如何在MFC中使用滑块控件 [英] How to use Slider Control in MFC

问题描述

Hello Everyone，



我在MFC工具的对话框中放置了一个Slider控件。我想要的是当用户移动滑块时，我想要用户将滑块放在轨迹栏上的位置/值（在运行时）并将该值发送到USB端口以及在编辑框中显示该值。

我想在用户移动并放置滑块时立即获取值。如何在运行时获取值？

请给我一些建议。

Hello Everyone,

I have placed a Slider control on the dialog box from the MFC Tools. What I want is when the user moves the slider, I want the position / value where user has placed the slider on track bar (at runtime) and Send that value to USB Port as well as display that value in an edit box.
I want the value as soon as user moves and places the slider. How to get the value at runtime?
Please suggest me something.

推荐答案

只需处理 OnHScroll（） 或 OnVScroll（）消息，如滑块通知消息 [ ^ ]。当用户移动滑块并释放鼠标按钮时，会发送 TB_THUMBPOSITION 通知（ nSBCode 滚动处理程序参数）。该位置在 nPos 参数中传递，并在 pScrollBar 参数中指向滑块控件的指针（必须进行转换）到 CSliderCtrl * ）。



[更新：示例代码]

如果没有到目前为止，将 WM_HSCROLL 处理程序添加到对话框中，并为滑块添加一个成员变量：

Just handle the OnHScroll() or OnVScroll() message as described in Slider notification messages[^]. When the user moves the slider and releases the mouse button, a TB_THUMBPOSITION notification is send (nSBCode parameter of the scroll handler). The position is passed in the nPos parameter and a pointer to the slider control in the pScrollBar parameter (this must be casted to CSliderCtrl*).

[UPDATE: Example code]
If not done so far, add the WM_HSCROLL handler to your dialog and optional a member variable for the slider:

void CMyDlg::OnHScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar)
{
    if (IDC_SLIDER == pScrollBar->GetDlgCtrlID())
    {
        // When there is no member variable and we need to access the control
//      CSliderCtrl* pSlider = reinterpret_cast<CSliderCtrl*>(pScrollBar);
        // Handle event here
        switch (nSBCode)
        {
            case TB_LINEUP:
            case TB_LINEDOWN:
            case TB_PAGEUP:
            case TB_PAGEDOWN:
            case TB_THUMBPOSITION:
            case TB_TOP:
            case TB_BOTTOM:
            case TB_THUMBTRACK:
            case TB_ENDTRACK:
            default:
                break;
        }
        return;
    }
    // Default handling if not a slider control.
    CDialog::OnHScroll(nSBCode, nPos, pScrollBar);
}

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