Android - canvas drawBitmap和不同的分辨率?

时间:2012-10-19 13:10:33

标签: android canvas resolution density-independent-pixel drawbitmap

我有这个问题,例如在画布上绘制两个位图(它是用于动态壁纸)。事实是,前面的小位图应该恰好放在背景位图的正确位置。它当然在模拟器上看起来很好(比方说480x800分辨率)。但是当我在手机上检查它(800x1280 res)时,它不适合正确的位置。

我试过用这个:

    int pixel = 120;
final float scale = getResources().getDisplayMetrics().density;
int dip = (int) (pixel* scale + 0.5f);

而不是硬像素,但它也没有好处。 以下是全班代码:

public class DemoWallpaperService extends WallpaperService {

@Override
public Engine onCreateEngine() {
    return new DemoWallpaperEngine();
}

private class DemoWallpaperEngine extends Engine {
    private boolean mVisible = false;
    private final Handler mHandler = new Handler();

     int x=0,y=0,a=255,i=-1, a1=255, i1=-1;
     float r=0,rs=1;
     float rx1=10, rxs=-1;

     private Matrix mMatrix = new Matrix();
     private Matrix mMatrix1 = new Matrix();
     private Matrix mMatrixRotate1 = new Matrix();
     private Matrix mMatrixRotate2 = new Matrix();

     public Bitmap spaceShip = BitmapFactory.decodeResource(getResources(), R.drawable.spaceship);
     public Bitmap background= BitmapFactory.decodeResource(getResources(), R.drawable.back2short2j);
     public Bitmap wyspa= BitmapFactory.decodeResource(getResources(), R.drawable.wyspa22g);
     public Bitmap ksiezyc = BitmapFactory.decodeResource(getResources(), R.drawable.ksiezyc);
     public Bitmap reflektorfront= BitmapFactory.decodeResource(getResources(), R.drawable.reflektorwyspa);

     private float mPixels;
     private float mPixels1;



    private final Runnable mUpdateDisplay = new Runnable() {
    @Override
    public void run() {
        draw();
    }};



    private void draw() {
       SurfaceHolder holder = getSurfaceHolder();
       Canvas c = null;

       Display d = ((WindowManager)getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
       int wx= d.getWidth();
       int wy= d.getHeight();

       try {
           Runtime.getRuntime().gc();
          c = holder.lockCanvas();
          c.save();

          if (c != null) {

              Paint paintMoon = new Paint();

              if(a1<=15){
                  i1=1;
              }
              else if(a1>=255){
                  i1=-1;
              }
              a1+=5*i1;
              paintMoon.setAlpha(a1);

              c.translate((float)mPixels, 0f);
              c.drawBitmap(background, mMatrix, null);
              c.drawBitmap(ksiezyc, 1027*wx/480,15*wy/800, paintMoon);

              if(rx1<=-15){
                  rxs=1;
              }
              else if(rx1>=15){
                  rxs=-1;
              }
              rx1+=rxs*0.7;

              c.translate((float)mPixels1, 0f);
              //reflektor wyspa back
              mMatrixRotate2.setTranslate(340*wx/480,300*wy/800);
              mMatrixRotate2.preRotate(rx1,reflektorfront.getWidth()/2,20);
              c.drawBitmap(reflektorfront, mMatrixRotate2, null);


              c.drawBitmap(wyspa, mMatrix1, null);

              if(r<=-15){
                  rs=1;
              }
              else if(r>=15){
                  rs=-1;
              }
              r+=rs*0.5;


              mMatrixRotate1.setTranslate(160*wx/480,380*wy/800);

              mMatrixRotate1.preRotate(r,reflektorfront.getWidth()/2,20);

              c.drawBitmap(reflektorfront, mMatrixRotate1, null);


              if(x<c.getWidth()){
              x+=3;}
              else{x=0;}
              if(y<c.getHeight()){
              y+=3;}
              else{y=0;}
              Paint paint = new Paint();


              if(a<=5){
                  i=1;
              }
              else if(a>=255){
                  i=-1;
              }
              a+=10*i;
              paint.setAlpha(a);

              c.drawBitmap(spaceShip,x,y,paint);


                 c.restore();

          }
       } finally {
          if (c != null)
             holder.unlockCanvasAndPost(c);
       }
       mHandler.removeCallbacks(mUpdateDisplay);
       if (mVisible) {
           mHandler.postDelayed(mUpdateDisplay, 10);
       }
    }
    @Override
    public void onOffsetsChanged(float xOffset, float yOffset,
             float xStep, float yStep, int xPixels, int yPixels){

        super.onOffsetsChanged(xOffset, yOffset, xStep, yStep, xPixels, yPixels);                   
         mPixels = xPixels*7/4;

         mPixels1 = 500+xPixels;

            draw();
    }



    @Override
    public void onVisibilityChanged(boolean visible) {
        mVisible = visible;
        if (visible) {
            draw();
        } else {
            mHandler.removeCallbacks(mUpdateDisplay);
        }
    }

     @Override
      public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {

         super.onSurfaceChanged(holder, format, width, height);

         float w = background.getWidth();
         float h = background.getHeight();
         float s = height / (float)h;
         float z = height / (float)h;
         mMatrix.reset();
         mMatrix1.reset();
         mMatrixRotate1.reset();
         mMatrixRotate2.reset();

         mMatrix.setScale(s, s);
         mMatrix1.setScale(z, z);
         mMatrixRotate1.setScale(s, s);

         draw();
      }

    @Override
    public void onSurfaceDestroyed(SurfaceHolder holder) {
        super.onSurfaceDestroyed(holder);
        mVisible = false;
        mHandler.removeCallbacks(mUpdateDisplay);
    }


    @Override
     public void onCreate(SurfaceHolder surfaceHolder) {
         super.onCreate(surfaceHolder);

         setTouchEventsEnabled(false);
     }

    @Override
    public void onDestroy() {
         super.onDestroy();
         mVisible = false;
         mHandler.removeCallbacks(mUpdateDisplay);
    }
}    

所以如果可以,请帮助任何人。

2 个答案:

答案 0 :(得分:0)

使用ViewTreeObserver测量视图/屏幕尺寸,并使用生成的坐标放置位图。

以下是衡量布局宽度和高度的示例代码

final RelativeLayout mainLayout = (RelativeLayout) findViewById(R.id.main_layout);
        ViewTreeObserver vto = mainLayout.getViewTreeObserver();
        vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                final int viewWidth = mainLayout.getMeasuredWidth();
                final int viewHeight = mainLayout.getMeasuredHeight();
                if (Constants.LOG_ENABLED) {
                    Log.i(TAG, "Width: " + viewWidth);
                    Log.i(TAG, "Height: " + viewHeight);
                }
                /**
                 * Delete tree observer
                 */
                ViewTreeObserver obs = mainLayout.getViewTreeObserver();
                obs.removeGlobalOnLayoutListener(this);


}
        });

答案 1 :(得分:0)

  1. 获取密度

    DisplayMetrics metrics;
    metrics = new DisplayMetrics();
    metrics = new DisplayMetrics();
    getWindowManager().getDefaultDisplay().getMetrics(metrics);
    float density = metrics.density;
    
  2. 像这样申请

    Canvas canvas = new Canvas(bitmap);
    canvas.drawBitmap(ksiezyc, density * wx,density * wy, paintMoon);
    
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