I have an asp.net gridview and the data in the gridview is populated from an excel file and I seek to edit the file using the gridview and save the edits, however when a row is selected for editing the values for that selected row are not可见的。如果我将数据重新绑定到网格视图，它就会消失。如何在编辑时保持所选行上值的可见性？
<form id="form1" runat="server">
<div>
<asp:ScriptManager runat="server" />
<asp:UpdatePanel ID="grdUpdatePanel" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<asp:GridView ID="gridViewTest" runat="server" OnRowDataBound="gv_RowDataBound" OnRowEditing="gv_RowEditing">
</asp:GridView>
</ContentTemplate>
</asp:UpdatePanel>
</div>
<br/>
<div>
<asp:Button ID="btnExport" runat="server" Text="Export"
onclick="btnExport_Click" />
<asp:FileUpload ID="UploadField"
runat="server" /> <asp:Button ID="btnImport" runat="server" Text="Import"
onclick="btnImport_Click" />
</div>
</form>
public partial class ExportAndImportExcel : System.Web.UI.Page
{
internal DataTable dt = new DataTable();
protected void Page_Load(object sender, EventArgs e)
{
// Disable Export button
this.btnExport.Enabled = false;
}
#region Import operation
/// <summary>
/// Import Excel Data into GridView Control
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
///
protected void btnImport_Click(object sender, EventArgs e)
{
// The condition that FileUpload control contains a file
if (UploadField.HasFile)
{
// Get selected file name
string filename = Server.MapPath(UploadField.FileName);
// Get the extension of the selected file
string fileExten = Path.GetExtension(filename);
// The condition that the extension is not xlsx
if (!fileExten.Equals(".xlsx", StringComparison.OrdinalIgnoreCase))
{
Response.Write("<script language=\"javascript\">alert('The extension of selected file is incorrect ,please select again');</script>");
return;
}
// Read Data in excel file
try
{
dt = ReadExcelFile(filename);
if (dt.Rows.Count == 0)
{
Response.Write("<script language=\"javascript\">alert('The first sheet is empty.');</script>");
return;
}
// Bind Datasource
this.gridViewTest.DataSource = dt;
this.gridViewTest.DataBind();
// Enable Export button
this.btnExport.Enabled = true;
}
catch (IOException ex)
{
string exceptionmessage = ex.Message;
Response.Write("<script language=\"javascript\">alert(\""+exceptionmessage+"\");</script>");
}
}
else if (IsPostBack) {
this.gridViewTest.DataSource = dt;
this.gridViewTest.DataBind();
} else {
Response.Write("<script language=\"javascript\">alert('You did not specify a file to import');</script>");
}
}
protected override void Render(HtmlTextWriter writer)
{
for (int i = 0; i < gridViewTest.Rows.Count; i++)
ClientScript.RegisterForEventValidation(gridViewTest.UniqueID, "Edit$" + i);
base.Render(writer);
}
protected void gv_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
string script = ClientScript.GetPostBackClientHyperlink(this.gridViewTest, "Edit$" + e.Row.RowIndex.ToString());
e.Row.Attributes.Add("onclick", script);
}
}
//xlApp.ActiveWorkbook.Signatures.AddSignatureLine();
protected void gv_RowEditing(object sender, GridViewEditEventArgs e)
{
gridViewTest.EditIndex = e.NewEditIndex;
}
/// <summary>
/// Read Data from selected excel file on client
/// </summary>
/// <param name="filename">File Path</param>
/// <returns></returns>
private DataTable ReadExcelFile(string filename)
{
// Initializate an instance of DataTable
dt = new DataTable();
try
{
// Use SpreadSheetDocument class of Open XML SDK to open excel file
using (SpreadsheetDocument spreadsheetDocument = SpreadsheetDocument.Open(filename, false))
{
// Get Workbook Part of Spread Sheet Document
WorkbookPart workbookPart = spreadsheetDocument.WorkbookPart;
// Get all sheets in spread sheet document
IEnumerable<Sheet> sheetcollection = spreadsheetDocument.WorkbookPart.Workbook.GetFirstChild<Sheets>().Elements<Sheet>();
// Get relationship Id
string relationshipId = sheetcollection.First().Id.Value;
// Get sheet1 Part of Spread Sheet Document
WorksheetPart worksheetPart = (WorksheetPart)spreadsheetDocument.WorkbookPart.GetPartById(relationshipId);
// Get Data in Excel file
SheetData sheetData = worksheetPart.Worksheet.Elements<SheetData>().First();
IEnumerable<Row> rowcollection = sheetData.Descendants<Row>();
if (rowcollection.Count() == 0)
{
return dt;
}
// Add columns
foreach (Cell cell in rowcollection.ElementAt(0))
{
dt.Columns.Add(GetValueOfCell(spreadsheetDocument, cell));
}
// Add rows into DataTable
foreach (Row row in rowcollection)
{
DataRow temprow = dt.NewRow();
for (int i = 0; i < row.Descendants<Cell>().Count(); i++)
{
temprow[i] = GetValueOfCell(spreadsheetDocument, row.Descendants<Cell>().ElementAt(i));
}
// Add the row to DataTable
// the rows include header row
dt.Rows.Add(temprow);
}
}
// Here remove header row
dt.Rows.RemoveAt(0);
return dt;
}
catch(IOException ex)
{
throw new IOException(ex.Message);
}
}
/// <summary>
/// Get Value in Cell
/// </summary>
/// <param name="spreadsheetdocument">SpreadSheet Document</param>
/// <param name="cell">Cell in SpreadSheet Document</param>
/// <returns>The value in cell</returns>
private static string GetValueOfCell(SpreadsheetDocument spreadsheetdocument, Cell cell)
{
// Get value in Cell
SharedStringTablePart sharedString =spreadsheetdocument.WorkbookPart.SharedStringTablePart;
if (cell.CellValue == null)
{
return string.Empty;
}
string cellValue = cell.CellValue.InnerText;
// The condition that the Cell DataType is SharedString
if (cell.DataType != null && cell.DataType.Value == CellValues.SharedString)
{
return sharedString.SharedStringTable.ChildElements[int.Parse(cellValue)].InnerText;
}
else
{
return cellValue;
}
}
#endregion Import operation
#region Export operation
/// <summary>
/// Export Data in GridView control to Excel file
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void btnExport_Click(object sender, EventArgs e)
{
// Initialize an instance of DataTable
DataTable dt = CreateDataTable(this.gridViewTest);
// Save the exported file
string appPath = Request.PhysicalApplicationPath;
string filename = Guid.NewGuid().ToString() + ".xlsx";
string filePath = appPath+ filename;
new CreateSpreadSheetProvider().ExportToExcel(dt, filePath);
string savefilepath = "Export Excel file successfully, the exported excel file is placed in: " + filePath;
Response.Write("<script language='javascript'>alert('"+savefilepath.Replace("\\","\\\\")+"');</script>");
}
/// <summary>
/// Create DataTable from GridView Control
/// </summary>
/// <param name="girdViewtest">GridView Control</param>
/// <returns>An instance of DataTable Object</returns>
private DataTable CreateDataTable(GridView girdViewtest)
{
dt = new DataTable();
// Get columns from GridView
// Add value of columns to DataTable
try
{
for (int i = 0; i < gridViewTest.HeaderRow.Cells.Count; i++)
{
dt.Columns.Add(gridViewTest.HeaderRow.Cells[i].Text);
}
}
catch
{
throw;
}
// Get rows from GridView
foreach (GridViewRow row in gridViewTest.Rows)
{
DataRow datarow = dt.NewRow();
for (int i = 0; i < row.Cells.Count; i++)
{
datarow[i] = row.Cells[i].Text.Replace(" ", " ");
}
// Add rows to DataTable
dt.Rows.Add(datarow);
}
return dt;
}
#endregion Export operation
}