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基本上我想为网格视图实现一个过滤选项，我有一个包含列名的下拉列表和一个包含该列可用过滤值的复选框列表。每次我选择不同的列时，我都必须将该列的过滤值加载到复选框列表中。我遇到的问题是，当我更改下拉列表中的列时，会触发清单事件并且应用程序崩溃。

我的控件定义如下：

<div class="LeftAligned">  
     <asp:Label ID="FilterLabel" runat="server" Text="Filter by:" />  
     <asp:DropDownList runat="server" ID="FilterReviewsDropDownList" AutoPostBack="true" OnSelectedIndexChanged="FilterReviewsDropDownList_SelectedIndexChanged" />  
     <asp:ImageButton ID="FilterReviewsButton" runat="server" ImageUrl="~/images/filter.png" AlternateText="VALUE" CssClass="filter_button" OnClick="FilterReviewsButton_Click" />  
     <div onmouseout="javascript:bMouseOver=false;" onmouseover="javascript:bMouseOver=true;" class="filter_div">  
           <asp:CheckBoxList AutoPostBack="true" ID="FilterReviewsCheckBoxList" ClientIDMode="Static" runat="server" CssClass="filter_checklist collapsed"   
            OnSelectedIndexChanged="FilterReviewsCheckBoxList_Selected">  
           </asp:CheckBoxList>  
     </div>  
     <%--asp:Button runat="server" ID="ApplyFilterButton" Text="Apply Filter" OnClick="ApplyFilterButton_Click"/>  
     <asp:Button runat="server" ID="ClearFilterButton" Text="Clear Filter" OnClick="ClearFilterButton_Click"/--%>  
</div>

在 CodeBehind 文件中，我有以下代码：

protected void FilterReviewsButton_Click(object sender, EventArgs e)
{
    FilterReviewsCheckBoxList.CssClass = "filter_checklist";
}

protected void FilterReviewsDropDownList_SelectedIndexChanged(object sender, EventArgs e)
{
    LoadFilterCheckboxes(FilterReviewsDropDownList.SelectedIndex);
}

private void LoadFilterCheckboxes(int iColumn)
{
    SortedSet<string> oItems = new SortedSet<string>();

    for (int i = 0; i < ReviewsGridView.Rows.Count; i++)
    {
        IEnumerable<Label> oLabels = ReviewsGridView.Rows[i].Cells[iColumn].Controls.OfType<Label>();
        string sValue = "";
        if (oLabels != null && oLabels.Count() > 0)
        {
            sValue = oLabels.First().Text;
        }
        else
        {
            sValue = ReviewsGridView.Rows[i].Cells[iColumn].Text;
        }
        if (!oItems.Contains(sValue))
            oItems.Add(sValue);
    }

    FilterReviewsCheckBoxList.Items.Clear();
    FilterReviewsCheckBoxList.Items.Add("All");
    FilterReviewsCheckBoxList.Items[0].Selected = true;
    foreach (string sItem in oItems)
    {
        FilterReviewsCheckBoxList.Items.Add(sItem);
        FilterReviewsCheckBoxList.Items[FilterReviewsCheckBoxList.Items.Count - 1].Selected = true;
    }
}

protected void FilterReviewsCheckBoxList_Selected(object sender, EventArgs e)
{
    string sResult = Request.Form["__EVENTTARGET"];
    if (string.IsNullOrEmpty(sResult))
    {
        FilterReviewsCheckBoxList.Items[0].Selected = true; //weird bug fix...
        return;
    }

    string[] sCheckedBox = sResult.Split('$');
    //get the index of the item that was checked/unchecked
     int i = int.Parse(sCheckedBox[sCheckedBox.Length - 1].Split('_')[1]);
     if (i == 0)
     {
         if (FilterReviewsCheckBoxList.Items[i].Selected == true)
         {
             for (int j = 1; j < FilterReviewsCheckBoxList.Items.Count; j++)
                 FilterReviewsCheckBoxList.Items[j].Selected = true;
         }
         else
         {
            for (int j = 1; j < FilterReviewsCheckBoxList.Items.Count; j++)
                FilterReviewsCheckBoxList.Items[j].Selected = false;
         }
     }
     else
     {
        if (FilterReviewsCheckBoxList.Items[i].Selected == false)
        {
            FilterReviewsCheckBoxList.Items[0].Selected = false;
        }
        else
        {
            //if (oFirstTable != null)
            //{
            //    oTable = oFirstTable;
            //    oView = oTable.DefaultView;
            //}
            bool bAllChecked = true;
            for (int j = 1; j < FilterReviewsCheckBoxList.Items.Count; j++)
            {
                 if (FilterReviewsCheckBoxList.Items[j].Selected == false)
                 {
                     bAllChecked = false;
                     break;
                 }
            }
            if (bAllChecked)
                 FilterReviewsCheckBoxList.Items[0].Selected = true;
        }
    }
}

知道为什么在更改下拉列表时调用FilterReviewsCheckBoxList_Selected（将下拉列表作为发件人参数）吗？

4

1 回答 1

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对于可能遇到相同问题的任何人，解决方法是避免将网格视图静态绑定到实体数据源。相反，在页面加载事件中动态绑定网格。

于 2012-06-28T06:29:38.097 回答