接上文NPOI大数据分批写入同个Excel，这次是利用task多任务同时写入到多个Excel。
Form2.cs
private void btnExport_Click(object sender, EventArgs e)
{
try
{
txtSql.SafeCall(() =>
{
txtSql.AppendText("开始处理...\r\n");
}); string sqlCount = Sql.GetRecordSql(GetBusinessType(), "");
recordCount = db.ExecuteScalar(sqlCount);
rowIndex = 0; string[] sqlWhereArray = Sql.SqlWhereArray;
TaskFactory taskFactory = new TaskFactory();
Task[] tasks = new Task[sqlWhereArray.Length];
for (int k = 0; k < sqlWhereArray.Length; k++)
{
string sqlWhere = sqlWhereArray[k];
int sqlIndex = k; tasks[sqlIndex] = new Task(Export, sqlIndex);
tasks[sqlIndex].Start();
}
taskFactory.ContinueWhenAll(tasks, TaskEnded, TaskContinuationOptions.None); }
catch (Exception ex)
{
MessageBox.Show("发生异常，错误提示：" + ex.Message);
}
} private void Export(object state)
{
BusinessType businessType = GetBusinessType();
string[] DateRemarkArray = Sql.DateRemarkArray;
string sql = "";
string sqlWhere = "";
int sqlIndex = (int)state;
DataTable dt = null;
lock (moniter)
{
sqlIndex = (int)state;
sqlWhere = Sql.SqlWhereArray[sqlIndex];
sql = Sql.GetDataSql(businessType, sqlWhere);
dt = db.GetDataSet(sql).Tables[0];
} IWorkbook workbook = new XSSFWorkbook();
ISheet sheet = workbook.CreateSheet();
txtSql.SafeCall(() =>
{
txtSql.AppendText("条件" + (sqlIndex + 1).ToString() + "：" + DateRemarkArray[sqlIndex] + "\r\n");
}); IRow row0 = sheet.CreateRow(0);
for (int m = 0; m < dt.Columns.Count; m++)
{
DataColumn dc = dt.Columns[m];
row0.CreateCell(m).SetCellValue(dc.ColumnName);
} for (int i = 0; i < dt.Rows.Count; i++)
{
System.Threading.Interlocked.Increment(ref rowIndex); DataRow dr = dt.Rows[i];
IRow row = sheet.CreateRow(i+1);
for (int j = 0; j < dt.Columns.Count; j++)
{
row.CreateCell(j).SetCellValue(dr[j].ToString());
} Label lbl = GetLabel(sqlIndex + 1);
lbl.SafeCall(() =>
{
if (i == (dt.Rows.Count - 1))
{
txtSql.AppendText("条件" + (sqlIndex + 1).ToString() + "完成，行数：" + (i + 1).ToString() + "\r\n");
lbl.Text = "条件" + (sqlIndex + 1).ToString() + "完成";
}
else
{
lbl.Text = string.Format("正在导出第{0}个条件，第{1}行", (sqlIndex + 1).ToString(), (i + 1).ToString());
}
double x = rowIndex * 1.0 / recordCount * 100;
lblProgress.Text = string.Format("总行数：{0}, 当前完成总{1}行，百分占比：{2} %", recordCount.ToString(), rowIndex.ToString(), x.ToString("#0.0"));
});
}
string fileName = string.Format("{0}_{1}.xlsx", businessType.ToString(), DateRemarkArray[sqlIndex]);
FileStream outFs = new FileStream(fileName, FileMode.Create);
workbook.Write(outFs);
outFs.Close();
}