DataGridView 导出 Excel

用来记录一下。老是忘记，这个是比较稳定的方法：）

private void SaveExcel(DataGridView dataGridView1,string filename)
{
    if (dataGridView1.Rows.Count == 0)   
        return;   

    Microsoft.Office.Interop.Excel.ApplicationClass _x = 
　　　　　　new Microsoft.Office.Interop.Excel.ApplicationClass();
    _x.UserControl = false;
    Microsoft.Office.Interop.Excel.WorkbookClass wb = 
　　　　　　(Microsoft.Office.Interop.Excel.WorkbookClass)this._x.Workbooks.Add(System.Reflection.Missing.Value);
    //生成表头
    for (int i = 0; i < dataGridView1.ColumnCount; i++)
    {
        _x.Cells[1, i + 1] = dataGridView1.Columns[i].HeaderText;
    }

    //填充数据    
    for (int i = 0; i < dataGridView1.RowCount - 1; i++)
    {
        for (int j = 0; j < dataGridView1.ColumnCount; j++)
        {
            if (dataGridView1[j, i].ValueType == typeof(string))
            {
                _x.Cells[i + 2, j + 1] = "'" + dataGridView1[j, i].Value.ToString();
            }
            else
            {
                _x.Cells[i + 2, j + 1] = dataGridView1[j, i].Value.ToString();
            }
        }
    }

    wb.Saved = true;
    this._x.ActiveWorkbook.SaveCopyAs(filename);
    this._x.Quit();
    System.Runtime.InteropServices.Marshal.ReleaseComObject((object)_x);
    System.GC.Collect();
}