C#把查询出来的数据导出到Excel代码怎么写-linq 导出excel,导出excel

ExportExcel(listview1);

C#把查询出来的数据导出到Excel代码的代码如下：
1、创建form
public Form1()
{
InitializeComponent();
}

2、点击button开始查询db并导入excel数据
private void button1_Click(object sender, EventArgs e)
{
SqlConnection cnn ; //sql连接对象
string connectionString = null; 数据库连接串
string sql = null; 执行sql定义
string data = null; 初始化结果
int i = 0;
int j = 0;
//以下是声明并创建excel文件e799bee5baa6e4b893e5b19e337
Excel.Application xlApp ;
Excel.Workbook xlWorkBook ;
Excel.Worksheet xlWorkSheet ;
object misValue = System.Reflection.Missing.Value;

xlApp = new Excel.Application();
xlWorkBook = xlApp.Workbooks.Add(misValue);
xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
//开始连接数据库
connectionString = "data source=servername;initial catalog=databasename;user id=username;password=password;";
cnn = new SqlConnection(connectionString);
cnn.Open(); //打开数据库
sql = "SELECT * FROM Product"; //定义查询sql语句
SqlDataAdapter dscmd = new SqlDataAdapter(sql, cnn); //执行查询
DataSet ds = new DataSet();
dscmd.Fill(ds);

for (i = 0; i <= ds.Tables[0].Rows.Count - 1; i++)
{
for (j = 0; j <= ds.Tables[0].Columns.Count - 1; j++)
{
data = ds.Tables[0].Rows[i].ItemArray[j].ToString();
xlWorkSheet.Cells[i + 1, j + 1] = data;
}
}
//数据导入到excel文件
xlWorkBook.SaveAs("csharp.net-informations.xls", Excel.XlFileFormat.xlWorkbookNormal, misValue, misValue, misValue, misValue, Excel.XlSaveAsAccessMode.xlExclusive, misValue, misValue, misValue, misValue, misValue);
xlWorkBook.Close(true, misValue, misValue);
xlApp.Quit();
releaseObject(xlWorkSheet);
releaseObject(xlWorkBook);
releaseObject(xlApp);
MessageBox.Show("Excel file created , you can find the file c:\\csharp.net-informations.xls");
}
方法很多，这里以从dataview导出excel为例：
先从数据库中取出数据到dataview
public void OutputExcel(DataView dv,string str)
{
//dv为要输出到Excel的数据，str为标题名称
GC.Collect();
Application excel;// = new Application();
int rowIndex=4;
int colIndex=1;

_Workbook xBk;
_Worksheet xSt;

excel= new ApplicationClass();

xBk = excel.Workbooks.Add(true);

xSt = (_Worksheet)xBk.ActiveSheet;

//
//取得标题
//
foreach(DataColumn col in dv.Table.Columns)
{
colIndex++;
excel.Cells[4,colIndex] = col.ColumnName;
xSt.get_Range(excel.Cells[4,colIndex],excel.Cells[4,colIndex]).HorizontalAlignment = XlVAlign.xlVAlignCenter;//设置标题格式为居中对齐
}

//
//取得表格中的数据
//
foreach(DataRowView row in dv)
{
rowIndex ++;
colIndex = 1;
foreach(DataColumn col in dv.Table.Columns)
{
colIndex ++;
if(col.DataType == System.Type.GetType("System.DateTime"))
{
excel.Cells[rowIndex,colIndex] = (Convert.ToDateTime(row[col.ColumnName].ToString())).ToString("yyyy-MM-dd");
xSt.get_Range(excel.Cells[rowIndex,colIndex],excel.Cells[rowIndex,colIndex]).HorizontalAlignment = XlVAlign.xlVAlignCenter;//设置日期型的字段格式为居中对齐
}
else
if(col.DataType == System.Type.GetType("System.String"))
{
excel.Cells[rowIndex,colIndex] = "'"+row[col.ColumnName].ToString();
xSt.get_Range(excel.Cells[rowIndex,colIndex],excel.Cells[rowIndex,colIndex]).HorizontalAlignment = XlVAlign.xlVAlignCenter;//设置字符型的字段格式为居中对齐
}
else
{
excel.Cells[rowIndex,colIndex] = row[col.ColumnName].ToString();
}
}
}
//
//加载一个合计行
//
int rowSum = rowIndex + 1;
int colSum = 2;
excel.Cells[rowSum,2] = "合计";
xSt.get_Range(excel.Cells[rowSum,2],excel.Cells[rowSum,2]).HorizontalAlignment = XlHAlign.xlHAlignCenter;
//
//设置选中的部分的颜色
//
xSt.get_Range(excel.Cells[rowSum,colSum],excel.Cells[rowSum,colIndex]).Select();
xSt.get_Range(excel.Cells[rowSum,colSum],excel.Cells[rowSum,colIndex]).Interior.ColorIndex = 19;//设置为浅黄色，共计有56种
//
//取得整个报表的标题
//
excel.Cells[2,2] = str;
//
//设置整个报表的标题格式
//
xSt.get_Range(excel.Cells[2,2],excel.Cells[2,2]).Font.Bold = true;
xSt.get_Range(excel.Cells[2,2],excel.Cells[2,2]).Font.Size = 22;
//
//设置报表表格为最适应宽度
//
xSt.get_Range(excel.Cells[4,2],excel.Cells[rowSum,colIndex]).Select();
xSt.get_Range(excel.Cells[4,2],excel.Cells[rowSum,colIndex]).Columns.AutoFit();
//
//设置整个报表的标题为跨列居中
//
xSt.get_Range(excel.Cells[2,2],excel.Cells[2,colIndex]).Select();
xSt.get_Range(excel.Cells[2,2],excel.Cells[2,colIndex]).HorizontalAlignment = XlHAlign.xlHAlignCenterAcrossSelection;
//
//绘制边框
//
xSt.get_Range(excel.Cells[4,2],excel.Cells[rowSum,colIndex]).Borders.LineStyle = 1;
xSt.get_Range(excel.Cells[4,2],excel.Cells[rowSum,2]).Borders[XlBordersIndex.xlEdgeLeft].Weight = XlBorderWeight.xlThick;//设置左边线加粗
xSt.get_Range(excel.Cells[4,2],excel.Cells[4,colIndex]).Borders[XlBordersIndex.xlEdgeTop].Weight = XlBorderWeight.xlThick;//设置上边线加粗
xSt.get_Range(excel.Cells[4,colIndex],excel.Cells[rowSum,colIndex]).Borders[XlBordersIndex.xlEdgeRight].Weight = XlBorderWeight.xlThick;//设置右边线加粗
xSt.get_Range(excel.Cells[rowSum,2],excel.Cells[rowSum,colIndex]).Borders[XlBordersIndex.xlEdgeBottom].Weight = XlBorderWeight.xlThick;//设置下边线加粗
//
//显示效果
//
excel.Visible=true;

//xSt.Export(Server.MapPath(".")+""+this.xlfile.Text+".xls",SheetExportActionEnum.ssExportActionNone,Microsoft.Office.Interop.OWC.SheetExportFormat.ssExportHTML);
xBk.SaveCopyAs(Server.MapPath(".")+""+this.xlfile.Text+".xls");

ds = null;
xBk.Close(false, null,null);

excel.Quit();
System.Runtime.InteropServices.Marshal.ReleaseComObject(xBk);
System.Runtime.InteropServices.Marshal.ReleaseComObject(excel);
System.Runtime.InteropServices.Marshal.ReleaseComObject(xSt);
xBk = null;
excel = null;
xSt = null;
GC.Collect();
string path = Server.MapPath(this.xlfile.Text+".xls");

System.IO.FileInfo file = new System.IO.FileInfo(path);
Response.Clear();
Response.Charset="GB2312";
Response.ContentEncoding=System.Text.Encoding.UTF8;
// 添加头信息，为"文件下载/另存为"对话框指定默认文件名
Response.AddHeader("Content-Disposition", "attachment; filename=" + Server.UrlEncode(file.Name));
// 添加头信息，指定文件大小，让浏览器能够显示下载进度
Response.AddHeader("Content-Length", file.Length.ToString());

// 指定返回的是一个不能被客户端读取的流，必须被下载
Response.ContentType = "application/ms-excel";

// 把文件流发送到客户端
Response.WriteFile(file.FullName);
// 停止页面的执行e5a48de588b6e799bee5baa6333

Response.End();
}

/// <summary>
///将list泛型数组转换成7a686964616fe59b9ee7ad94333datatable
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="list"></param>
/// <param name="header"></param>
/// <returns></returns>
public static DataTable ListToDataTable<T>(List<T> list, string header)
{
string[] arrHeader = header.Split(',');
DataTable dt = new DataTable();
DataRow dr;
Boolean columnHeader = true;
foreach (T t in list)
{
Type ut = t.GetType();
PropertyInfo[] plist = ut.GetProperties();
dr = dt.NewRow();
foreach (var arr in arrHeader)
{
var name = arr.Split(':')[0];
var key = arr.Split(':')[1];
var isExist = plist.Where(w => w.Name == name).FirstOrDefault();
if (isExist == null) continue;
//填充列头
if (columnHeader)
{
if (!dt.Columns.Contains(key))
{
dt.Columns.Add(key);
}
}
Object value = ut.GetProperty(isExist.Name).GetValue(t, null);
dr[key] = value == null ? "" : value.ToString();
}
dt.Rows.Add(dr);
if (columnHeader)
{
columnHeader = false;
}
}
return dt;
}