在不使用javascript的情况下拖动Blazor选择(razor语法)

<div id="selectionArea" draggable="true" @onmousedown="StartDrag" @onmousemove="UpdateSelection" @onmouseup="EndDrag">
    <!-- 可拖动的选择区域 -->
</div>

@code {
    private bool isDragging = false;
    private int startX;
    private int startY;
    private int endX;
    private int endY;

    private void StartDrag(MouseEventArgs e)
    {
        isDragging = true;
        startX = (int)e.ClientX;
        startY = (int)e.ClientY;
    }

    private void UpdateSelection(MouseEventArgs e)
    {
        if (isDragging)
        {
            endX = (int)e.ClientX;
            endY = (int)e.ClientY;

            // 根据起始点和结束点的坐标计算选择区域的大小和位置
            // 更新选择区域的样式或执行其他操作
        }
    }

    private void EndDrag(MouseEventArgs e)
    {
        isDragging = false;

        // 拖动选择结束后的处理逻辑
    }
}