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ASP.NET教程:Excel在.Net下驻留内存的解决方法

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ASP.NET教程:Excel在.Net下驻留内存的解决方法
ASP.NET教程:Excel在.Net下驻留内存的解决方法ASP.NET
【网络综合-ASP.NET教程:Excel在.Net下驻留内存的解决方法】:

这段时间在VS 2003的WebForm 方式下对Excel 进行操作,遇到一个最为头疼的问题就是对Excel操作完毕后Excel不能够正常关闭,系统退出后,Excel总是驻留在内存中。但是这段代码放到WinForm的程序中又没有问题。在网上进行了查找也没有找到有效可行的办法。经过无数次的尝试,终于解决如下:

原来书写如下:

private Excel.Application m_app;

private Excel.Workbook m_workbook;

this.m_app = new Excel.ApplicationClass();

this.m_app.DisplayAlerts = false;

this.m_workbook = this.m_app.Workbooks.Open(sFilePath, Missing.Value,

Missing.Value, Missing.Value, Missing.Value,

Missing.Value, Missing.Value, Missing.Value,

Missing.Value, Missing.Value, Missing.Value,

Missing.Value, Missing.Value, Missing.Value,

Missing.Value );

修改后如下:

private Excel.Application m_app;

private Excel.Workbooks m_workbooks;

private Excel.Workbook m_workbook;

this.m_app = new Excel.ApplicationClass();

this.m_app.DisplayAlerts = false;

m_workbooks = this.m_app.Workbooks;

this.m_workbook = this.m_workbooks.Open(sFilePath, Missing.Value,

Missing.Value, Missing.Value, Missing.Value,

Missing.Value, Missing.Value, Missing.Value,

Missing.Value, Missing.Value, Missing.Value,

Missing.Value, Missing.Value, Missing.Value,

Missing.Value );

同样对Sheet的操作如下:

修改前如下:

Excel._Worksheet worksheet1 = null;

worksheet1 = (Excel._Worksheet) this.m_workbook.Worksheets.get_Item(sSheetName);

修改后如下:

Excel.Sheets sheets = null ;

Excel._Worksheet worksheet1 = null;

sheets = this.m_workbook.Worksheets;

worksheet1 = (Excel._Worksheet) sheets.get_Item(sSheetName);

发现区别了吗?原来Workbooks,Worksheets这两个类没有被实例化就直接使用了,造成该类不能够被回收。最终造成Excel在内存的驻留。

最终以如下方式释放。

private void ReleaseAllRef(Object obj)

{

try

{

if (obj != null )

{

while (Marshal.ReleaseComObject(obj) > 1);

}

}

finally

{

obj = null;

}

}

private void Release()

{

if (m_app != null )

{

m_app.Quit() ;

}

ReleaseAllRef(m_workbook) ;

m_workbook = null ;

ReleaseAllRef(m_workbooks) ;

m_workbooks = null ;

ReleaseAllRef(m_app) ;

m_app = null ;

System.GC.Collect() ;

}

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