6

我在 GridView 控件中有一个 TemplateField，例如：

<asp:TemplateField ItemStyle-Width="150px">
   <ItemTemplate>
      <asp:DropDownList ID="ddlFields" runat="server" DataSourceID="odsOperator" DataTextField="Text" DataValueField="Value" />
      <asp:HiddenField ID="hfFieldType" runat="server" Value='<%# Eval("FieldType")%>' />
   </ItemTemplate>
</asp:TemplateField>

我有一个要从 ObjectDataSource 填充的下拉列表，但是对于每一行我想传递一个 Select 参数，以便它填充正确的值

<asp:ObjectDataSource ID="odsOperator" runat="server" TypeName="OperatorFieldsDAO"
   SelectMethod="FindByType">      
   <SelectParameters>
      <asp:ControlParameter ControlID="hfFieldType" Type="String" Name="Type" PropertyName="Value" />
   </SelectParameters>
</asp:ObjectDataSource>

我的 OperatorFieldsDAO 类是：

public class OperatorFieldsDAO
{
    private List<OperatorField> OperatorFields
    {
        get
        {
            List<OperatorField> operatorFields = HttpContext.Current.Session["OperatorFields"] as List<OperatorField>;
            if (operatorFields == null)
            {
                operatorFields = new List<OperatorField>();
                operatorFields.Add(new OperatorField("string", "contains", "C"));
                operatorFields.Add(new OperatorField("string", "begins with", "BW"));
                operatorFields.Add(new OperatorField("string", "is equal to", "E"));
                operatorFields.Add(new OperatorField("string", "is not equal to", "NE"));
                operatorFields.Add(new OperatorField("string", "is less than", "L"));
                operatorFields.Add(new OperatorField("string", "is greater than", "G"));
                operatorFields.Add(new OperatorField("string", "is less than or equal to", "LE"));
                operatorFields.Add(new OperatorField("string", "is greater than or equal to", "GE"));
                operatorFields.Add(new OperatorField("string", "is from", "F"));
                operatorFields.Add(new OperatorField("string", "is between", "B"));
                operatorFields.Add(new OperatorField("string", "is nothing", "N"));
                operatorFields.Add(new OperatorField("string", "is something", "S"));

                operatorFields.Add(new OperatorField("number", "is the same as", "S"));
                operatorFields.Add(new OperatorField("number", "is not the same as", "S"));
                operatorFields.Add(new OperatorField("number", "is one of", "S"));
                operatorFields.Add(new OperatorField("number", "is not one of", "S"));
                operatorFields.Add(new OperatorField("number", "is nothing", "N"));
                operatorFields.Add(new OperatorField("number", "is something", "S"));
            }
            return operatorFields;
        }
    }
    public OperatorFieldsDAO() { }

    [DataObjectMethod(DataObjectMethodType.Select)]
    public IEnumerable<OperatorField> FindAll()
    {
        return this.OperatorFields;
    }

    [DataObjectMethod(DataObjectMethodType.Select)]
    public IEnumerable<OperatorField> FindByType(String type)
    {    
        List<OperatorField> r = new List<OperatorField>();

        foreach (OperatorField f in this.OperatorFields)
            if (f.Type == type)
                r.Add(f);

        return r;
    }
}

所有这些都是为了告诉你我收到了一个错误：

在 ControlParameter 'Type' 中找不到控件 'hfFieldType'。

我究竟做错了什么？

我是否需要使用OnRowDataBound方法以编程方式传递所选参数？

4

3 回答 3

5

为了让它工作，我添加了两个方法（一个用于 GridView，另一个用于 ObjectDataSource），并将 Select Parameter 从 ControlParameter 更改为普通参数。

这个想法是在每次创建行时设置参数......

protected void gvSearch_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        DropDownList d = (DropDownList)e.Row.FindControl("ddlFields");
        string type = ((HiddenField)e.Row.FindControl("hfFieldType")).Value;

        _type = type;
        d.DataBind();
    }
}
protected void odsOperator_Selecting(object sender, ObjectDataSourceSelectingEventArgs e)
{
    e.InputParameters["Type"] = _type;
}

private string _type = "";

和 ObjectDataSource 将是

<asp:ObjectDataSource ID="odsOperator" runat="server" TypeName="OperatorFieldsDAO"
   SelectMethod="FindByType" onselecting="odsOperator_Selecting">
   <SelectParameters>
      <asp:Parameter Type="String" Name="Type" />
   </SelectParameters>
</asp:ObjectDataSource>

我希望它可以帮助任何人...

于 2009-08-07T06:36:15.653 回答
1

既然你有：

<asp:HiddenField ID="hfFieldType" runat="server" .../>

在TemplateField您的视图中，页面上可能没有、一个或多个该字段的实例。因此hfFieldType不会是唯一的 ID，实际上实际 ID 将在运行时确定。

因此，您的控件参数无法找到它，因为它正在hfFieldType页面上某处调用的控件的属性中查找其值。

几年来我没有使用过 ObjectDataSource，但我怀疑您可能想加入Selecting事件。

于 2009-08-06T10:36:01.967 回答
0

ObjectDataSource 找不到用于输入的控件，除非它在标记附近。数据源必须位于包含用于输入的控件的标签内。这似乎是一个范围界定问题。

于 2012-05-11T20:07:40.090 回答