DataControlField.HeaderText Property

Definition

Ottiene o imposta il testo visualizzato nell'elemento dell'intestazione di un campo di controllo dati.Gets or sets the text that is displayed in the header item of a data control field.

public:
 virtual property System::String ^ HeaderText { System::String ^ get(); void set(System::String ^ value); };
public virtual string HeaderText { get; set; }
member this.HeaderText : string with get, set
Public Overridable Property HeaderText As String

Property Value

String

Stringa che viene visualizzata nell'elemento di intestazione dell'oggetto DataControlField.A string that is displayed in the header item of the DataControlField.

Examples

Nell'esempio di codice riportato di seguito viene illustrato come impostare in modo dichiarativo le proprietà HeaderText delle colonne BoundField per visualizzare il testo nelle intestazioni di colonna di un controllo GridView.The following code example demonstrates how to declaratively set the HeaderText properties of BoundField columns to display text in the column headers of a GridView control. Questo esempio di codice illustra uno scenario Master-Details in cui viene usato un controllo GridView per visualizzare un subset di dati mentre il controllo DetailsView viene usato per visualizzare un set di dati più ampio e inserire nuovi record.This code example demonstrates a master-details scenario in which a GridView control is used to display a subset of data while the DetailsView control is used to display a larger set of data and insert new records. Nell'esempio vengono usati due controlli SqlDataSource: uno per popolare il controllo GridView e uno per popolare il controllo DetailsView e inserire i dati.The example uses two SqlDataSource controls: one to populate the GridView control and one to populate the DetailsView control and insert data.

<%@Page  Language="C#" %>
<%@Import Namespace="System.Data" %>
<%@Import Namespace="System.Data.Common" %>
<%@Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
 private void On_Inserting(Object sender, SqlDataSourceCommandEventArgs e) {

    SqlParameter insertedKey = new SqlParameter("@PK_New", SqlDbType.Int);
    insertedKey.Direction    = ParameterDirection.Output;        
    e.Command.Parameters.Add(insertedKey);
 }

 private void On_Inserted(Object sender, SqlDataSourceStatusEventArgs e) {
    DbCommand command = e.Command;    
    
    // The label displays the primary key of the recently inserted row.
    Label1.Text = command.Parameters["@PK_New"].Value.ToString();
    
    // Force a refresh after the data is inserted.
    GridView1.DataBind();
 }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <asp:GridView
        id="GridView1"
        runat="server"
        AutoGenerateColumns="False"
        DataKeyNames="EmployeeID"        
        DataSourceID="SqlDataSource1">
        <columns>          
          <asp:BoundField HeaderText="First Name" DataField="FirstName" />
          <asp:BoundField HeaderText="Last Name" DataField="LastName" />
          <asp:BoundField HeaderText="Title" DataField="Title" />
          <asp:ButtonField ButtonType="Link" CommandName="Select" Text="Details..." />
        </columns>
      </asp:GridView>

      <asp:SqlDataSource
        id="SqlDataSource1"
        runat="server"
        ConnectionString="<%$ ConnectionStrings:MyNorthwind %>"
        SelectCommand="SELECT EmployeeID,FirstName,LastName,Title FROM Employees">
      </asp:SqlDataSource>

      <hr />

      <asp:DetailsView
        id="DetailsView1"
        runat="server"
        DataSourceID="SqlDataSource2"
        AutoGenerateRows="False"
        AutoGenerateInsertButton="True">
        <fields>
          <asp:BoundField HeaderText="First Name" DataField="FirstName" ReadOnly="False"/>
          <asp:BoundField HeaderText="Last Name" DataField="LastName" ReadOnly="False"/>
          <asp:TemplateField HeaderText="Title">
            <ItemTemplate>
              <asp:DropDownList
                id="TitleDropDownList"
                runat="server"
                selectedvalue="<%# Bind('Title') %>" >
                <asp:ListItem Selected="True">Sales Representative</asp:ListItem>
                <asp:ListItem>Sales Manager</asp:ListItem>
                <asp:ListItem>Vice President, Sales</asp:ListItem>
              </asp:DropDownList>
            </ItemTemplate>
          </asp:TemplateField>
          <asp:BoundField HeaderText="Notes" DataField="Notes" ReadOnly="False"/>
        </fields>
      </asp:DetailsView>


      <asp:SqlDataSource
        id="SqlDataSource2"
        runat="server"
        ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
        SelectCommand="SELECT * FROM Employees"
        InsertCommandType = "StoredProcedure"
        InsertCommand="sp_insertemployee"        
        OnInserting="On_Inserting"
        OnInserted ="On_Inserted"
        FilterExpression="EmployeeID={0}">
        <FilterParameters>
          <asp:ControlParameter Name="EmployeeID" ControlId="GridView1" PropertyName="SelectedValue" />
        </FilterParameters>
      </asp:SqlDataSource>

<!-- 
     -- An example sp_insertemployee stored procedure that returns
     -- the primary key of the row that was inserted in an OUT parameter.
     CREATE PROCEDURE sp_insertemployee 
        @FirstName nvarchar(10), 
        @LastName nvarchar(20) , 
        @Title nvarchar(30), 
        @Notes nvarchar(200), 
        @PK_New int OUTPUT
      AS
        INSERT INTO Employees(FirstName,LastName,Title,Notes)VALUES (@FirstName,@LastName,@Title,@Notes)
        SELECT @PK_New = @@IDENTITY
        RETURN (1)    
      GO
-->      

      <asp:Label 
        id="Label1"
        runat="server" />
      
    </form>
  </body>
</html>
<%@Page  Language="VB" %>
<%@Import Namespace="System.Data" %>
<%@Import Namespace="System.Data.Common" %>
<%@Import Namespace="System.Data.SqlClient" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

 Sub On_Inserting(ByVal sender As Object, ByVal e As SqlDataSourceCommandEventArgs)

    Dim insertedKey As SqlParameter  
    insertedKey = New SqlParameter("@PK_New", SqlDbType.Int)
    insertedKey.Direction    = ParameterDirection.Output     
    
    e.Command.Parameters.Add(insertedKey)

 End Sub 'On_Inserting

 Sub On_Inserted(ByVal sender As Object, ByVal e As SqlDataSourceStatusEventArgs)
    Dim command As DbCommand 
    command = e.Command
    
    ' The label displays the primary key of the recently inserted row.
    Label1.Text = command.Parameters("@PK_New").Value.ToString()    
    
    ' Explicitly call DataBind to refresh the data
    ' and show the newly inserted row.
    GridView1.DataBind()
 End Sub 'On_Inserted

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <asp:GridView
        id="GridView1"
        runat="server"
        AutoGenerateColumns="False"
        DataKeyNames="EmployeeID"        
        DataSourceID="SqlDataSource1">
        <columns>          
          <asp:BoundField HeaderText="First Name" DataField="FirstName" />
          <asp:BoundField HeaderText="Last Name" DataField="LastName" />
          <asp:BoundField HeaderText="Title" DataField="Title" />
          <asp:ButtonField ButtonType="Link" CommandName="Select" Text="Details..." />
        </columns>
      </asp:GridView>

      <asp:SqlDataSource
        id="SqlDataSource1"
        runat="server"
        ConnectionString="<%$ ConnectionStrings:MyNorthwind %>"
        SelectCommand="SELECT EmployeeID,FirstName,LastName,Title FROM Employees">
      </asp:SqlDataSource>

      <hr />

      <asp:DetailsView
        id="DetailsView1"
        runat="server"
        DataSourceID="SqlDataSource2"
        AutoGenerateRows="False"
        AutoGenerateInsertButton="True">
        <fields>
          <asp:BoundField HeaderText="First Name" DataField="FirstName" ReadOnly="False"/>
          <asp:BoundField HeaderText="Last Name" DataField="LastName" ReadOnly="False"/>
          <asp:TemplateField HeaderText="Title">
            <ItemTemplate>
              <asp:DropDownList
                id="TitleDropDownList"
                runat="server"
                selectedvalue="<%# Bind('Title') %>" >
                <asp:ListItem Selected="True">Sales Representative</asp:ListItem>
                <asp:ListItem>Sales Manager</asp:ListItem>
                <asp:ListItem>Vice President, Sales</asp:ListItem>
              </asp:DropDownList>
            </ItemTemplate>
          </asp:TemplateField>
          <asp:BoundField HeaderText="Notes" DataField="Notes" ReadOnly="False"/>
        </fields>
      </asp:DetailsView>


      <asp:SqlDataSource
        id="SqlDataSource2"
        runat="server"
        ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
        SelectCommand="SELECT * FROM Employees"
        InsertCommandType = "StoredProcedure"
        InsertCommand="sp_insertemployee"        
        OnInserting="On_Inserting"
        OnInserted ="On_Inserted"
        FilterExpression="EmployeeID={0}">
        <FilterParameters>
          <asp:ControlParameter Name="EmployeeID" ControlId="GridView1" PropertyName="SelectedValue" />
        </FilterParameters>
      </asp:SqlDataSource>

<!-- 
     -- An example sp_insertemployee stored procedure that returns
     -- the primary key of the row that was inserted in an OUT parameter.
     CREATE PROCEDURE sp_insertemployee 
        @FirstName nvarchar(10), 
        @LastName nvarchar(20) , 
        @Title nvarchar(30), 
        @Notes nvarchar(200), 
        @PK_New int OUTPUT
      AS
        INSERT INTO Employees(FirstName,LastName,Title,Notes)VALUES (@FirstName,@LastName,@Title,@Notes)
        SELECT @PK_New = @@IDENTITY
        RETURN (1)    
      GO
-->      

      <asp:Label 
        id="Label1"
        runat="server" />
      
    </form>
  </body>
</html>

Remarks

Utilizzare la proprietà HeaderText per identificare un campo in un controllo dati con un nome descrittivo.Use the HeaderText property to identify a field in a data control with a friendly name. L'applicazione più comune della proprietà HeaderText consiste nel fornire nomi di colonna significativi per i campi associati a dati in un controllo GridView o DetailsView.The most common application of the HeaderText property is to provide meaningful column names for data-bound fields in a GridView or DetailsView control.

Note

Se vengono impostate entrambe le proprietà HeaderText e HeaderImageUrl, la proprietà HeaderImageUrl avrà la precedenza.If both the HeaderText and HeaderImageUrl properties are set, the HeaderImageUrl property has precedence.

Il valore di questa proprietà, se impostato, può essere salvato automaticamente in un file di risorse tramite uno strumento di progettazione.The value of this property, when set, can be saved automatically to a resource file by using a designer tool. Per ulteriori informazioni, vedere LocalizableAttribute e globalizzazione e localizzazione.For more information, see LocalizableAttribute and Globalization and Localization.

Applies to

See also