这是我的程序代码:如何根据下面的代码清除我的画布?
SingleTouchEvent是我的课
的名称中使用canvas.onDraw但它只能更改背景我累了。我想要的是,清除画布上的另一张图纸。
public class SingleTouchEventView extends View {
private Paint paint = new Paint();
private Path path = new Path();
public SingleTouchEventView(Context context, AttributeSet attrs) {
super(context, attrs);
paint.setAntiAlias(true);
paint.setStrokeWidth(6f);
paint.setColor(Color.GREEN);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
}
它只改变屏幕的颜色。它不会删除画布的前一个内容。
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.BLACK);
canvas.drawPath(path, paint);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float eventX = event.getX();
float eventY = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
path.moveTo(eventX, eventY);
return true;
case MotionEvent.ACTION_MOVE:
path.lineTo(eventX, eventY);
break;
case MotionEvent.ACTION_UP:
// nothing to do
break;
default:
return false;
}
// Schedules a repaint.
invalidate();
return true;
}
}
关闭一个副本http://stackoverflow.com/questions/5729377/android-canvas-how-do-i-clear-delete-contents-of-a-canvas-bitmaps-livin –
哪里会iplace的canvas.onDraw? – user1081908