问题上的布局图的位图

Question

我的onCreate编程方式创建布局：

new Handler().postDelayed(new Runnable() { 

     @Override 
     public void run() { 
      myView = new MyView(SketchActivity.this, layout.getWidth(), layout.getHeight()); 

      layout2.addView(myView); 
      layout2.bringToFront(); 

     } 
    }, 50); 

其中i创建（可变的？）位图查看：

public MyView(Context c, int width, int height) { 
     super(c); 

     WindowManager wm = (WindowManager) c.getSystemService(Context.WINDOW_SERVICE); 
     Display display = wm.getDefaultDisplay(); 
     int w = display.getWidth(); // deprecated 
     int h = display.getHeight(); 
     setFocusable(true); 
     setBackgroundResource(R.drawable.download); 

     // setting paint 
     mPaint = new Paint(); 
     mPaint.setAlpha(0); 
     mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN)); 
     mPaint.setAntiAlias(true); 

     // getting image from resources 
     Resources r = this.getContext().getResources(); 

     Bitmap bm = BitmapFactory.decodeResource(getResources(), R.drawable.smoke); 

     // converting image bitmap into mutable bitmap 

     bitmap = bm.createBitmap(w, h, Config.ARGB_8888); 
     mCanvas = new Canvas(); 
     mCanvas.setBitmap(bitmap); // drawXY will result on that Bitmap 
     mCanvas.drawBitmap(bm, 0, 0, null); 

    } 

我OnDraw函数：

@Override 
    protected void onDraw(Canvas canvas) { 
     mCanvas.drawCircle(x, y, r, mPaint); 

     canvas.drawBitmap(bitmap, 0, 0, null); 

     super.onDraw(canvas); 

    } 

的onTouchEvent：

@Override 
    public boolean onTouchEvent(MotionEvent event) { 
     x = (int) event.getX(); 
     y = (int) event.getY(); 

     r = 20; 
     // Atlast invalidate canvas 
     invalidate(); 

     return true; 
    } 

没有LogCat错误 问题出在myView中。当我创建位图位图= bm.createBitmap（w，h，Config.ARGB_8888）;如果我把w而不是w，h（屏幕的宽度和高度）一个小数字例如：bitmap = bm.createBitmap（20，20，Config.ARGB_8888）;它创建了一个小图片。但是如果我把w和h放在一起，那么就不是画出所有的布局，而只是画出一小部分。 （即使我尝试：bitmap = bm.createBitmap（800，1080，Config.ARGB_8888）;它仍然占用一小部分，而不是所有的屏幕，我应该怎么做？

Answer 1

这解决了这个问题：

public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) { 
    int width = bm.getWidth(); 
    int height = bm.getHeight(); 
    float scaleWidth = ((float) newWidth)/width; 
    float scaleHeight = ((float) newHeight)/height; 
    // CREATE A MATRIX FOR THE MANIPULATION 
    Matrix matrix = new Matrix(); 
    // RESIZE THE BIT MAP 
    matrix.postScale(scaleWidth, scaleHeight); 
    // RECREATE THE NEW BITMAP 
    Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, false); 
    return resizedBitmap; 
} 

public MyView(Context c, int width, int height) { 
     super(c); 

     WindowManager wm = (WindowManager) c.getSystemService(Context.WINDOW_SERVICE); 
     Display display = wm.getDefaultDisplay(); 
     int w = display.getWidth(); // deprecated 
     int h = display.getHeight(); 
     setFocusable(true); 
     setBackgroundResource(R.drawable.download); 

     // setting paint 
     mPaint = new Paint(); 
     mPaint.setAlpha(0); 
     mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN)); 
     mPaint.setAntiAlias(true); 
     mPaint.setMaskFilter(new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL)); 

     // getting image from resources 
     Resources r = this.getContext().getResources(); 

     Bitmap bm = BitmapFactory.decodeResource(getResources(), R.drawable.smoke); 
     Bitmap bm2 = getResizedBitmap(bm, h, w); 

     // converting image bitmap into mutable bitmap 

     bitmap = bm2.createBitmap(w, h, Config.ARGB_8888); 
     mCanvas = new Canvas(); 
     mCanvas.setBitmap(bitmap); // drawXY will result on that Bitmap 
     mCanvas.drawBitmap(bm2, 0, 0, null); 

    } 

Answer 2

看起来像是回收您Bitmap somwhere中的代码。有个问题。

是的，你应该recycle它，但它始终是一个有点冒险。

编辑

看起来你正在绘制到Bitmap。如果这不是你想要做的，那么你不应该打电话给onDraw手动。如果您想重新绘制视图，请拨打invalidate()。

Answer 3

您需要添加这样一个Options数据：

Options options = new Options(); 
options.isMutable = true; // works from api 11 

mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.smoke, options);