C# gridview 将下拉列表绑定到 List<keyvaluePair<int, string>>

gridview bind dropdownlist to List<keyvaluePair<int, string>>

提问by Jon

I have a number of tables in my DB that hold references to an key value pair:

我的数据库中有许多表保存对键值对的引用：

types of phone numbers:

电话号码类型：

• 1 - Home
• 2 - Work
• 3 - Mobile
• 4 - Fax

• 1 - 主页
• 2 - 工作
• 3 - 手机
• 4 - 传真

etc

等等

So I have a table for the types and when they are used in other tables they reference the int value as a foreign key. When I have been pulling them out I have been storing them as keyvaluepair<int, string>items in the class that is using them.

所以我有一个类型表，当它们在其他表中使用时，它们引用 int 值作为外键。当我将它们拉出时，我一直将它们作为keyvaluepair<int, string>项目存储在使用它们的类中。

When I needed to get a list of them I thought I would just create a List<> of them rather than use two different types of data types to get the same data.

当我需要获取它们的列表时，我想我只需创建它们的 List<> 而不是使用两种不同类型的数据类型来获取相同的数据。

My problem has arrived when I need to populate a dropdownlist within a gridview when I am using the edittemplate bit. If I use a datasource to pull this out it will write [1 Home] in the text rather than put the int as the value and Home as the text to display.

当我使用 edittemplate 位时需要在 gridview 中填充下拉列表时，我的问题就出现了。如果我使用数据源将其提取出来，它将在文本中写入 [1 Home] 而不是将 int 作为值并将 Home 作为要显示的文本。

I guess I have a multiple part question really.

我想我真的有一个多部分的问题。

One:

一：

Am I being stupid? Is this a really bad way to get the data out and store it (the keyvaluepair part)? Should I just be storing it all in a datatable? I didn't like to put it all in datatable. I have my DAL taking to my BLL and have tried to encapsulate everything as objects or List<>'s of objects rather than tables of everything. Most the time this has worked well.

我傻吗？这是获取数据并存储它（键值对部分）的一种非常糟糕的方式吗？我应该将它全部存储在数据表中吗？我不喜欢把它全部放在数据表中。我将我的 DAL 带到我的 BLL 并尝试将所有内容封装为对象或对象的List<>'s 而不是所有内容的表。大多数情况下，这运作良好。

Two:

二：

If I was using some object rather than a datatable to bind into my objectdatasource for the dropdownlist, how can I set the currently selected value, rather than have it just have the first item in the list selected?

如果我使用某个对象而不是数据表绑定到下拉列表的对象数据源中，我该如何设置当前选定的值，而不是只选择列表中的第一项？

EDIT

编辑

As was pointed out below I was being an idiot and just needed to set the DataValueField and DataKeyField.

正如下面指出的那样，我是个白痴，只需要设置 DataValueField 和 DataKeyField。

To get the dropdownlist to bind I just had to do:

要绑定下拉列表，我只需要执行以下操作：

SelectedValue='<%# DataBinder.Eval(Container, "DataItem.PhoneType.Key") %>'

The reason I didn't see that one straight away was because it was not showing up in my intellisense but when I manually typed it in, it worked.

我没有立即看到它的原因是因为它没有出现在我的智能感知中，但是当我手动输入它时，它起作用了。

采纳答案by CMS

Use a Dictionary<int, string> and set your DropDown DataValueField to Keyand DataTextField to Value.

使用 Dictionary<int, string> 并将 DropDown DataValueField 设置为Key并将 DataTextField 设置为Value。

    // A sample dictionary:
    var dictionary = new Dictionary<int, string>();
    dictionary.Add(1, "Home");
    dictionary.Add(2, "Work");
    dictionary.Add(3, "Mobile");
    dictionary.Add(4, "Fax");

    // Binding the dictionary to the DropDownList:
    dropDown.DataTextField = "Value";
    dropDown.DataValueField = "Key";
    dropDown.DataSource = dictionary;  //Dictionary<int, string>
    dropDown.DataBind();

回答by mRizvandi

and its my custom method

它是我的自定义方法

// Define enum
public enum ServiceType : int
{
    MinimumService = 1,
    NormalService = 2,
    VipService = 99
}

// custom method to get my custom text name for each enum type
public string GetServiceTypeName(ServiceType serviceType)
{
    string retValue = "";
    switch (serviceType)
    {
        case ServiceType.Print:
            retValue = "We have some services for you";
            break;
        case ServiceType.BookBinding:
            retValue = "We ar glad to meet you";
            break;
        default:
            retValue = "We alywas are ready to make you happy";
            break;
    }
    return retValue;
}

// making dictionary (key and value) for dropdown datasource
public static Dictionary<string, int> GetAllServiceTypeName()
{
    Dictionary<string, int> dataSource = new Dictionary<string, int>();

    foreach (int item in Enum.GetValues(typeof(ServiceType)))
        dataSource.Add(GetServiceTypeName((ServiceType)item), item);

    return dataSource;
}


   // bind the dropdown to dictionary
    ddlServiceType.DataSource = GetAllServiceTypeName();
    ddlServiceType.DataBind();

   // aspx markup code sample
    <asp:DropDownList ID="ddlServiceType" runat="server" 
        DataTextField="Key" DataValueField="Value">
    </asp:DropDownList>