterDuffXfermode(Mode.CLEAR));
pTouch.setColor(Color.TRANSPARENT);
pTouch.setMaskFilter(new BlurMaskFilter(15, Blur.NORMAL));
pTouch.setAntiAlias(true);
}
希望这可以帮助你。
Hope this also helps you
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