Excel表单打开并迭代写入

Question

我在c＃中的应用程序有写入excel表单的概率。 我的应用程序为其目的创建Excel表，并不写入它。 下面的代码仅提供参考..

class a 
{ 
    void m() 
    { 
     b bee=new b();  
     Excel.Application oXL; 
     Excel._Workbook oWB; 
     b.write(oXL,oWB); //will be called multiple times 
    } 
} 

class b 
{ 
    static b() //declared static so that only once excel workbook with sheets will be  created 
    { 
     Excel._Application oXL = new Excel.Application(); 
     Excel._Workbook oWB = (Excel._Workbook)(oXL.Workbooks.Add(Type.Missing)); 
    } 

    write(Excel.Application oXL, Excel._Workbook oWB) 
    { 
     oXL.Visible = true; //Here its throwing, Object reference not set to an instance of an 
        //Object 
    } 
} 

帮助将不胜感激，谢谢提前！

Answer 1

我想你想沿着以下行有代码：

class a 
{ 
    b bee; 
    public a() 
    { 
     bee = new b(); 
    } 

    void m() 
    { 
     b.write(oXL,oWB); //will be called multiple times 
    } 
} 

class b 
{ 
    public b() 
    { 
     Excel._Application oXL = new Excel.Application(); 
     Excel._Workbook oWB = (Excel._Workbook)(oXL.Workbooks.Add(Type.Missing)); 
    } 

    write() 
    { 
     oXL.Visible = true; 
    } 
} 

然后，您需要做当然，您只需创建a的许多实例就像您想要的Excel工作表一样。

您可以使用它像这样：

a aa = new a(); 
for(...) 
    aa.m(); 

Answer 2

void m() 
{ 
    b bee=new b();  
    Excel.Application oXL; // not initialized here! 
    Excel._Workbook oWB; // not initialized here! 
    b.write(oXL,oWB);  // calling with uninitialized values! 
} 

// ...

class b 
{ 
    static b() 
    { 

     // here you declare two local variables not visible outside of your 
     // static constructor. 
     Excel._Application oXL = new Excel.Application(); 
     Excel._Workbook oWB = (Excel._Workbook)(oXL.Workbooks.Add(Type.Missing)); 
    } 

    // oXL here is a parameter, meaning it is completely different from 
    // the local oXL in your static constructor 
    void write(Excel.Application oXL, Excel._Workbook oWB) 
    { 
     oXL.Visible = true; 
    } 
} 

我想你想要的是申报OXL和OWB为B类的成员变量。尝试是这样的：

void m() 
{ 
    b bee=new b();  
    b.write(); 
} 

// ...

public class b 
{ 
    Excel._Application oXL; 
    Excel._Workbook oWB; 

    public b() 
    { 

     oXL = new Excel.Application(); 
     oWB = (Excel._Workbook)(oXL.Workbooks.Add(Type.Missing)); 
    } 

    public void write() 
    { 
     // do something with cXL and oWB here 
    } 
}