asp.net - 带有寻呼机 TopAndBottom 的 GridView

Question

我在 ASP.NET 中扩展了标准的 GridView 控件。基本上是一样的，但是分页和排序是使用回调完成的。

我已成功创建自己的 PagerTemplate，但它仅在 PagerSettings.Position 设置为 Top 时有效。我想在顶部和底部都有寻呼机。

我收到一个 HttpException 消息:表格必须包含按页眉、正文和页脚顺序排列的行部分。

有人知道这是什么吗？

我已经尝试调用 MakeAccessible() 方法，但这没有帮助。

代码:

private int _IdColumnIndex = -1;

public override object DataSource
{
  get
  {
    return HttpContext.Current.Session[this.ClientID + "_DataSource"];
  }
  set
  {
    if (!value.GetType().Equals(typeof(DataView)))
      throw new ArgumentException("Only System.Data.DataView is accepted as a DataSource for DataGridView!");

    HttpContext.Current.Session[this.ClientID + "_DataSource"] = value;
  }
}

/// <summary>
/// Sets the default settings.
/// </summary>
private void SetDefaultSettings()
{
  base.AllowPaging = true;
  base.AllowSorting = true;
  base.ShowHeader = true;
  base.ShowFooter = true;
  base.PagerTemplate = new GridPagerTemplate(PAGER_ID, this);
  base.PagerSettings.Position = PagerPosition.TopAndBottom;
  base.PageSize = 10;

  AddSelectionCheckbox();
}

//private void MakeAccessible()
//{
//  if (this.Rows.Count > 0)
//  {
//    //This replaces <td> with <th> and adds the scope attribute 
//    this.UseAccessibleHeader = true;

//    //This will add the <thead> and <tbody> elements
//    this.HeaderRow.TableSection = TableRowSection.TableHeader;

//    //This adds the <tfoot> element. Remove if you don't have a footer row 
//    this.FooterRow.TableSection = TableRowSection.TableFooter;
//  }
//} 

private void AddSelectionCheckbox()
{
  TemplateField tf = new TemplateField();
  tf.HeaderText = "";
  tf.ItemTemplate = new CheckboxTemplate(ROW_CHECKBOX_ID);

  base.Columns.Add(tf);
}

protected override void OnInit(EventArgs e)
{
  SetDefaultSettings();

  base.DataBound += new EventHandler(DataGridView_DataBound);
  base.RowDataBound += new GridViewRowEventHandler(DataGridView_RowDataBound);

  base.OnInit(e);
}

protected override void OnPreRender(EventArgs e)
{
  base.OnPreRender(e);
  //this.PaintRows();
  //this.FormatCells();

  // Get JavaScript for this DataGridView, and include it on the page.
  string scriptUrl = Page.ClientScript.GetWebResourceUrl(this.GetType(), "Yakinix.UI.Controls.DataGridView.js");
  Page.ClientScript.RegisterClientScriptInclude("DataGridView", scriptUrl);

  string js = "function DGV_MakeCallback(argument)" +
              "{" +
                  "__theFormPostData = '';" +
                  "__theFormPostCollection = new Array();" +
                  "WebForm_InitCallback();" +
                  GetCallbackEventReference("DGV_Callback") +
              ";}";

  Page.ClientScript.RegisterClientScriptBlock(typeof(DataGridView), typeof(DataGridView).FullName + "DGV_MakeCallback", js, true);

  if (this.HeaderRow != null)
    this.HeaderRow.TableSection = TableRowSection.TableHeader;
}

private string GetCallbackEventReference(string func)
{
  string callbackEventReference = Page.ClientScript.GetCallbackEventReference(this, "argument", func, "'" + ClientID + "'", false);

  return callbackEventReference;
}

public override void RenderBeginTag(HtmlTextWriter writer)
{
  writer.RenderBeginTag(HtmlTextWriterTag.Div); // <div>
  base.RenderBeginTag(writer);
}

public override void RenderEndTag(HtmlTextWriter writer)
{
  base.RenderEndTag(writer);
  writer.RenderEndTag(); // </div>
}

/// <summary>
/// Renders the gridview control and strips whitespace. It also
/// applies the right formatting.
/// </summary>
public string RenderHtml()
{
  using (StringWriter sw = new StringWriter(CultureInfo.InvariantCulture))
  {
    //this.PaintRows();
    //this.FormatCells();

    if (this.HeaderRow != null)
      this.HeaderRow.TableSection = TableRowSection.TableHeader;

    this.UseAccessibleHeader = true;
    this.RenderControl(new HtmlTextWriter(sw));
    string html = sw.ToString();

    return html;
  }
}

// TODO: Style all rows for the column matching current SortExpression.
protected void DataGridView_RowDataBound(object sender, GridViewRowEventArgs e)
{
  //DataGridView gridView = (DataGridView)sender;

  //if (gridView.SortExpression.Length > 0)
  //{
  //  int cellIndex = -1;

  //  //  find the column index for the corresponding sort expression
  //  foreach (DataControlField field in gridView.Columns)
  //  {
  //    if (field.SortExpression == gridView.SortExpression)
  //    {
  //      cellIndex = gridView.Columns.IndexOf(field);
  //      break;
  //    }
  //  }

  //  if (cellIndex > -1)
  //  {
  //    if (e.Row.RowType == DataControlRowType.Header)
  //    {
  //      //  this is a header row,
  //      //  set the sort style
  //      e.Row.Cells[cellIndex].CssClass += (gridView.SortDirection == SortDirection.Ascending ? " sortascheader" : " sortdescheader");
  //    }
  //    else if (e.Row.RowType == DataControlRowType.DataRow)
  //    {
  //      //  this is a data row
  //      e.Row.Cells[cellIndex].CssClass += (e.Row.RowIndex % 2 == 0 ? " sortaltrow" : "sortrow");
  //    }
  //  }
  //}

  RenderDetailsRow(e);
}

/// <summary>
/// Renders the details row, which is hidden when rendered. Clicking a details link, displays the row and more detailed data is shown, and is editable.
/// </summary>
/// <param name="e">The <see cref="System.Web.UI.WebControls.GridViewRowEventArgs"/> instance containing the event data.</param>
private void RenderDetailsRow(GridViewRowEventArgs e)
{
  // Only add a details row to DataRows
  if (false && e.Row.RowType == DataControlRowType.DataRow)
  {
    Table table = e.Row.Parent as Table;

    if (table != null)
    {
      GridViewRow row = new GridViewRow(-1, -1, DataControlRowType.DataRow, DataControlRowState.Normal);
      row.Style[HtmlTextWriterStyle.Display] = "none";

      TableCell rowCell = new TableCell();
      rowCell.ColumnSpan = this.Columns.Count;
      rowCell.Height = new Unit(100);

      row.Cells.Add(rowCell);
      table.Rows.Add(row);

      HtmlAnchor htmlAhref = new HtmlAnchor();
      htmlAhref.HRef = "javascript:void(0);";
      htmlAhref.Attributes.Add("onclick", "ToggleElement('" + row.ClientID + "');");
      htmlAhref.InnerText = "Test";

      e.Row.Cells[e.Row.Cells.Count - 1].Controls.Add(htmlAhref);
    }
  }
}

protected void DataGridView_DataBound(object sender, EventArgs e)
{
  FillPagerDetails(base.TopPagerRow);
  FillPagerDetails(base.BottomPagerRow);
}

private void FillPagerDetails(GridViewRow pagerRow)
{
  if (pagerRow != null)
  {
    // Retrieve the DropDownList and Label controls from the row.
    DropDownList pageList = pagerRow.Cells[0].FindControl(PAGER_ID) as DropDownList;

    if (pageList != null)
    {
      pageList.Attributes.Add("onchange", "DataGridViewPage(this.value, '" + ClientID + "');");

      // Add the number of pages to the ListBox
      for (int i = 0; i < base.PageCount; i++)
      {
        int pageNumber = i + 1;

        // Create a ListItem that represents a page
        ListItem item = new ListItem(String.Format("{0}", pageNumber), i.ToString());

        // If the page is already selected, make sure the 
        // ListBox select the selected page
        if (i == base.PageIndex)
          item.Selected = true;

        // Add the ListItem object to the Items collection of the DropDownList.
        pageList.Items.Add(item);
      }
    }
  }
}

protected override void InitializeRow(GridViewRow row, DataControlField[] fields)
{
  base.InitializeRow(row, fields);

  if (row.RowType == DataControlRowType.Header)
  {
    for (int i = 0; i < row.Cells.Count; i++)
    {
      row.Cells[i].Controls.Clear();

      if (row.Cells[i].Text.Equals("CHKCOL", StringComparison.Ordinal))
      {
        CheckBox chkSelectAll = new CheckBox();
        chkSelectAll.ID = "chkSelectAllRows";
        row.Cells[i].Controls.Add(chkSelectAll);
      }
      else
      {
        row.Cells[i].Text = String.Format(CultureInfo.InvariantCulture, "<a href=\"javaScript:DataGridViewSort('{0}', '{2}');void(0)\" title=\"{1}\">{1}</a>", fields[i].SortExpression, fields[i].HeaderText, this.ClientID);
      }
    }
    //if (ViewState["SortExpression"] != null)
    //{
    //  int index;
    //  index = 0;// GetHeaderCellIndex(ViewState["SortExpression"].ToString());
    //  if (index != -1)
    //  {
    //    //Literal literal;
    //    //if ((SortDirection)ViewState["SortDirection"] == SortDirection.Ascending)
    //    //{
    //    //  if (string.IsNullOrEmpty(SortAscendingImageUrl))
    //    //  {
    //    //    literal = new Literal();
    //    //    literal.Text = "&#8593;";
    //    //    row.Cells[index].Controls.Add(literal);
    //    //  }
    //    //  else
    //    //  {
    //    //    sortImage.ImageUrl = SortAscendingImageUrl;
    //    //    row.Cells[index].Controls.Add(sortImage);
    //    //  }
    //    //}
    //    //else
    //    //{
    //    //  if (string.IsNullOrEmpty(SortDescendingImageUrl))
    //    //  {
    //    //    literal = new Literal();
    //    //    literal.Text = "&#8595;";
    //    //    row.Cells[index].Controls.Add(literal);
    //    //  }
    //    //  else
    //    //  {
    //    //    sortImage.ImageUrl = SortDescendingImageUrl;
    //    //    row.Cells[index].Controls.Add(sortImage);
    //    //  }
    //    //}
    //  }
    //}
  }
  else if (row.RowType == DataControlRowType.DataRow)
  {
    for (int i = 0; i < row.Cells.Count; i++)
    {
      if (fields[i].HeaderText.Equals("id", StringComparison.InvariantCultureIgnoreCase))
      {
        _IdColumnIndex = i;
        break;
      }
    }
  }
}

protected override void OnRowCreated(GridViewRowEventArgs e)
{
  base.OnRowCreated(e);

  if (e.Row.RowType == DataControlRowType.Header)
  {
    //HtmlImage img = new HtmlImage();
    //img.ID = "lbCheckAll";
    //img.Src = "/img/btn_slct_all.gif";
    //img.Alt = "Select all";
    //img.Attributes.Add("onclick", "SelectAllRows('" + this.ClientID + "',true);return false;");
    //e.Row.Cells[0].Controls.Add(img);
  }
  else if (e.Row.RowType == DataControlRowType.DataRow)
  {
    //AddCheckbox(e);
  }
  else if (e.Row.RowType == DataControlRowType.Footer)
  {
    //e.Row.Cells[0].Text = "sdsds";
  }
}

protected override void OnRowDataBound(GridViewRowEventArgs e)
{
  base.OnRowDataBound(e);

  if (e.Row.RowType == DataControlRowType.DataRow)
  {
    //AddCheckbox(e);

    if (_IdColumnIndex != -1)
      e.Row.Cells[_IdColumnIndex].Text = "<a href=\"Details.aspx?id=" + e.Row.Cells[_IdColumnIndex].Text + "\">Edit</a>";
  }
}

public override void Sort(string sortExpression, SortDirection sortDirection)
{
  DataView dv = this.DataSource as DataView;

  if (dv != null)
  {
    dv.Sort = sortExpression + " " + (sortDirection == SortDirection.Ascending ? "ASC" : "DESC");
  }
}

#region ICallbackEventHandler Members

private string callbackArg = String.Empty;

string ICallbackEventHandler.GetCallbackResult()
{
  // Save state with PageStatePersister and place it to Page.ClientState
  System.Reflection.MethodInfo mi = typeof(Page).GetMethod("SaveAllState", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
  mi.Invoke(this.Page, null);

  // Get serialized viewstate from Page's ClientState
  System.Reflection.PropertyInfo stateProp = typeof(Page).GetProperty("ClientState", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
  string state = stateProp.GetValue(this.Page, null).ToString();

  return callbackArg + "¤#¤" + state;
}

void ICallbackEventHandler.RaiseCallbackEvent(string eventArgument)
{
  try
  {
    // Load XML from client
    XmlDocument doc = new XmlDocument();
    doc.LoadXml(eventArgument.Replace("&", "&amp;"));
    string pagerId = String.Empty;

    if (doc.DocumentElement.Name == "callback")
    {
      string gridId = doc.DocumentElement["arguments"]["gridId"].InnerText;

      switch (doc.DocumentElement["action"].InnerText)
      {
        case "sort":
          string sortExpression = doc.DocumentElement["arguments"]["sortExpression"].InnerText;
          Sort(sortExpression.Split(' ')[0].Trim(), sortExpression.Split(' ')[1].Trim().Equals("ASC") ? SortDirection.Ascending : SortDirection.Descending);
          break;

        case "page":
          string pageIndex = doc.DocumentElement["arguments"]["pageIndex"].InnerText;
          this.PageIndex = Convert.ToInt32(pageIndex);
          pagerId = base.BottomPagerRow.Cells[0].FindControl(PAGER_ID).ClientID;
          break;

        case "search":
          break;
      }

      this.DataBind();
      callbackArg = String.Format("{0}¤|¤{1}¤|¤{2}", gridId, this.RenderHtml(), pagerId);
    }

    doc = null;
  }
  catch (Exception ex)
  {
    callbackArg = String.Format(AJAX_ERROR_FORMAT, ex.Message + "\n\n" + ex.StackTrace);
  }
  finally
  {
    if (callbackArg.Equals(string.Empty))
    {
      callbackArg = String.Format(AJAX_ERROR_FORMAT, "An AJAX Error occurred!");
    }
  }
}

#endregion

Answer 1

这对我有用。必须将 PagerRows 设置到它们适当的部分。

我从 http://www.codeproject.com/Members/iguigova?msg=3153516(搜索 MakeAccessible)

protected override void OnPreRender(EventArgs e)
{
    base.OnPreRender(e);

    if (Rows.Count > 0)
    {
        UseAccessibleHeader = true;
        HeaderRow.TableSection = TableRowSection.TableHeader;
        FooterRow.TableSection = TableRowSection.TableFooter;
    }

    if (TopPagerRow != null)
    {
        TopPagerRow.TableSection = TableRowSection.TableHeader;
    }
    if (BottomPagerRow != null)
    {
        BottomPagerRow.TableSection = TableRowSection.TableFooter;
    }
}