大家看下 数据导出excel出现问题
using Excel;
using System.Data;

private DataSet ds = new DataSet();
private DataView dv;
private LinkDataBase link = new LinkDataBase();
private string sendTableName = "aa ";
private string sendStrSQL = "select distinct 销售单号,名称,销售日期,金额 from aa order by 销售日期 ";
private System.Windows.Forms.DataGrid dgrd_StorageSearch;


public shoukuan()
{
//
// Windows 窗体设计器支持所必需的
//
InitializeComponent();
this.selectDataBase();

//
// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
//

private void selectDataBase()
{
this.ds = this.link.SelectDataBase(sendStrSQL,sendTableName);
this.dv = new DataView(ds.Tables[0]);
this.dgrd_StorageSearch.DataSource = dv;
}


查询按钮
private void btn_Search_Click(object sender, System.EventArgs e)
{
string strRowFilter = " ";
string str1= "销售单号 like ' " + txt1.Text.Trim() + "% ' ";
string str2= "名称 like ' " + txt2.Text.Trim() + "% ' ";
string strWareNumFilter = "销售日期 > = ' " + txt_WareNum.Text.Trim()+ "% ' ";
string strWareWordFilter = "销售日期 <= ' " + txt_WareWord.Text.Trim() + "% ' ";

if (txt1.Text.Trim() != " ")
strRowFilter += str1 + " and ";
if (txt2.Text.Trim() != " ")
strRowFilter += str2 + " and ";
if (txt_WareNum.Text.Trim() != " ")
strRowFilter += strWareNumFilter + " and ";
if (txt_WareWord.Text.Trim() != " ")
strRowFilter += strWareWordFilter + " and ";
if (strRowFilter != " ") // 存在查询条件
strRowFilter = strRowFilter.Substring(0,strRowFilter.Length-5);
dv.RowFilter = strRowFilter;
this.txt1.Text = " ";
this.txt2.Text = " ";
this.txt_WareWord.Text = " ";
this.txt_WareNum.Text = " ";
}

导出excel按钮
private void button1_Click(object sender, System.EventArgs e)
{
System.Data.DataSet ds = (System.Data.DataSet) this.dgrd_StorageSearch.DataSource;

if(ds==null|| ds.Tables.Count <=0)
{
MessageBox.Show( "您没查询或导入数据表，不能导出Excel！！！\n 请进行查询或导入数据表！！ ");
return;
}
Excel.Application ExcelObj = null;
ExcelObj = new Excel.Application();
ExcelObj.Visible =false;
SaveFileDialog sf = new SaveFileDialog();

进销存管理系统.util.GridUtil gridutil=new 进销存管理系统.util.GridUtil();
gridutil.GridXls(sf,this.dgrd_StorageSearch,ExcelObj);
ExcelObj.Quit();
}


现在出现的问题是：
查询功能是可以的，但我导出是
出现（这条语句在导出按钮中）
System.Data.DataSet ds = (System.Data.DataSet)this.dgrd_StorageSearch.DataSource;提示错误

未处理的“System.InvalidCastException”类型的异常出现在 进销存管理系统.exe 中。
其他信息: 指定的转换无效。



[解决办法]
无法将this.dgrd_StorageSearch.DataSource转换为DataSet,断点看一下是否为空引用或类型不匹配
[解决办法]
public bool ExportExcel(DataTable table,string strExcelFileName)
{

try
{
//object objOpt = Missing.Value;
Excel.Application excel = new Excel.Application();
excel.Visible = true;
Excel._Workbook wkb = excel.Workbooks.Add(true);
Excel._Worksheet wks = (Excel._Worksheet)wkb.ActiveSheet;

wks.Visible = Excel.XlSheetVisibility.xlSheetVisible;

int rowIndex=1;
int colIndex=0;
foreach(DataColumn col in table.Columns)
{
colIndex++;
excel.Cells[1,colIndex]=col.ColumnName;
}

foreach(DataRow row in table.Rows)
{
rowIndex++;
colIndex=0;
foreach(DataColumn col in table.Columns)
{
colIndex++;
excel.Cells[rowIndex,colIndex]=row[col.ColumnName].ToString();
}
}

wkb.SaveAs(strExcelFileName,true,null,null,false,false,Excel.XlSaveAsAccessMode.xlNoChange,null,null,null,null,null);

return true;
}
catch
{
return false;
}
}
[解决办法]
上面不是有例子了吗？
楼主怎么不试试？
你先看看代码嘛，稍微改改就可以了的，你要首先了解原理
[解决办法]
即是一行一行的转换数据了
[解决办法]
带格式的导出
public void OpenExcelFile()
{
try
{
Excel.Application excelapp;
excelapp = new Microsoft.Office.Interop.Excel.Application();
Excel.Workbook book = excelapp.Workbooks.Open(Application.StartupPath + @ "\ReportFile\018.xlt ",
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);

Excel.Worksheet st1 = (Excel.Worksheet)book.Worksheets[1];

int rowBase = 3;
int colBase = 1;
int rowIndex = rowBase;
int colIndex = colBase;

foreach (DataRowView row in this.m_DataView)
{
if (!(bool)row[ "Selected "])
{
continue;
}

if(row[ "YunDanState "].ToString()!= "可取货 ")
{
continue;
}

Excel.Range range = (Excel.Range)st1.Rows[rowIndex + 1, Missing.Value];
range.Insert(Excel.XlInsertShiftDirection.xlShiftDown, Missing.Value);

st1.Cells[rowIndex, colIndex] = " ";
colIndex++;

st1.Cells[rowIndex, colIndex] = " ' " + row[ "YeWuLeiXings "].ToString();
colIndex++;

st1.Cells[rowIndex, colIndex] = " ' " + row[ "BeiZhu "].ToString();

rowIndex++;
colIndex = colBase;
}

excelapp.Visible = true;
}
catch (Exception ex)
{
Wip.Common.ShowExecResult(Wip.Common.GetExecResult(ex), false);
}
finally
{
Cursor.Current = Cursors.Default;
}
}