1

我正在尝试创建一个具有附加功能的自定义 GridView，但我确实遇到了由“Button2”“模拟”的 PostBack 问题。在每个 PostBack（在第一个 DataBinding 之后），一个 DataRow 的内容被删除，直到 GridView 完全为空。它与 PreRender 事件中的 AddCustomControls() 有关。但我不知道如何解决这个问题。有人有想法吗？任何帮助将不胜感激。

也许下图比我的话更好地描述了这种行为。

使用 OnLoad 事件中的 DataBind() 和 OnDataBound 事件中的 AddCustomControls，它工作得很好。表在 PostBacks 之间保持完全相同。但是当我尝试实现网格的编辑时，我不能再使用这个“解决方案”（这也不是很优雅）。从逻辑上讲，TextBoxes 中的编辑值被 OnLoad 中的 DataBind() 覆盖。

不知何故，它与“headerTable.Rows.AddAt(1, controlRow);”有关。如果我执行“headerTable.Rows.Add(controlRow);” 它在最后添加了行，一切正常。所以这种标题行之后的内容被清除了......

在此处输入图像描述

网页配置

<configuration>
    <system.web>
        <compilation debug="true" targetFramework="4.0" />
      <pages>
        <controls>
          <add tagPrefix="asp" assembly="WebApplication11" namespace="WebApplication11"/>
        </controls>
      </pages>
    </system.web>
</configuration>

默认.aspx

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:mightygridview
            ID="mightyGridView"
            runat="server"
            AllowSorting="true"
            AllowHiding="true"
            AutoGenerateEditButton="false"
            OnRowUpdating="mightyGridView_RowUpdating">
        </asp:mightygridview>

        <br />

        <asp:Button ID="Button1" runat="server" Text="Button - Binding" onclick="Button1_Click" />
        <asp:Button ID="Button2" runat="server" Text="Button - Nothing" />
    </div>
    </form>
</body>
</html>

默认.aspx.cs

protected void Page_Load(object sender, EventArgs e)
{

}

protected void Button1_Click(object sender, EventArgs e)
{
    DataTable tbl = new DataTable();
    DataRow row;

    tbl.Columns.Add("Spalte A");
    tbl.Columns.Add("Spalte B");
    tbl.Columns.Add("Spalte C");

    row = tbl.NewRow();
    row[0] = "Spalte A, Zeile 1";
    row[1] = "Spalte B, Zeile 1";
    row[2] = "Spalte C, Zeile 1";
    tbl.Rows.Add(row);

    row = tbl.NewRow();
    row[0] = "Spalte A, Zeile 2";
    row[1] = "Spalte B, Zeile 2";
    row[2] = "Spalte C, Zeile 2";
    tbl.Rows.Add(row);

    row = tbl.NewRow();
    row[0] = "Spalte A, Zeile 3";
    row[1] = "Spalte B, Zeile 3";
    row[2] = "Spalte C, Zeile 3";
    tbl.Rows.Add(row);

    mightyGridView.DataSource = tbl;
    mightyGridView.DataBind();
}

MightyGridView.cs

public class MightyGridView : GridView
{
    public MightyGridView()
    {
        _images = new Dictionary<_imageTypes, string>();
        _images.Add(_imageTypes.SortAsc, "data:;base64,iVBORw0KGgoAAAANSUhEUgAAAA0AAAAJCAYAAADpeqZqAAAAAXNSR0IArs4c6QAAAAZiS0dEAP8A/wD/oL2nkwAAAAlwSFlzAAAOwwAADsMBx2+oZAAAAAd0SU1FB9oGEAstLlCBjxcAAABWSURBVBjTY/z45TsDqYCFkYF0wMTAyMiADW/ese8/LjkmbCZt3r73PzKNYRMjAwMDMkZXuHn73v/oalBs2oTDZHRxJph2XBpQNELVMn759pOM0CMDAADRtiJL6bIYOQAAAABJRU5ErkJggg==");
        _images.Add(_imageTypes.SortAscActive, "data:;base64,iVBORw0KGgoAAAANSUhEUgAAAA0AAAAJCAYAAADpeqZqAAAAAXNSR0IArs4c6QAAAAZiS0dEAP8A/wD/oL2nkwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAAd0SU1FB9oHDgckDaeYtVQAAAA1SURBVBjTY/z//z8DqYCJgQyAU5NK2Yb/JGmCacClkYmQDdg0MhHjJHRxJmL8gC7PSLcgBwAAMRqcsjcZIwAAAABJRU5ErkJggg==");
        _images.Add(_imageTypes.SortDesc, "data:;base64,iVBORw0KGgoAAAANSUhEUgAAAA0AAAAJCAYAAADpeqZqAAAAAXNSR0IArs4c6QAAAAZiS0dEAP8A/wD/oL2nkwAAAAlwSFlzAAAOwwAADsMBx2+oZAAAAAd0SU1FB9oGEAstDmvvr98AAABhSURBVBjTY/zy7ScDqYCJgQzA8p/hPwMDAwPDpm17/xNS7OflzAix6T8DA8N/BgY/T4gATg2ezowwtUwYErg0IPsJqhmOfdEU+Ho6M6KrwRoQMI2+OGxm/PTlOzmhRzoAADvsH5oZ616EAAAAAElFTkSuQmCC");
        _images.Add(_imageTypes.SortDescActive, "data:;base64,iVBORw0KGgoAAAANSUhEUgAAAA0AAAAJCAYAAADpeqZqAAAAAXNSR0IArs4c6QAAAAZiS0dEAP8A/wD/oL2nkwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAAd0SU1FB9oHDgckFi39fLgAAABBSURBVBjTY/z//z8DqYCJgQzAAmOolG0gaOWdrgBGFJtgAoQ0YDgPl0Z0cSZCCrAa9P//f6xYuXT9f1xyjHQLcgCoNDp3uWsOTwAAAABJRU5ErkJggg==");
        _images.Add(_imageTypes.HideColumn, "data:;base64,iVBORw0KGgoAAAANSUhEUgAAAA0AAAAJCAYAAADpeqZqAAAAAXNSR0IArs4c6QAAAAZiS0dEAP8A/wD/oL2nkwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAAd0SU1FB9oGEAsyFSzQaK0AAADHSURBVBjThZAxCoNQDIbTnsAbCM4eQfAC4uYstCdwFOd2dXNwFZzcxQtI3+bkrIKz4AW+Ln2l7WtpIJB8yf9DIoAAsq4rVVWx77topnMcR6ZpQvdHecS2bXJTSrIsYxgGNE/TFKWU2LZ90MxwvVwvBEFAXdd4nodSis8dQwTI6XTGsiz6vufb3ABd1+G6Lnme4/v+f9E8zziOQ1mWAFIUxbP+KYqiyHCP49gQPb8nIrIsi4Rh+IokSRJp25Y3+OrQNM3XGz7zDsbcHXO0jDwtAAAAAElFTkSuQmCC");
        _images.Add(_imageTypes.ShowAllColumns, "data:;base64,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");
    }

    private enum _imageTypes { SortAsc, SortAscActive, SortDesc, SortDescActive, HideColumn, ShowAllColumns }
    private readonly Dictionary<_imageTypes, string> _images;

    public new bool AllowSorting { get; set; }
    public bool AllowHiding { get; set; }
    public override object DataSource
    {
        get
        {
            return Page.Session[this.ID + ".DataSource"];
        }

        set
        {
            Page.Session[this.ID + ".DataSource"] = value;
            base.DataSource = value;
        }
    }

    private void AddCustomControlsRow()
    {
        if (DataSource != null)
        {
            if (AllowSorting || AllowHiding)
            {
                DataTable dataTable = GetDataTableFromDataSource();

                if (dataTable.Columns.Count > 0 && dataTable.Rows.Count > 0)
                {
                    if (this.HeaderRow != null && this.HeaderRow.Parent != null)
                    {
                        string sortExpression = dataTable.DefaultView.Sort.Replace(" ASC", "").Replace(" DESC", "");
                        SortDirection sortDirection = dataTable.DefaultView.Sort.EndsWith(" ASC") ? SortDirection.Ascending : SortDirection.Descending;

                        Table headerTable = (Table)this.HeaderRow.Parent;
                        GridViewRow controlRow = new GridViewRow(-1, -1, DataControlRowType.Header, DataControlRowState.Normal);
                        TableCell controlCell;
                        ImageButton imageButton;

                        foreach (TableCell cell in this.HeaderRow.Cells)
                        {
                            // Sicherstellen, dass es nicht die Spalte mit den Bearbeiten-Buttons ist, welche keine Überschrift enthält.
                            if (!(cell.Text.Replace("&nbsp;", "").Trim().Length > 0))
                            {
                                controlCell = new TableCell();

                                cell.Attributes.Add("style", "border-bottom: 0");
                                controlCell.Attributes.Add("style", "border-top: 0; text-align: center");

                                controlRow.Cells.Add(controlCell);
                            }

                            else
                            {
                                controlCell = new TableCell();

                                cell.Attributes.Add("style", "border-bottom: 0");
                                controlCell.Attributes.Add("style", "border-top: 0; text-align: center");

                                if (AllowSorting)
                                {
                                    imageButton = new ImageButton();
                                    imageButton.Attributes.Add("data-column-name", cell.Text);
                                    imageButton.Click += new ImageClickEventHandler(SortColumnAscButton_Click);

                                    if (sortExpression == cell.Text && sortDirection == SortDirection.Ascending)
                                        imageButton.ImageUrl = _images[_imageTypes.SortAscActive];
                                    else
                                        imageButton.ImageUrl = _images[_imageTypes.SortAsc];

                                    controlCell.Controls.Add(imageButton);

                                    imageButton = new ImageButton();
                                    imageButton.Attributes.Add("data-column-name", cell.Text);
                                    imageButton.Click += new ImageClickEventHandler(SortColumnDescButton_Click);

                                    if (sortExpression == cell.Text && sortDirection == SortDirection.Descending)
                                        imageButton.ImageUrl = _images[_imageTypes.SortDescActive];
                                    else
                                        imageButton.ImageUrl = _images[_imageTypes.SortDesc];

                                    controlCell.Controls.Add(imageButton);

                                    controlRow.Cells.Add(controlCell);
                                }

                                if (AllowHiding)
                                {
                                    imageButton = new ImageButton();
                                    imageButton.Attributes.Add("data-column-name", cell.Text);
                                    imageButton.Click += new ImageClickEventHandler(HideColumnButton_Click);
                                    imageButton.ImageUrl = _images[_imageTypes.HideColumn];
                                    controlCell.Controls.Add(imageButton);

                                    controlRow.Cells.Add(controlCell);
                                }
                            }
                        }

                        headerTable.Rows.AddAt(1, controlRow);
                    }
                }
            }
        }
    }

    public static DataTable GetDataTableFromIEnumerable(IEnumerable enumerable)
    {
        DataTable dataTable = new DataTable();
        DataRow row;
        PropertyInfo[] propertyInfos;

        foreach (object obj in enumerable)
        {
            propertyInfos = obj.GetType().GetProperties();

            if (dataTable.Columns.Count == 0)
                foreach (PropertyInfo pi in propertyInfos)
                    dataTable.Columns.Add(pi.Name, pi.PropertyType);

            row = dataTable.NewRow();

            foreach (PropertyInfo pi in propertyInfos)
            {
                object value = pi.GetValue(obj, null);
                row[pi.Name] = value;
            }

            dataTable.Rows.Add(row);
        }

        return dataTable;
    }

    private DataTable GetDataTableFromDataSource()
    {
        DataTable dataTable;

        if (DataSource is DataTable)
            dataTable = (DataTable)DataSource;

        else if (DataSource is IEnumerable)
            dataTable = GetDataTableFromIEnumerable((IEnumerable)DataSource);

        else
            throw new NotSupportedException("Typ wird nicht unterstützt.");

        return dataTable;
    }

    protected override void OnInit(EventArgs e)
    {
        base.OnInit(e);
    }

    protected override void OnLoad(EventArgs e)
    {
        // Weg der funktionierte, jedoch mit Editing Probleme macht: OnLoad: DataBind() / OnDataBound: AddCustomControls.
        // Das DataBinding überschrieb die geänderten Werte wieder.

        base.OnLoad(e);
    }

    protected override void OnDataBinding(EventArgs e)
    {
        base.OnDataBinding(e);
    }

    protected override void OnDataBound(EventArgs e)
    {
        base.OnDataBound(e);
    }

    protected override void OnPreRender(EventArgs e)
    {
        AddCustomControlsRow();

        base.OnPreRender(e);
    }

    protected override void OnUnload(EventArgs e)
    {
        base.OnUnload(e);
    }

    protected void SortColumnAscButton_Click(object sender, ImageClickEventArgs e)
    {
        DataTable dataTable = GetDataTableFromDataSource();
        dataTable.DefaultView.Sort = ((ImageButton)sender).Attributes["data-column-name"] + " ASC";

        DataSource = dataTable;
        DataBind();
    }

    protected void SortColumnDescButton_Click(object sender, ImageClickEventArgs e)
    {
        DataTable dataTable = GetDataTableFromDataSource();
        dataTable.DefaultView.Sort = ((ImageButton)sender).Attributes["data-column-name"] + " DESC";

        DataSource = dataTable;
        DataBind();
    }

    protected void HideColumnButton_Click(object sender, ImageClickEventArgs e)
    {
        // todo: Improve. Backup zum resetten, etc.
        DataTable dataTable = GetDataTableFromDataSource();
        dataTable.Columns.Remove(((ImageButton)sender).Attributes["data-column-name"]);

        DataSource = dataTable;
        DataBind();
    }
4

1 回答 1

0

将其移至 OnRowCreated，它也会在生命周期的每个 PostBack 上触发：

    protected override void OnRowCreated(GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.Header)
        {
            if (AllowSorting || AllowHiding)
                AddHeaderControls(e.Row);
        }

        base.OnRowCreated(e);
    }

它还修复了排序按钮等的行为。单击（排序）按钮不会触发事件，因为 PreRender 中的“绑定”来不及处理事件。我还稍微更改了 AddHeaderControls 方法，而不是添加一整行，而是将控件添加到单元格本身，这是一个片段：

foreach (TableCell cell in row.Cells)
{
    // Sicherstellen, dass es nicht die Spalte mit den Bearbeiten-Buttons ist, welche keine &#220;berschrift enth&#228;lt.
    if (cell.Text.Replace(&quot;&amp;nbsp;&quot;, string.Empty).Trim().Length &gt; 0)
    {
        // Write the Header Text into the cell as a (Literal)Control, because it would be lost otherwise.
        cell.Controls.Add(new LiteralControl(cell.Text));
        cell.Controls.Add(new LiteralControl(&quot;&lt;br /&gt;&quot;));

        if (AllowSorting)
        {
            imageButton = new ImageButton();
            imageButton.Attributes.Add(&quot;data-column-name&quot;, cell.Text);
            imageButton.Click += new ImageClickEventHandler(SortColumnAscButton_Click);
            if (sortExpression == cell.Text &amp;&amp; sortDirection == SortDirection.Ascending)
                imageButton.ImageUrl = _images[_imageTypes.SortAscActive];
            else
                imageButton.ImageUrl = _images[_imageTypes.SortAsc];
            cell.Controls.Add(imageButton);

            imageButton = new ImageButton();
            imageButton.Attributes.Add(&quot;data-column-name&quot;, cell.Text);
            imageButton.Click += new ImageClickEventHandler(SortColumnDescButton_Click);
            if (sortExpression == cell.Text &amp;&amp; sortDirection == SortDirection.Descending)
                imageButton.ImageUrl = _images[_imageTypes.SortDescActive];
            else
                imageButton.ImageUrl = _images[_imageTypes.SortDesc];
            cell.Controls.Add(imageButton);
        }

        if (AllowHiding)
        {
            imageButton = new ImageButton();
            imageButton.Attributes.Add(&quot;data-column-name&quot;, cell.Text);
            imageButton.Click += new ImageClickEventHandler(HideColumnButton_Click);
            imageButton.ImageUrl = _images[_imageTypes.HideColumn];
            cell.Controls.Add(imageButton);
        }
    }
}
于 2012-06-21T07:06:03.830 回答