Question

我正在尝试在android中画线。但是我不满足于因为它没有绘制完整的线条，当我快速移动物体时它绘制了一条虚线，当我慢慢移动物体时它绘制了一条完整的线条.Plaese帮助我为什么会这样。我想要完整的线而不是虚线。我的代码在这里：触摸事件视图：

public boolean onTouch(View view, MotionEvent event) {
    // TODO Auto-generated method stub
    final int X = (int) event.getRawX();
    final int Y = (int) event.getRawY();
    switch (event.getAction() & MotionEvent.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN:
        RelativeLayout.LayoutParams lParams = (RelativeLayout.LayoutParams) view
                .getLayoutParams();

        _xDelta = X - lParams.leftMargin;
        Log.e("ACTION DOWN X", "" + Y + "---" + lParams.leftMargin);
        _yDelta = Y - lParams.topMargin;
        Log.e("ACTION DOWN Y", "" + Y + "---" + lParams.leftMargin);

        break;
    case MotionEvent.ACTION_UP:
        break;
    case MotionEvent.ACTION_POINTER_DOWN:
        break;
    case MotionEvent.ACTION_POINTER_UP:
        break;
    case MotionEvent.ACTION_MOVE:
        RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) view
                .getLayoutParams();
        layoutParams.leftMargin = X - _xDelta;
        Log.e("ACTION Move left margin", "" + (X - _xDelta));
        layoutParams.topMargin = Y - _yDelta;
        Log.e("ACTION Move top margin", "" + (Y - _yDelta));
        layoutParams.rightMargin = -250;
        layoutParams.bottomMargin = -250;

        view.setBackgroundColor(random.nextInt());

        view.setLayoutParams(layoutParams);
        draw = new DrawLine(MainActivity.this, X - _xDelta, Y - _yDelta);
        root.addView(draw);

        break;
    }

    root.invalidate();
    return true;
}

我的绘制方法是这样的：

@Override
    protected void onDraw(final Canvas canvas) {
        // TODO Auto-generated method stub
        super.onDraw(canvas);
        // paint.setColor(random.nextInt());
        paint.setStyle(Style.STROKE);
        paint.setStrokeWidth(4);
        canvas.drawPoint(startX, startY, paint);


    }

我也想知道如何清除所有图纸请帮我解决这个问题。谢谢。

Answer 1

那么当你只绘制点时，你怎么期望画出一条线呢？触摸事件注册/处理速度不够快，无法触发手指触摸的每个新像素。使用路径存储您的点并使用路径中的点绘制线条/路径。

使用drawPoint（）绘制线条

1 个答案: