BaseDataBoundControl.DataSource Eigenschaft

Definition

Ruft das Objekt ab, aus dem das datengebundene Steuerelement seine Liste mit Datenelementen abruft, oder legt dieses fest.Gets or sets the object from which the data-bound control retrieves its list of data items.

public:
 virtual property System::Object ^ DataSource { System::Object ^ get(); void set(System::Object ^ value); };
[System.ComponentModel.Bindable(true)]
[System.Web.UI.Themeable(false)]
public virtual object DataSource { get; set; }
member this.DataSource : obj with get, set
Public Overridable Property DataSource As Object

Eigenschaftswert

Ein Objekt, das die Datenquelle darstellt, aus der das datengebundene Steuerelement seine Daten abruft.An object that represents the data source from which the data-bound control retrieves its data. Die Standardeinstellung ist null.The default is null.

Attribute

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, DataSource wie die-Eigenschaft eines Daten gebundenen Steuer Elements verwendet wird.The following code example demonstrates how the DataSource property of a data-bound control is used. In diesem Beispiel ist das GridView -Steuerelement an ein DataSet -Objekt gebunden.In this example, the GridView control is bound to a DataSet object. Nachdem die DataSource -Eigenschaft festgelegt wurde DataBind , wird die-Methode explizit aufgerufen.After the DataSource property is set, the DataBind method is called explicitly.


<%@ Page language="C#" %>
<%@ import namespace="System.Data" %>
<%@ 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">

  void Page_Load(Object sender, EventArgs e)
  {
    
    // This example uses Microsoft SQL Server and connects
    // to the Northwind sample database. The data source needs
    // to be bound to the GridView control only when the 
    // page is first loaded. Thereafter, the values are
    // stored in view state.                      
    if(!IsPostBack)
    {
        
      // Declare the query string.
      String queryString = 
        "Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]";
        
      // Run the query and bind the resulting DataSet
      // to the GridView control.
      DataSet ds = GetData(queryString);
      if (ds.Tables.Count > 0)
      {
        AuthorsGridView.DataSource = ds;
        AuthorsGridView.DataBind();
      }
      else
      {
        Message.Text = "Unable to connect to the database.";
      }
            
    }     
    
  }
    
  DataSet GetData(String queryString)
  {

    // Retrieve the connection string stored in the Web.config file.
    String connectionString = ConfigurationManager.ConnectionStrings["NorthWindConnectionString"].ConnectionString;      
 
    DataSet ds = new DataSet();
        
    try
    {
      // Connect to the database and run the query.
      SqlConnection connection = new SqlConnection(connectionString);        
      SqlDataAdapter adapter = new SqlDataAdapter(queryString, connection);
        
      // Fill the DataSet.
      adapter.Fill(ds);
            
    }
    catch(Exception ex)
    {
        
      // The connection failed. Display an error message.
      Message.Text = "Unable to connect to the database.";
        
    }
        
    return ds;
        
  }
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView DataBind Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView DataBind Example</h3>
            
      <asp:label id="Message"
        forecolor="Red"
        runat="server"/>
               
      <br/>    

      <asp:gridview id="AuthorsGridView" 
        autogeneratecolumns="true" 
        runat="server">
      </asp:gridview>
                        
    </form>
  </body>
</html>


<%@ Page language="VB" %>
<%@ import namespace="System.Data" %>
<%@ 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 Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    
    ' This example uses Microsoft SQL Server and connects
    ' to the Northwind sample database. The data source needs
    ' to be bound to the GridView control only when the 
    ' page is first loaded. Thereafter, the values are
    ' stored in view state.                      
    If Not IsPostBack Then
        
      ' Declare the query string.
      Dim queryString As String = _
        "Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        
      ' Run the query and bind the resulting DataSet
      ' to the GridView control.
      Dim ds As DataSet = GetData(queryString)
      If (ds.Tables.Count > 0) Then
      
        AuthorsGridView.DataSource = ds
        AuthorsGridView.DataBind()
      
      Else
      
        Message.Text = "Unable to connect to the database."
        
      End If
            
    End If
    
  End Sub
    
  Function GetData(ByVal queryString As String) As DataSet
    
    ' Retrieve the connection string stored in the Web.config file.
    Dim connectionString As String = ConfigurationManager.ConnectionStrings("NorthWindConnectionString").ConnectionString
 
    Dim ds As New DataSet()
        
    Try

      ' Connect to the database and run the query.
      Dim connection As New SqlConnection(connectionString)
      Dim adapter As New SqlDataAdapter(queryString, Connection)
        
      ' Fill the DataSet.
      Adapter.Fill(ds)
            
    
    Catch ex As Exception
        
      ' The connection failed. Display an error message.
      Message.Text = "Unable to connect to the database."
        
    End Try
        
    Return ds
        
  End Function
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView DataBind Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView DataBind Example</h3>
            
      <asp:label id="Message"
        forecolor="Red"
        runat="server"/>
               
      <br/>    

      <asp:gridview id="AuthorsGridView" 
        autogeneratecolumns="true" 
        runat="server">
      </asp:gridview>
                        
    </form>
  </body>
</html>

Hinweise

Wenn Sie die DataSource -Eigenschaft festlegen, ValidateDataSource wird die-Methode aufgerufen.When you set the DataSource property, the ValidateDataSource method is called. Wenn das Daten gebundene Steuerelement bereits initialisiert wurde, wird die OnDataPropertyChanged -Methode aufgerufen, um die RequiresDataBinding -Eigenschaft auf truefestzulegen.In addition, if the data-bound control has already been initialized, the OnDataPropertyChanged method is called to set the RequiresDataBinding property to true.

Diese Eigenschaft kann nicht durch Designs oder Stylesheetdesigns festgelegt werden.This property cannot be set by themes or style sheet themes. Weitere Informationen finden Sie unter ThemeableAttribute und ASP.NET-Designs und Skins.For more information, see ThemeableAttribute and ASP.NET Themes and Skins.

Gilt für:

Siehe auch