以编程方式查看和处理objectdatasource的选择数据 [英] view and process objectdatasource's select data programmatically

问题描述

我有一个复选框列表，该列表是从包含所有报纸的数据源中填充的.我想查看和比较其选择数据的第二个数据源包含收藏夹报纸.

我想根据第二个数据源中的报纸ID预选复选框.它的select方法返回的数据是可枚举的.并且复选框的值为字符串.

如何比较属于复选框的值和来自第二个数据源的选择数据?

我尝试以下解决方案，但未检查任何cbs:

 受保护的 无效 CheckBoxList1_DataBound(对象发​​件人，EventArgs e)
        {
            IEnumerable结果= favoriteDataSource.Select();
             foreach ( var 项目 in 结果中的项)
            {
                 foreach (ListItem cb  in  CheckBoxList1.Items)
                {
                    如果(item.ToString()== cb.Value)
                    {
                        cb.Selected =  true ;
                    }
                }
            } 

 cb将报纸名称保存为文本，将ids保留为值.所以我想比较身份证.
这是数据源(收藏夹数据源)
 坍塌
<   asp:ObjectDataSource     ID   ="   runat   服务器" 
          OldValuesParameterFormatString   ="  original_ {0}" 
          SelectMethod   ="  GetfavoritesByContactId"  TypeName    myapp.FavoritesBLL" <   SelectParameters  > 
        <   asp:QueryStringParameter    名称  ="   QueryStringField    contactid " 
                     span>          ="   Int32" / > 
    <  /SelectParameters  > 
<  /asp:ObjectDataSource  > 
这是填充了另一个数据源(报纸数据源)的复选框列表.没问题，所有cb都已填充.
 坍塌
<   asp:CheckBoxList     ID   ="   runat   服务器" 
                   span>    DataSourceID   ="  NewspaperDatasource"  DataTextField    npName" 
                     span>    DataValueField   =" 报纸编号"  ondatabound    CheckBoxList1_DataBound" <  /asp:CheckBoxList  > 
这是我尝试比较报纸ID的代码.
 坍塌
受保护的void CheckBoxList1_DataBound(对象发送者，EventArgs e)
        {
            IEnumerable结果= favoriteDataSource.Select();
            foreach(结果中的可变项)
            {
                foreach(CheckBoxList1.Items中的ListItem cb)
                {
                    如果(item.ToString()== cb.Value)
                    {
                        cb.Selected = true;
                    }
                }
            }
        }
我认为ienumerable存在问题.

解决方案

我只是在这里猜测，因此您必须自己尝试一下，但是似乎item.ToString() ^1.给出了您最喜欢的报纸之一的名称，并且在所有复选框中都为报纸的名称
将位于属性cb.Text中.

这都是猜测，因为我们还没有看到初始化asp:checkbox实例的代码，也没有在所有报纸上都能读到的代码.我仍然认为cb.Text可能会解决问题.

 受保护的 无效 CheckBoxList1_DataBound(对象发​​件人，EventArgs e)
        {
            IEnumerable结果= favoriteDataSource.Select();
             foreach ( var 项目 in 结果中的项)
            {
                 foreach (ListItem cb  in  CheckBoxList1.Items)
                {
                    // 将该cb.Text代替cb.Value 
                    // 项目的确切类型是什么?那你就会知道
                    // 使用什么属性将其与cb.Text进行比较
                    如果(item.ToString()== cb.Text)
                    {
                        cb.Selected =  true ;
                    }
                }
            } 

脚注:

1.如果FavoritsDataSource.Select()返回了您自己编写的类型的对象列表，则很有可能ToString()方法将只返回那些对象的类名以外的任何有意义的信息.
脚注

最好的问候，
曼弗雷德(Manfred)

i have a checkboxlist populated from a datasource which contains all newspapers. a second datasource which i want to view and compare its select data, contains favorites newspapers.

i want checkboxes preselected according to newspaper ids from the second datasources. its select method returns data as ienumarable. and the values of checkboxes are strings.

how can i compare the values belong to checkboxes and the select data from the second datasource ?

i try the following solution but none of cbs is checked :

protected void CheckBoxList1_DataBound(object sender, EventArgs e)
        {
            IEnumerable results = FavoritesDataSource.Select();
            foreach (var item in results)
            {
                foreach (ListItem cb in CheckBoxList1.Items)
                {
                    if (item.ToString()== cb.Value)
                    {
                        cb.Selected = true;
                    }
                }
            }

cb is holding newspaper names as text and ids as value. so i want to compare ids.
this is the datasource ( favorites datasource )
 Collapse
<asp:ObjectDataSource ID="FavoritesDataSource" runat="server"

    OldValuesParameterFormatString="original_{0}"

    SelectMethod="GetfavoritesByContactId" TypeName="myapp.FavoritesBLL">
    <SelectParameters>
        <asp:QueryStringParameter Name="contactid" QueryStringField="contactid"

            Type="Int32" />
    </SelectParameters>
</asp:ObjectDataSource>
this is the checkboxlist populated with another data source (newspapers data source ). there is no problem with that, all cbs are populated.
 Collapse
<asp:CheckBoxList ID="CheckBoxList1" runat="server"

        DataSourceID="NewspaperDatasource" DataTextField="npName"

        DataValueField="newspaperid" ondatabound="CheckBoxList1_DataBound">
    </asp:CheckBoxList>
and this is the code i try to compare newspaper ids.
 Collapse
protected void CheckBoxList1_DataBound(object sender, EventArgs e)
        {
            IEnumerable results = FavoritesDataSource.Select();
            foreach (var item in results)
            {
                foreach (ListItem cb in CheckBoxList1.Items)
                {
                    if (item.ToString()== cb.Value)
                    {
                        cb.Selected = true;
                    }
                }
            }
        }
i think there's a problem with ienumerable.

解决方案

I''m only guessing here so you''ll have to try it out yourself, but it would seem that the item.ToString()^1. gives you the name of one of the favorite newspapers and in all the checkboxes the name of the newspaper
would be in the property cb.Text.

This is all guesswork as we didn''t see the code yet that initialized the asp:checkbox instances and neither the code that reads in all the newspapers. I still think that cb.Text probably does the trick.

protected void CheckBoxList1_DataBound(object sender, EventArgs e)
        {
            IEnumerable results = FavoritesDataSource.Select();
            foreach (var item in results)
            {
                foreach (ListItem cb in CheckBoxList1.Items)
                {
                    // Make that cb.Text instead of cb.Value
                    // what exactly is the type of item? Then you'd know
                    // what property to use to compare it to cb.Text
                    if (item.ToString() == cb.Text)
                    {
                        cb.Selected = true;
                    }
                }
            }

Footnotes:

1. If FavoritsDataSource.Select() returned a list of objects of a type you wrote yourself, chances are good the ToString() method will not return anything sensible at all but the class name of those objects.
End Footnotes

Best Regards,
Manfred

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