獲取或設置數據源中要綁定到 Value 控件中各項的 HtmlSelect 屬性的字段。Gets or sets the field from the data source to bind to the Value property of each item in the HtmlSelect control.

public:

virtual property System::String ^ DataValueField { System::String ^ get(); void set(System::String ^ value); };

public virtual string DataValueField { get; set; }

member this.DataValueField : string with get, set

Public Overridable Property DataValueField As String

屬性值

數據源中要綁定到 Value 控件中各項的 HtmlSelect 屬性的字段。The field from the data source to bind to the Value property of each item in the HtmlSelect control. 默認值為空字符串 ("")，指示尚未設置該屬性。The default value is an empty string (""), which indicates that the property has not been set.

示例

The following code example demonstrates how to use the DataSource and DataValueField properties to specify the field from the data source to bind to the ListItem.Value property of each item in the HtmlSelect control.

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HtmlSelect Example

void Page_Load (Object sender, EventArgs e)

{

// Bind the HtmlSelect control to a data source when the page is initially loaded.

if (!IsPostBack)

{

// Open a connection to the database and run the query.

// Note that the connection string may vary depending on your

// database server settings.

string ConnectString = "server=localhost;database=pubs;integrated security=SSPI";

string QueryString = "select * from authors";

SqlConnection myConnection = new SqlConnection(ConnectString);

SqlDataAdapter myCommand = new SqlDataAdapter(QueryString, myConnection);

// Create a dataset to store the query results.

DataSet ds = new DataSet();

myCommand.Fill(ds, "Authors");

// Bind the HtmlSelect control to the data source.

Select1.DataSource = ds;

Select1.DataTextField = "au_fname";

Select1.DataValueField = "au_fname";

Select1.DataBind();

}

}

void Button_Click (Object sender, EventArgs e)

{

// Display the selected items.

Label1.Text = "You selected:";

for (int i=0; i<=Select1.Items.Count - 1; i++)

{

if (Select1.Items[i].Selected)

Label1.Text += "
?? - " + Select1.Items[i].Text;

}

}

HtmlSelect Example

Select items from the list.

Use the Control or Shift key to select multiple items.

multiple="true"

runat="server"/>

onserverclick="Button_Click"

runat="server">

Submit

runat="server"/>

/p>

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

HtmlSelect Example

Sub Page_Load (sender As Object, e As EventArgs)

' Bind the HtmlSelect control to a data source when the page is initially loaded.

If Not IsPostBack Then

' Open a connection to the database and run the query.

' Note that the connection string may vary depending on your

' database server settings.

Dim ConnectString As String = "server=localhost;database=pubs;integrated security=SSPI"

Dim QueryString As String = "select * from authors"

Dim myConnection As SqlConnection = New SqlConnection(ConnectString)

Dim myCommand As SqlDataAdapter = New SqlDataAdapter(QueryString, myConnection)

' Create a dataset to store the query results.

Dim ds As DataSet = New DataSet()

myCommand.Fill(ds, "Authors")

' Bind the HtmlSelect control to the data source.

Select1.DataSource = ds

Select1.DataTextField = "au_fname"

Select1.DataValueField = "au_fname"

Select1.DataBind()

End If

End Sub

Sub Button_Click (sender As Object, e As EventArgs)

Dim i As Integer

Label1.Text = "You selected:"

For i = 0 To Select1.Items.Count - 1

If Select1.Items(i).Selected Then

Label1.Text = Label1.Text & "
?? - " & Select1.Items(i).Text

End If

Next i

End Sub

HtmlSelect Example

Select items from the list.

Use the Control or Shift key to select multiple items.

multiple="true"

runat="server"/>

onserverclick="Button_Click"

runat="server">

Submit

runat="server"/>

The following code example demonstrates how to use the DataSourceID and DataValueField properties to specify the field from the data source to bind to the ListItem.Value property of each item in the HtmlSelect control.

/p>

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

void SubmitButton_Click (object sender, System.EventArgs e)

{

// Iterate through the list items in the

// HtmlSelect control to find the selected item.

for (int i = 0; i <= Select1.Items.Count - 1; i++)

{

if (Select1.Items[i].Selected)

// Display the Value property of the selected item.

// This property is populated by the DataValueField property.

Label1.Text = "The Product ID is " + Select1.Items[i].Value;

}

}

HtmlSelect.DataValueField

HtmlSelect.DataValueField Example 2

Select an item from the list:

name="Select1"

datasourceid="SqlDataSource1"

datatextfield="ProductName"

datavaluefield="ProductID"

runat="server">

connectionstring="workstation id=localhost;integrated security=SSPI;initial catalog=Northwind"

selectcommand="SELECT * FROM [Products] Where ProductID <= 5"

runat="server">

text="Submit"

οnclick="SubmitButton_Click"

runat="Server">

runat="Server">

/p>

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

Sub SubmitButton_Click(ByVal sender As Object, ByVal e As System.EventArgs)

Dim i As Integer

' Iterate through the list items in the

' HtmlSelect control to find the selected item.

For i = 0 To Select1.Items.Count - 1

If Select1.Items(i).Selected Then

' Display the Value property of the selected item.

' This property is populated by the DataValueField property.

Label1.Text = "The Product ID is " & Select1.Items(i).Value

End If

Next i

End Sub

HtmlSelect.DataValueField

HtmlSelect.DataValueField Example 2

Select an item from the list:

name="Select1"

datasourceid="SqlDataSource1"

datatextfield="ProductName"

datavaluefield="ProductID"

runat="server">

connectionstring="workstation id=localhost;integrated security=SSPI;initial catalog=Northwind"

selectcommand="SELECT * FROM [Products] Where ProductID <= 5"

runat="server">

text="Submit"

οnclick="SubmitButton_Click"

runat="Server">

runat="Server">

注解

使用 DataValueField 屬性可指定數據源中要綁定到 ListItem.Value 控件中每個項的屬性的字段。Use the DataValueField property to specify which field from the data source to bind to the ListItem.Value property of each item in the control. This property is commonly used to provide a value for the ListItem.Value property that differs from the value of the ListItem.Text property.

HtmlSelect類提供兩個屬性，用于指定要綁定到的數據源。The HtmlSelect class provides two properties for specifying the data source to bind to. 使用 DataSource 屬性指定數據源時，必須顯式調用 DataBind 方法，將控件及其 DataValueField 屬性綁定到數據源。When you use the DataSource property to specify the data source, you must explicitly call the DataBind method to bind the control and its DataValueField property to the data source.

DataSourceID屬性允許您將 HtmlSelect 控件綁定到表示數據源的數據源控件。The DataSourceID property allows you to bind an HtmlSelect control to a data source control that represents a data source. When you use the DataSourceID property to specify the data source, the HtmlSelect control and its DataValueField property automatically bind to the data source control. 因此，無需顯式調用 DataBind 方法。Therefore, you do not need to explicitly call the DataBind method.

適用于

另請參閱

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