C# 导入excel数据，解决关闭excel后不能释放资源的问题
最近项目上有导入excel的需求，其实导入一个固定格式的excel数据非常容易，但是，发现一个问题就是，导入excel后，用户在打开excel时，必须要打开2次才能打开excel，这让用户很不爽；开始查找原因：excel的进程关闭不了，资源不能释放，于是就想尽办法释放com对象excel实例，在博客园就找到一篇文章，所以就做个学习笔记了。
public class ExcelHelper
{
#region 成员变量
private string templetFile = null;
private string outputFile = null;
private object missing = Missing.Value;
private DateTime beforeTime; //Excel启动之前时间
private DateTime afterTime; //Excel启动之后时间
Microsoft.Office.Interop.Excel.Application app;
Microsoft.Office.Interop.Excel.Workbook workBook;
Microsoft.Office.Interop.Excel.Worksheet workSheet;
Microsoft.Office.Interop.Excel.Range range;
Microsoft.Office.Interop.Excel.Range range1;
Microsoft.Office.Interop.Excel.Range range2;
Microsoft.Office.Interop.Excel.TextBox textBox;
private int sheetCount = 1; //WorkSheet数量
private string sheetPrefixName = "页";
#endregion
#region 公共属性
/// <summary>
/// WorkSheet前缀名，比如：前缀名为“页”，那么WorkSheet名称依次为“页-1，页-2...”
/// </summary>
public string SheetPrefixName
{
set { this.sheetPrefixName = value; }
}
/// <summary>
/// WorkSheet数量
/// </summary>
public int WorkSheetCount
{
get { return workBook.Sheets.Count; }
}
/// <summary>
/// Microsoft.Office.Interop.Excel模板文件路径
/// </summary>
public string TempletFilePath
{
set { this.templetFile = value; }
}
/// <summary>
/// 输出Excel文件路径
/// </summary>
public string OutputFilePath
{
set { this.outputFile = value; }
}
#endregion
public static void MakeExcelDocs(string sourcepath, string destinpath, string newname)
{
destinpath = destinpath + "\\" + newname + ".xls";
// Ensure that the target does not exist.
File.Delete(destinpath);
// Copy the file.
File.Copy(sourcepath, destinpath);
// Try to copy the same file again, which should succeed.
File.Copy(sourcepath, destinpath, true);
}
public static void OpenExcelDocs(string filename,string[] content)
{
Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application(); //引用Excel对象
Microsoft.Office.Interop.Excel.Workbook book = excel.Workbooks.Open(filename,Type.Missing,Type.Missing,Type.Missing,Type.Missing,Type.Missing
,Type.Missing,Type.Missing,Type.Missing,Type.Missing,Type.Missing,Type.Missing,Type.Missing,Type.Missing,Type.Missing); //引用Excel工作簿
Microsoft.Office.Interop.Excel.Worksheet sheet = (Microsoft.Office.Interop.Excel.Worksheet)book.Sheets.get_Item(1); ; //引用Excel工作页面
excel.Visible = false;
string[] newcontent = StringHelper.Modify(content);
sheet.Cells[10, 3] = newcontent[0];
sheet.Cells[11, 3] = newcontent[1];
sheet.Cells[12, 3] = newcontent[2];
sheet.Cells[13, 3] = newcontent[3];
sheet.Cells[14, 3] = newcontent[4];
sheet.Cells[15, 3] = newcontent[5];
sheet.Cells[16, 3] = newcontent[6];
sheet.Cells[17, 3] = newcontent[7];
book.Save();
book.Close(Type.Missing, Type.Missing, Type.Missing);
excel.Quit();
IntPtr t = new IntPtr(excel.Hwnd);
int k = 0;
GetWindowThreadProcessId(t, out k);
System.Diagnostics.Process p = System.Diagnostics.Process.GetProcessById(k);
p.Kill();
//sheet = null;
//book = null;
//excel = null
//System.Runtime.InteropServices.Marshal.ReleaseComObject(sheet);
//System.Runtime.InteropServices.Marshal.ReleaseComObject(book);
//System.Runtime.InteropServices.Marshal.ReleaseComObject(excel);
}
[DllImport("User32.dll", CharSet = CharSet.Auto)]
public static extern int GetWindowThreadProcessId(IntPtr hwnd, out int ID);
public static void OpenExcelDocs2(string filename, double[] content)
{
Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application(); //引用Excel对象
Microsoft.Office.Interop.Excel.Workbook book = excel.Workbooks.Open(filename, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing
, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing); //引用Excel工作簿
Microsoft.Office.Interop.Excel.Worksheet sheet = (Microsoft.Office.Interop.Excel.Worksheet)book.Sheets.get_Item(1); ; //引用Excel工作页面
excel.Visible = false;
sheet.Cells[24, 3] = content[1];
sheet.Cells[25, 3] = content[0];
book.Save();
book.Close(Type.Missing, Type.Missing, Type.Missing);
excel.Quit(); //应用程序推出，但是进程还在运行
IntPtr t = new IntPtr(excel.Hwnd); //杀死进程的好方法，很有效
int k = 0;
GetWindowThreadProcessId(t, out k);
System.Diagnostics.Process p = System.Diagnostics.Process.GetProcessById(k);
p.Kill();
//sheet = null;
//book = null;
//excel = null; //不能杀死进程
//System.Runtime.InteropServices.Marshal.ReleaseComObject(sheet); //可以释放对象，但是不能杀死进程
//System.Runtime.InteropServices.Marshal.ReleaseComObject(book);
//System.Runtime.InteropServices.Marshal.ReleaseComObject(excel);
}
}
原文引自：http://www.cnblogs.com/zhangjun1130/archive/2010/12/06/1897717.html
下面是我自己用到的代码，记下来以备后用。
Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application(); //引用Excel对象
Microsoft.Office.Interop.Excel.Workbook book = excel.Workbooks.Open(textBox1.Text.Trim(), Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing
, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing); //引用Excel工作簿
Microsoft.Office.Interop.Excel.Worksheet sheet = (Microsoft.Office.Interop.Excel.Worksheet)book.Sheets.get_Item(1); ; //引用Excel工作页面
excel.Visible = false;
//读取excel内容代码部分
book.Save();
book.Close(Type.Missing, Type.Missing, Type.Missing);
excel.Quit();
IntPtr t = new IntPtr(excel.Hwnd);
int k = 0;
GetWindowThreadProcessId(t, out k);
System.Diagnostics.Process p = System.Diagnostics.Process.GetProcessById(k);
p.Kill();
而且 在上述代码的方法上面，需要导入win32组件，代码如下：
[DllImport("User32.dll", CharSet = CharSet.Auto)]
public static extern int GetWindowThreadProcessId(IntPtr hwnd, out int ID);