運動事件android上的矩形 - 變化寬度和高度？

我需要根據ACTION_MOVE從畫布中心繪製矩形。運動事件android上的矩形 - 變化寬度和高度？

我試過這樣

public class CustomRectangle extends View { 

private Bitmap bitTopLeft; 
private Bitmap bitTopRight; 
private Bitmap bitBottomLeft; 
private Bitmap bitBottomRight; 
private Paint rectAnglePaint; 
private Context context; 
private Paint bitmapPaint; 
private Rect rect; 
private int maxX; 
private int maxY; 
private int centerX; 
private int centerY; 
private Paint canvasPaint; 

public CustomRectangle(Context context) { 
    super(context); 
    this.context = context; 
    Init(); 
} 

private void Init() { 
    bitTopLeft = BitmapFactory.decodeResource(context.getResources(), 
      R.drawable.squarsmall); 
    bitTopRight = BitmapFactory.decodeResource(context.getResources(), 
      R.drawable.squarsmall); 
    bitBottomLeft = BitmapFactory.decodeResource(context.getResources(), 
      R.drawable.squarsmall); 
    bitBottomRight = BitmapFactory.decodeResource(context.getResources(), 
      R.drawable.squarsmall); 

    rectAnglePaint = new Paint(); 
    rectAnglePaint.setColor(Color.GREEN); 

    rectAnglePaint.setStrokeWidth(5); 
    rectAnglePaint.setStyle(Paint.Style.STROKE); 

    rectAnglePaint = new Paint(); 
    rectAnglePaint.setColor(Color.GREEN); 

    rectAnglePaint.setStrokeWidth(5); 
    rectAnglePaint.setStyle(Paint.Style.STROKE); 

    bitmapPaint = new Paint(); 
    bitmapPaint.setColor(Color.BLACK); 
    rect = new Rect(); 

    Display display = ((Activity) context).getWindowManager() 
      .getDefaultDisplay(); 
    Point size = new Point(); 
    display.getSize(size); 
    maxX = size.x; 
    maxY = size.y; 

    centerX = maxX/2; 
    centerY = maxY/2; 

    rect.left = centerX/2 + bitBottomRight.getWidth()/2; 
    rect.top = centerY/2 + bitBottomRight.getWidth()/2; 
    rect.right = centerX + centerX/2 + bitBottomRight.getWidth()/2; 
    rect.bottom = centerY + centerY/2 + bitBottomRight.getWidth()/2; 

    canvasPaint = new Paint(); 
    canvasPaint.setColor(Color.TRANSPARENT); 
} 

@Override 
protected void onDraw(Canvas canvas) { 
    canvas.drawPaint(canvasPaint); 
    // Path p = new Path(); 
    canvas.drawBitmap(bitTopLeft, 
      rect.left - bitBottomRight.getWidth()/2, rect.top 
        - bitBottomRight.getWidth()/2, bitmapPaint); 
    canvas.drawBitmap(bitTopRight, rect.right - bitBottomRight.getWidth() 
      /2, rect.top - bitBottomRight.getWidth()/2, bitmapPaint); 
    canvas.drawBitmap(bitBottomLeft, rect.left - bitBottomRight.getWidth() 
      /2, rect.bottom - bitBottomRight.getWidth()/2, bitmapPaint); 
    canvas.drawBitmap(bitBottomRight, 
      rect.right - bitBottomRight.getWidth()/2, rect.bottom 
        - bitBottomRight.getWidth()/2, bitmapPaint); 

    canvas.drawRect(rect, rectAnglePaint); 
} 

@Override 
public boolean onTouchEvent(MotionEvent event) { 
    switch (event.getAction()) { 
    case MotionEvent.ACTION_DOWN: 

     invalidate(); 
     break; 
    case MotionEvent.ACTION_MOVE: 

     int currentx = (int) event.getX(); 
     int currenty = (int) event.getY(); 
     Calculatingpoint(currentx, currenty); 

     break; 

    case MotionEvent.ACTION_UP: 

     break; 
    default: 
     break; 
    } 
    return true; 
} 

private void Calculatingpoint(int x, int y) { 
    if (x < maxX && y < maxY) { 
     int dx = 0; 
     int dy = 0; 

     dx = rect.right - x; 
     dy = rect.bottom - y; 

     // this is working perfect when i touched right bottom. 
     rect.inset(dx, dy); 

     invalidate(); 
    } 
} 
}

但是當我接觸其他角落的矩形消失。

我需要從中心點繪製矩形。我需要根據觸摸增加或減少寬度和高度。

請指教，如何做到這一點。請給我樣品。

來源

2015-04-20 prakash

請幫我做到這一點.. – prakash

最後我得到了解決方案...我會發布答案.. – prakash

我從用戶觸摸位置找到方向，下面是我更新的代碼。

public class CustomRectangle extends View { 

private Bitmap bitTopLeft; 
private Bitmap bitTopRight; 
private Bitmap bitBottomLeft; 
private Bitmap bitBottomRight; 
private Paint rectAnglePaint; 
private Context context; 
private Paint bitmapPaint; 
private Rect rect; 
private int maxX; 
private int maxY; 
private int centerX; 
private int centerY; 
private Paint canvasPaint; 
private String direction; 

public CustomRectangle(Context context) { 
    super(context); 
    this.context = context; 
    Init(); 
} 

private void Init() { 
    bitTopLeft = BitmapFactory.decodeResource(context.getResources(), 
      R.drawable.squarsmall); 
    bitTopRight = BitmapFactory.decodeResource(context.getResources(), 
      R.drawable.squarsmall); 
    bitBottomLeft = BitmapFactory.decodeResource(context.getResources(), 
      R.drawable.squarsmall); 
    bitBottomRight = BitmapFactory.decodeResource(context.getResources(), 
      R.drawable.squarsmall); 

    rectAnglePaint = new Paint(); 
    rectAnglePaint.setColor(Color.GREEN); 

    rectAnglePaint.setStrokeWidth(5); 
    rectAnglePaint.setStyle(Paint.Style.STROKE); 

    rectAnglePaint = new Paint(); 
    rectAnglePaint.setColor(Color.GREEN); 

    rectAnglePaint.setStrokeWidth(5); 
    rectAnglePaint.setStyle(Paint.Style.STROKE); 

    bitmapPaint = new Paint(); 
    bitmapPaint.setColor(Color.BLACK); 
    rect = new Rect(); 

    Display display = ((Activity) context).getWindowManager() 
      .getDefaultDisplay(); 
    Point size = new Point(); 
    display.getSize(size); 
    maxX = size.x; 
    maxY = size.y; 

    centerX = maxX/2; 
    centerY = maxY/2; 

    rect.left = centerX/2 + bitBottomRight.getWidth()/2; 
    rect.top = centerY/2 + bitBottomRight.getWidth()/2; 
    rect.right = centerX + centerX/2 + bitBottomRight.getWidth()/2; 
    rect.bottom = centerY + centerY/2 + bitBottomRight.getWidth()/2; 

    canvasPaint = new Paint(); 
    canvasPaint.setColor(Color.TRANSPARENT); 
} 

@Override 
protected void onDraw(Canvas canvas) { 
    canvas.drawPaint(canvasPaint); 
    // Path p = new Path(); 
    canvas.drawBitmap(bitTopLeft, 
      rect.left - bitBottomRight.getWidth()/2, rect.top 
        - bitBottomRight.getWidth()/2, bitmapPaint); 
    canvas.drawBitmap(bitTopRight, rect.right - bitBottomRight.getWidth() 
      /2, rect.top - bitBottomRight.getWidth()/2, bitmapPaint); 
    canvas.drawBitmap(bitBottomLeft, rect.left - bitBottomRight.getWidth() 
      /2, rect.bottom - bitBottomRight.getWidth()/2, bitmapPaint); 
    canvas.drawBitmap(bitBottomRight, 
      rect.right - bitBottomRight.getWidth()/2, rect.bottom 
        - bitBottomRight.getWidth()/2, bitmapPaint); 

    canvas.drawRect(rect, rectAnglePaint); 
} 
float x1, x2, y1, y2, dx, dy; 

@Override 
public boolean onTouchEvent(MotionEvent event) { 
    switch (event.getAction()) { 
    case MotionEvent.ACTION_DOWN: 
     x1 = event.getRawX(); 
     y1 = event.getRawY(); 
     invalidate(); 
     break; 
    case MotionEvent.ACTION_MOVE: 
     x2 = event.getRawX(); 
     y2 = event.getRawY(); 
     int currentx = (int) event.getX(); 
     int currenty = (int) event.getY(); 
     Calculatingpoint(currentx, currenty); 

     break; 

    case MotionEvent.ACTION_UP: 

     break; 
    default: 
     break; 
    } 
    return true; 
} 

private void Calculatingpoint(int x, int y) { 
    if (x2 < maxX && y2 < maxY) { 
     int dx = 0; 
     int dy = 0; 

     // dx = rect.right - (int)x2 ; 
     // dy = (int)y2 - rect.top ; 
     // 
     // Log.e("dx", ""+dx); 
     // Log.e("dy", ""+dy); 

     boolean isLeft = false; 
     boolean isTop = false; 

     if (x2 > maxX/2) { 
      direction = "right"; 
      isLeft = false; 
     } else { 
      direction = "left"; 
      isLeft = true; 
     } 

     if (y2 > maxY/2) { 
      direction = "bottom"; 
      isTop = false; 
     } else { 
      direction = "top"; 
      isTop = true; 
     } 

     if (!isLeft && !isTop) { 
      dx = rect.right - (int) x2; 

      dy = rect.bottom - (int) y2; 
     } 

     if (isLeft && !isTop) { 
      dx = (int) x2 - rect.left; 
      dy = rect.bottom - (int) y2; 
     } 

     if (isLeft && isTop) { 
      dx = (int) x2 - rect.left; 
      dy = (int) y2 - rect.top; 
     } 

     if (!isLeft && isTop) { 
      dx = rect.right - (int) x2; 
      dy = (int) y2 - rect.top; 
     } 
// this will perfect 
     rect.inset(dx, dy); 
     invalidate(); 

    } 
} 
}

來源

2015-04-22 15:48:11 prakash

運動事件android上的矩形 - 變化寬度和高度？

回答

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