啊，求助，EXCEL导入datagridview, 日期显示的是一串字母。。。怎么回事啊？代码见内。
导入Excel
private void button1_Click(object sender, EventArgs e)
{
OpenFileDialog ofd = new OpenFileDialog();
ofd.Filter = "Excel文件(*.xls)|*.xls";
if (ofd.ShowDialog() == DialogResult.OK)
{
string filename = ofd.FileName;
ExcelToDataGridView(filename);
}
}

private void ExcelToDataGridView(string filename)
{
Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();
Microsoft.Office.Interop.Excel.Workbook workbook;
Microsoft.Office.Interop.Excel.Worksheet worksheet;

object oMissing = System.Reflection.Missing.Value;

workbook = excel.Workbooks.Open(filename, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing);

worksheet = (Worksheet)workbook.Worksheets[1];

int rowCount = worksheet.UsedRange.Rows.Count;
int colCount = worksheet.UsedRange.Columns.Count;


Microsoft.Office.Interop.Excel.Range range1;

System.Data.DataTable dt = new System.Data.DataTable();

for (int i = 0; i <= colCount; i++)
{
try
{
range1 = worksheet.get_Range((object)worksheet.Cells[1, i + 1], (object)worksheet.Cells[1, i + 1]);
dt.Columns.Add(range1.Value2.ToString());

}
catch (Exception)

{

}
}
for (int j = 1; j < rowCount; j++)
{
DataRow dr = dt.NewRow();
for (int i = 0; i <= colCount; i++)
{
try
{
range1 = worksheet.get_Range((object)worksheet.Cells[j + 1, i + 1], (object)worksheet.Cells[j + 1, i + 1]);
dr[i] = range1.Value2.ToString();
}
catch (Exception)
{ }
}

dt.Rows.Add(dr);
}
dataGridView1.DataSource = dt;
//for (int i = 0; i < dataGridView1.Rows.Count; i++)
//{
// dataGridView1.Rows[i].Cells[5].Value = DateTime.Parse(dataGridView1.Rows[i].Cells[5].Value.ToString()).ToString("yyyy年m月d日");
//}
excel.Quit();
}

[解决办法]
//建议用这种方式读取EXCEL (excel版本为2007)
public System.Data.DataTable Open(string filePath, string sheetName)
{

if (!sheetName.Contains("$"))
{
sheetName = sheetName + "$";
}

OleDbConnection connection = null;
try
{
DataSet ds = new DataSet();
string strExcelNew = "";
strExcelNew = string.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=\"Excel 12.0;HDR=YES;IMEX=1\"", filePath);

connection = new OleDbConnection(strExcelNew);
connection.Open();
OleDbDataAdapter adapter = new OleDbDataAdapter("select * from [" + sheetName + "]", connection);
adapter.SelectCommand.CommandTimeout = 0;
adapter.Fill(ds, sheetName);
return ds.Tables[0];
}
catch (Exception ex) {
}

//调用
private void button3_Click(object sender, EventArgs e)
{
string filepath="文件路径名";
string sheetname="文件Sheet页名";
dataGridView1.DataSource = Open(filepath，sheetname)
}

接分了！！！！
[解决办法]
读取存储时将日期格式化