Question

我有一个项目，我正在尝试绘制矩形以填充屏幕

MainActivity.java

public class MainActivity extends Activity  {

     private int vScreenHeight, vScreenWidth;          

     private int vLeftPos = 0;
     private int vTopPos = 0;
     private int vRightPos = 154;
     private int vBottomPos = 154;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          vGetScreenHeightAndWidth();

          while(vTopPos < vScreenHeight) {
              while(vLeftPos < vScreenWidth) {
                 RectView rectView = new RectView(getApplicationContext(), vLeftPos, vTopPos, vRightPos, vBottomPos);
                 vLeftPos +=  154;
                 vRightPos += 154;
                 setContentView(rectView);
             }
             vLeftPos = 0;
             vTopPos += 154;
             vRightPos = 154;
             vBottomPos += 154;
         }
     }

     private void vGetScreenHeightAndWidth() {
          Display display = getWindowManager().getDefaultDisplay();
          Point size = new Point();
          display.getSize(size); // this will work only in API level 13 above.
          vScreenWidth  = size.x;
          vScreenHeight = size.y;
     }
 }

RectView.java

public class RectView extends View implements OnClickListener
{

    private int vLeftPos;
    private int vTopPos;
    private int vRightPos;
    private int vBottomPos;

    Rect r;

    private Paint paint = new Paint();

    private final String TAG = "Canvas Application";

    public RectView(Context pAppContext, int pLeftPos, int pTopPos, int pRightPos, int pBottomPos) 
    {
        super(pAppContext);

        vLeftPos = pLeftPos;
        vTopPos = pTopPos;
        vRightPos = pRightPos;
        vBottomPos = pBottomPos;

        r = new Rect(); 

        this.setOnClickListener(this);
    }           

    public void onDraw(Canvas pCanvasObj)
    {
        r.set(vLeftPos, vTopPos, vRightPos, vBottomPos);
        paint.setStyle(Paint.Style.FILL);
        paint.setColor(Color.RED); 
        pCanvasObj.drawRect(r, paint);      
        paint.setStyle(Paint.Style.STROKE);
        paint.setColor(Color.BLACK);
        pCanvasObj.drawRect(r, paint);  

    }

    @Override
    public void onClick(View v) 
    {       
        Toast.makeText(null, "tapped", Toast.LENGTH_SHORT).show();      
    }
}

在这个Activity中，我正在计算矩形的位置并创建一个RectView对象来绘制矩形。

我无法理解我做错了什么？

Answer 1

问题出在RectView。你可以试试这个：

public class RectView extends View {

private RectF rect;
private Paint paint;

/**
 * @param context
 */
public RectView(Context context) {
    super(context);
    paint=new Paint();
    paint.setColor(Color.RED);
    rect=new RectF();
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    rect.set(0, 0, MeasureSpec.getSize(widthMeasureSpec), MeasureSpec.getSize(heightMeasureSpec));
    setMeasuredDimension(MeasureSpec.getSize(widthMeasureSpec), MeasureSpec.getSize(heightMeasureSpec));
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    canvas.drawRect(rect, paint);
}

drawrect（）在Android中不起作用

1 个答案: