Matrix 旋转图片,该怎么解决

Matrix xMatrix = new Matrix();
        xMatrix.set(mBaseMatrix);
        xMatrix.setRotate(-90);
        setImageMatrix(xMatrix);
        float v[] = new float[9];
        xMatrix.getValues(v);
        mBaseMatrix.setValues(v);

public class BeadplateMiddle extends View {  
    private Bitmap mBitmap = null;//声明Bitmap对象  
    private int x  = 300;  
    private int y = 100;  
    //private float angleA = 0.0f;//声明轴心A转动  
    private float angleB = 0.0f;//声明轴心B转动角度  
    private Matrix mMatrix = new Matrix();//构建矩阵Matrix对象  
    public BeadplateMiddle(Context context) {  
        super(context);  
        //装载资源  
        mBitmap =((BitmapDrawable) getResources().getDrawable(R.drawable.bedplate)).getBitmap();      
        //开启线程  
        new Thread(new DrawThread()).start();  
    }  
    //系统IOC开始绘制  
    @Override  
    protected void onDraw(Canvas canvas) {  
        super.onDraw(canvas);  
        Paint mPaint = new Paint();  
        mPaint.setColor(Color.RED);  
        mPaint.setAntiAlias(true);  
        canvas.drawCircle(x, y, 12, mPaint);  
        mMatrix = getMyMatrix(mMatrix,angleB, x, y);  
        canvas.drawBitmap(mBitmap, mMatrix, null);  
    }  
    /**
     * 动态构建旋转矩阵Matrix对象
     * @param matrix  需要计算的矩阵
     * @param canvas  画布
     * @param degrees 图片旋转的角度，正值为顺时针，负值为逆时针
     * @param pivotX  轴心的X坐标
     * @param pivotY  轴心的Y坐标
     */  
    private Matrix getMyMatrix(Matrix matrix ,float degrees,int pivotX , int pivotY ){  
        //重置Matrix  
        matrix.reset();  
        float cosValue = (float) Math.cos(Math.PI/(180/degrees));    
        float sinValue = (float) Math.sin(Math.PI/(180/degrees));    
        //设置旋转矩阵值  
        matrix.setValues(    
                new float[]{    
                        cosValue, -sinValue, pivotX,    
                        sinValue, cosValue, pivotY,    
                        0, 0, 1});  
        return matrix;  
    }  
    @Override  
    public boolean onKeyDown(int keyCode, KeyEvent event) {  
        if(keyCode == KeyEvent.KEYCODE_DPAD_LEFT){  
            x --;  
        }else if(keyCode == KeyEvent.KEYCODE_DPAD_RIGHT){  
            x ++;  
        }else if(keyCode == KeyEvent.KEYCODE_DPAD_UP){  
            y --;  
        }else if(keyCode == KeyEvent.KEYCODE_DPAD_DOWN){  
            y ++;  
        }else if(keyCode == KeyEvent.KEYCODE_DPAD_CENTER){  
            angleB ++;  
        }  
        return true;  
    }  
    private class DrawThread implements Runnable{  
        @Override  
        public void run() {  
            while(!Thread.currentThread().isInterrupted()){  
                try {  
                    Thread.sleep(500);  
                } catch (Exception e) {  
                    Thread.currentThread().interrupt();  
                }  
                //使用PostInvalidate可以直接在线程中更新视图  
                postInvalidate();  
            }  
        }  
    }  
}

------解决方案--------------------

#4楼的意思是是像这样

Java code

Matrix xMatrix = new Matrix();
while(true)
{
        xMatrix.set(mBaseMatrix);
        xMatrix.setRotate(-90);
        setImageMatrix(xMatrix);
        float v[] = new float[9];
        xMatrix.getValues(v);
        mBaseMatrix.setValues(v);
}