C#大量資料匯出到Excel
阿新 • • 發佈：2021-07-05
private Excel.Application m_xlApp = new Excel.Application();
/// <summary>
/// 將DataTable資料匯出到Excel表
/// </summary>
/// <param name="dtTmp">要匯出的DataTable</param>
/// <param name="filePath">Excel的儲存路徑及名稱</param>
public void DataTabletoExcel(System.Data.DataTable dtTmp, string filePath){
if (dtTmp == null)
{
return;
}
long rowNum = dtTmp.Rows.Count;//行數
int columnNum = dtTmp.Columns.Count;//列數
m_xlApp = new Excel.Application();
m_xlApp.DisplayAlerts = false;//不顯示更改提示
m_xlApp.Visible = false;
Excel.Workbooks workbooks = m_xlApp.Workbooks;
Excel.Workbook workbook = workbooks.Add(Excel.XlWBATemplate.xlWBATWorksheet);Excel.Worksheet worksheet = (Excel.Worksheet)workbook.Worksheets[1];//取得Sheet1
try
{
//單張Excel表格最大行數
if (rowNum > 65536)
{
long pageRows = 65535; //定義每頁顯示的行數,行數必須小於65536
int scount = (int)(rowNum / pageRows); //匯出資料生成的表單數
if (scount * pageRows < rowNum) //當總行數不被pageRows整除時，經過四捨五入可能頁數不準
{
scount = scount + 1;}
for (int sc = 1; sc <= scount; sc++)
{
if (sc > 3) //這裡由1改為3，20140922
{
object missing = System.Reflection.Missing.Value;
worksheet = (Excel.Worksheet)workbook.Worksheets.Add(
missing, missing, missing, missing); //新增一個sheet
}
else
{
worksheet = (Excel.Worksheet)workbook.Worksheets[sc]; //取得sheet1
}
string[,] datas = new string[pageRows + 1, columnNum];
for (int i = 0; i < columnNum; i++) //寫入欄位
{
datas[0, i] = dtTmp.Columns[i].Caption; //表頭資訊
}
Excel.Range range = worksheet.get_Range(worksheet.Cells[1, 1], worksheet.Cells[1, columnNum]);
range.Interior.ColorIndex = 15; //15代表灰色
range.Font.Bold = true;
range.Font.Size = 9;
int init = int.Parse(((sc - 1) * pageRows).ToString());
int r = 0;
int index = 0;
int result;
if (pageRows * sc >= rowNum)
{
result = (int)rowNum;
}
else
{
result = int.Parse((pageRows * sc).ToString());
}
for (r = init; r < result; r++)
{
index = index + 1;
for (int i = 0; i < columnNum; i++)
{
object obj = dtTmp.Rows[r][dtTmp.Columns[i].ToString()];
datas[index, i] = obj == null ? "" : obj.ToString().Trim();
}
}
Excel.Range fchR = worksheet.get_Range(worksheet.Cells[1, 1], worksheet.Cells[index + 1, columnNum]);
fchR.Value2 = datas;
worksheet.Columns.EntireColumn.AutoFit(); //列寬自適應。
m_xlApp.WindowState = Excel.XlWindowState.xlMaximized; //Sheet表最大化
range = worksheet.get_Range(worksheet.Cells[1, 1], worksheet.Cells[index + 1, columnNum]);
range.Font.Size = 9;
range.RowHeight = 14.25;
range.Borders.LineStyle = 1;
range.HorizontalAlignment = 1;
}
}
else
{
string[,] datas = new string[rowNum + 1, columnNum];
for (int i = 0; i < columnNum; i++) //寫入欄位
{
datas[0, i] = dtTmp.Columns[i].Caption;
}
Excel.Range range = worksheet.get_Range(worksheet.Cells[1, 1], worksheet.Cells[1, columnNum]);
range.Interior.ColorIndex = 15; //15代表灰色
range.Font.Bold = true;
range.Font.Size = 9;
int r = 0;
for (r = 0; r < rowNum; r++)
{
for (int i = 0; i < columnNum; i++)
{
object obj = dtTmp.Rows[r][dtTmp.Columns[i].ToString()];
datas[r + 1, i] = obj == null ? "" : obj.ToString().Trim();
}
}
Excel.Range fchR = worksheet.get_Range(worksheet.Cells[1, 1], worksheet.Cells[rowNum + 1, columnNum]);
fchR.Value2 = datas;
worksheet.Columns.EntireColumn.AutoFit();//列寬自適應。
m_xlApp.WindowState = Excel.XlWindowState.xlMaximized;
range = worksheet.get_Range(worksheet.Cells[1, 1], worksheet.Cells[rowNum + 1, columnNum]);
range.Font.Size = 9;
range.RowHeight = 14.25;
range.Borders.LineStyle = 1;
range.HorizontalAlignment = 1;
}
workbook.Saved = true;
workbook.SaveCopyAs(filePath);
lblMsg.Text = "匯出成功！" + DateTime.Now.ToString();
}
catch (Exception ex)
{
string dd = Server.MapPath("~/Tmp/1.txt");
System.IO.File.AppendAllText(dd, "匯出異常：" + ex.Message + Environment.NewLine);
}
finally
{
EndReport();
}
}
/// <summary>
/// 退出報表時關閉Excel和清理垃圾Excel程序
/// </summary>
private void EndReport()
{
object missing = System.Reflection.Missing.Value;
try
{
m_xlApp.Workbooks.Close();
m_xlApp.Workbooks.Application.Quit();
m_xlApp.Application.Quit();
m_xlApp.Quit();
}
catch
{
}
finally
{
try
{
System.Runtime.InteropServices.Marshal.ReleaseComObject(m_xlApp.Workbooks);
System.Runtime.InteropServices.Marshal.ReleaseComObject(m_xlApp.Application);
System.Runtime.InteropServices.Marshal.ReleaseComObject(m_xlApp);
m_xlApp = null;
}
catch
{
}
try
{
//清理垃圾程序
this.killProcessThread();
}
catch
{
}
GC.Collect();
}
}
/// <summary>
/// 殺掉不死程序
/// </summary>
private void killProcessThread()
{
ArrayList myProcess = new ArrayList();
for (int i = 0; i < myProcess.Count; i++)
{
try
{
System.Diagnostics.Process.GetProcessById(int.Parse((string)myProcess[i])).Kill();
}
catch
{
}
}
}
工作過程中經常會用到將資料匯出到Excel中，一般情況下需要匯出的資料都是幾百幾千條或者上萬條，這都沒有什麼問題，但有時候會遇到特殊的需求，
客戶要求把幾十萬條甚至上百萬條的資料匯出到Excel中，這就比較麻煩了。當資料量很大匯出到Excel表格的時候通常會遇到兩個問題：一個是記憶體溢位，
由於需要處理的資料量比較大，導致Excel佔用的記憶體過多從而導致資料還沒有匯出完就因為記憶體溢位而失敗；另一個是每張Excel表單最多隻能有65536行，
所以當DataTable或DataSet中資料多於65536行時會報錯，這時候需要考慮Excel分頁功能。
程式由原始的將資料一個表格一個表格地寫入到EXCEL中，改變成程式先將資料存入二維陣列中，然後再將陣列值賦予EXCEL應用程式物件的VALUE屬性，
這樣就使匯出的效率提高很多，經測試匯出100萬資料沒問題。