Question

我有两个图像，一个在一个以上，我想在用户擦除它时使上面的图像透明，并且应该显示覆盖的图像...听到的是我的代码

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BlurMaskFilter.Blur;
import android.graphics.BitmapFactory;
import android.graphics.BlurMaskFilter; 
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;

public class StartActivity 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.bgr);
            overlayDefault = BitmapFactory.decodeResource(getResources(),R.drawable.over);
            overlay = BitmapFactory.decodeResource(getResources(),R.drawable.over).copy(Config.ARGB_8888, true);  
            c2 = new Canvas(overlay);

            pTouch = new Paint(Paint.ANTI_ALIAS_FLAG);         
            pTouch.setXfermode(new PorterDuffXfermode(Mode.SRC_OUT)); 
            pTouch.setColor(Color.TRANSPARENT);
            pTouch.setMaskFilter(new BlurMaskFilter(15, Blur.NORMAL));
        }

        @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, 80, pTouch);
            //draw the overlay over the background  
            canvas.drawBitmap(overlay, 0, 0, null);
        }
    }
}

但我收到了错误：

pTouch.setXfermode（new PorterDuffXfermode（Mode.SRC_OUT））;

错误是：

“SRC_OUT无法解析或不是字段”。

Answer 1

关闭，您需要确保您的模式来自正确的包。你应该使用的是：

android.graphics.PorterDuff.Mode

将问题行更改为：

 pTouch.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_OUT));

setXfermode（new PorterDuffXfermode（Mode.SRC_OUT））给出错误

1 个答案: