如何检查Excel是否打开，如果是，保存并关闭它C#

Question

我想检查 excel 是否打开。如果是，我想保存活动工作簿并关闭 Excel。本质上，我的目标是杀死每个 excel 进程，但在此之前我想保存 excel 工作簿。这是我的代码...

Process[] localByName = Process.GetProcessesByName("excel");
        for (int i = 0; i < localByName.Length; i++)
        {
            Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();
            Workbook wb = xlApp.ActiveWorkbook; 
            wb.Save();  // I get an error here. "Object reference not set to an instance of an object".
            GC.Collect();
            GC.WaitForPendingFinalizers();
            wb.Close(); 
            Marshal.FinalReleaseComObject(wb);  
            xlApp.Quit();    
            Marshal.FinalReleaseComObject(xlApp);    
        }

我读到 xlApp.ActiveWorkbook 以只读模式获取工作簿。这可能是我的问题吗？如果是这样，请提出一个成功的方法来解决这个问题。谢谢！

Answer 1

> Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application(); 这会创建 Excel.Application COM 对象的新实例，但不会返回一个活动实例。为此，请尝试

Excel.Application xlApp = null;
while(xlApp == null)
{
    try
    {
        xlApp = (Excel.Application)System.Runtime.InteropServices.Marshal.GetActiveObject("Excel.Application");
    }
    catch (System.Runtime.InteropServices.COMException ex)
    {
        // no more instances/error, exit out of loop
        break;
    }

    // do whatever with the instance
    Workbook wb = xlApp.ActiveWorkbook; 
    wb.Save();
    GC.Collect();
    GC.WaitForPendingFinalizers();
    wb.Close(); 
    Marshal.FinalReleaseComObject(wb);  
    xlApp.Quit();    
    Marshal.FinalReleaseComObject(xlApp);

    // set null to continue loop
    xlApp = null;
}

来源：Get instance of Excel application with C# by Handle