In可以在Toolbox的"所有Windows窗体"区域中找到Visual Studio 2017，
TrackBar 。您也可以右键单击打开的工具箱，然后选择"选择项目..."，您可以在其中找到并启用
TrackBar 控件。检查是否可以在您的版本中完成此操作。

In Visual Studio 2017, TrackBar can be found in the "All Windows Forms" area of Toolbox. You can also right-click the opened Toolbox, then "Choose Items…", where you can find and enable the TrackBar control. Check if this can be done in your version.