Question

这是我到目前为止尝试的代码..

package com.gtxradeon.brands;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;



public class Panel extends SurfaceView implements SurfaceHolder.Callback {
    private CanvasThread canvasthread;
    public Paint paint;
    private Bitmap scaled;

    public Panel(Context context, AttributeSet attrs) {
        super(context, attrs);
        // TODO Auto-generated constructor stub
        getHolder().addCallback(this);
        canvasthread = new CanvasThread(getHolder(), this);
        setFocusable(true);
        paint = new Paint();
    }

    public Panel(Context context) {
        super(context);
        getHolder().addCallback(this);

        setFocusable(true);

    }

    @Override
    public void onDraw(Canvas canvas) {

        //paint.setARGB(255, 255, 0, 0);
        // canvas.drawColor(Color.BLACK);
//      canvas.drawCircle(500f, 500f, 30, paint);

        Bitmap bmp = BitmapFactory.decodeResource(getResources(),R.drawable.mapmarker);
        canvas.drawBitmap(bmp , 250f, 250f, null);   

    }

    public void surfaceChanged(SurfaceHolder holder, int format, int width,
            int height) {
        // TODO Auto-generated method stub

    }

    public void surfaceCreated(SurfaceHolder holder) {
        // TODO Auto-generated method stub
//      Bitmap background = BitmapFactory.decodeResource(getResources(), R.drawable.grocery);
//      float scale = (float) background.getHeight() / (float) getHeight();
//        int newWidth = Math.round(background.getWidth() / scale);
//        int newHeight = Math.round(background.getHeight() / scale);
//        scaled = Bitmap.createScaledBitmap(background, newWidth, newHeight, true);
        canvasthread = new CanvasThread(getHolder(), this);
        canvasthread.setRunning(true);
        canvasthread.start();

    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // TODO Auto-generated method stub
        boolean retry = true;
        canvasthread.setRunning(false);
        while (retry) {
            try {
                canvasthread.join();
                retry = false;
            } catch (InterruptedException e) {
                // we will try it again and again...
            }
        }

    }

}

这是xml文件

<FrameLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <!-- <ImageView
            android:id="@+id/imageView1"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:src="@drawable/grocery" /> -->

        <com.gtxradeon.brands.Panel
            android:id="@+id/SurfaceView01"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

    </FrameLayout>

我已尝试过图像视图，但它不会显示为背景，因为我认为surfaceview位于它之上。

我也尝试将图片设置为android:background="@drawable/bg"之类的背景但仍然没有显示..

我尝试过这个帖子的解决方案Setting image background in SurfaceView, getting black screen 但仍然没有帮助我..

唯一出现的是我在onDraw（）方法中显示的制作者。

Answer 1

在onDraw（）中执行此操作。但是你应该先从工厂创建这个位图。不要在onDraw（）中执行此操作设置SurfaceView以使其on Top of all views behind有一些技巧。但是你应该了解要求并选择更合适的解决方案。

Answer 2

还可以使用setFormat设置持有者，就像我为透明表面视图所做的那样：

SurfaceHolder holder = getHolder();
holder.addCallback(this);
holder.setFormat(PixelFormat.OPAQUE);

// set the compass background as transparent
// holder.setFormat(PixelFormat.TRANSLUCENT);

Answer 3

你需要做一些小问题才能在SurfaceView中使用任何后台工作，如下所示：

覆盖setBackground和setBackgroundDrawable方法

   Drawable background

   @Override
   public void setBackgroundDrawable(Drawable background) {
      this.background = background;
   }

   @Override
   public void setBackground(Drawable background) {
      this.background = background;
   }

不要忘记在可绘制的

上拨打setBounds

   @Override
   protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
      super.onLayout(changed, left, top, right, bottom);
      matrix = null;
      if (background != null)
         background.setBounds(left, top, right, bottom);
   }

然后在代码中你锁定，绘制，解锁和发布你添加背景的画布

   Canvas c = holder.lockCanvas();
   if (background != null)
      background.draw(c);

   // do your stuff here

   holder.unlockCanvasAndPost(c);

适用于XML和Java背景。

如何在SurfaceView上设置背景

3 个答案: