GridViewUpdateEventHandler Delegát

Reference

Definice

Obor názvů:: System.Web.UI.WebControls

Sestavení:: System.Web.dll

Důležité

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Představuje metodu, která zpracovává RowUpdating událost ovládacího prvku GridView .

public delegate void GridViewUpdateEventHandler(System::Object ^ sender, GridViewUpdateEventArgs ^ e);

public delegate void GridViewUpdateEventHandler(object sender, GridViewUpdateEventArgs e);

type GridViewUpdateEventHandler = delegate of obj * GridViewUpdateEventArgs -> unit

Public Delegate Sub GridViewUpdateEventHandler(sender As Object, e As GridViewUpdateEventArgs)

Parametry

sender: Object

Zdroj události

e: GridViewUpdateEventArgs

Objekt GridViewUpdateEventArgs , který obsahuje data události.

Příklady

Následující příklad ukazuje, jak programově přidat GridViewUpdateEventHandler delegáta RowUpdating k události GridView ovládacího prvku.


<%@ Page language="C#" %>

<!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)
    {
        
        // Create a new GridView object.
        GridView authorGridView = new GridView();
         
        // Set the GridView object's properties.
        authorGridView.ID = "AuthorGridView";
        authorGridView.DataSourceID = "AuthorsSqlDataSource"; 
        authorGridView.AutoGenerateColumns = true;
        authorGridView.AutoGenerateEditButton = true;
        authorGridView.DataKeyNames = new String[] {"au_id"};
        
        // Programmatically register the event-handling method.
        authorGridView.RowUpdating += new GridViewUpdateEventHandler(this.AuthorsGridView_RowUpdating);
        
        // Add the GridView object to the Controls collection
        // of the PlaceHolder control.
        GridViewPlaceHolder.Controls.Add(authorGridView);
        
    }
    
    void AuthorsGridView_RowUpdating(Object sender, GridViewUpdateEventArgs e)
    {
     
        // HTML-encode all user-provided values before updating
        // the data source.
        foreach (DictionaryEntry entry in e.NewValues)
        {
    
            e.NewValues[entry.Key] = Server.HtmlEncode(entry.Value.ToString());
    
        }
        
    }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server">
    <title>GridViewUpdateEventHandler Example</title>
</head>
<body>
        <form id="form1" runat="server">
        
            <h3>GridViewUpdateEventHandler Example</h3>
            
            <asp:label id="Message"
                forecolor="Red"
                runat="server"/>
                
            <br/>
            
            <asp:placeholder id="GridViewPlaceHolder"
                runat="Server"/>
            
            <!-- This example uses Microsoft SQL Server and connects -->
            <!-- to the Pubs sample database.                        -->
            <asp:sqldatasource id="AuthorsSqlDataSource"  
                selectcommand="SELECT [au_id], [au_lname], [au_fname], [address], [city], [state], [zip] FROM [authors]"
                updatecommand="UPDATE authors SET au_lname=@au_lname, au_fname=@au_fname, address=@address, city=@city, state=@state, zip=@zip WHERE (authors.au_id = @au_id)"
                connectionstring="server=localhost;database=pubs;integrated security=SSPI"
                runat="server">
            </asp:sqldatasource>
            
        </form>
    </body>
</html>


<%@ Page language="VB" %>

<!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)
        
        ' Create a new GridView object.
        Dim authorGridView As GridView = New GridView
         
        ' Set the GridView object's properties.
        authorGridView.ID = "AuthorGridView"
        authorGridView.DataSourceID = "AuthorsSqlDataSource"
        authorGridView.AutoGenerateColumns = True
        authorGridView.AutoGenerateEditButton = True
        authorGridView.DataKeyNames = New [String]() {"au_id"}
        
        ' Programmatically register the event-handling method.
        AddHandler authorGridView.RowUpdating, AddressOf AuthorsGridView_RowUpdating
        
        ' Add the GridView object to the Controls collection
        ' of the PlaceHolder control.
        GridViewPlaceHolder.Controls.Add(authorGridView)
        
    End Sub
    
    Sub AuthorsGridView_RowUpdating(ByVal sender As Object, ByVal e As GridViewUpdateEventArgs)
     
        ' HTML-encode all user-provided values before updating
        ' the data source.
        Dim i As Integer
        
        For i = 0 To e.NewValues.Count - 1
            
            Dim entry As DictionaryEntry = e.NewValues(i)
            e.NewValues(entry.Key) = Server.HtmlEncode(entry.Value.ToString())
    
        Next i
        
    End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server">
    <title>GridViewUpdateEventHandler Example</title>
</head>
<body>
        <form id="form1" runat="server">
        
            <h3>GridViewUpdateEventHandler Example</h3>
            
            <asp:label id="Message"
                forecolor="Red"
                runat="server"/>
                
            <br/>
            
            <asp:placeholder id="GridViewPlaceHolder"
                runat="Server"/>
            
            <!-- This example uses Microsoft SQL Server and connects -->
            <!-- to the Pubs sample database.                        -->
            <asp:sqldatasource id="AuthorsSqlDataSource"  
                selectcommand="SELECT [au_id], [au_lname], [au_fname], [address], [city], [state], [zip] FROM [authors]"
                updatecommand="UPDATE authors SET au_lname=@au_lname, au_fname=@au_fname, address=@address, city=@city, state=@state, zip=@zip WHERE (authors.au_id = @au_id)"
                connectionstring="server=localhost;database=pubs;integrated security=SSPI"
                runat="server">
            </asp:sqldatasource>
            
        </form>
    </body>
</html>

Následující příklad ukazuje, jak deklarativně přidat GridViewUpdateEventHandler delegáta k RowUpdating události GridView ovládacího prvku.


<%@ Page language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void CustomersGridView_RowUpdating(Object sender, GridViewUpdateEventArgs e)
  {
     
    // Iterate through the NewValues collection and HTML encode all 
    // user-provided values before updating the data source.
    foreach (DictionaryEntry entry in e.NewValues)
    {
    
      e.NewValues[entry.Key] = Server.HtmlEncode(entry.Value.ToString());
    
    }
        
  }
       
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView RowUpdating Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView RowUpdating Example</h3>
            
      <!-- The GridView control automatically sets the columns     -->
      <!-- specified in the datakeynames property as read-only.    -->
      <!-- No input controls are rendered for these columns in     -->
      <!-- edit mode.                                              -->
      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSqlDataSource" 
        autogeneratecolumns="true"
        autogenerateeditbutton="true"
        allowpaging="true" 
        datakeynames="CustomerID"
        onrowupdating="CustomersGridView_RowUpdating"  
        runat="server">
      </asp:gridview>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSqlDataSource"  
        selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        updatecommand="Update Customers SET CompanyName=@CompanyName, Address=@Address, City=@City, PostalCode=@PostalCode, Country=@Country WHERE (CustomerID = @CustomerID)"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
        runat="server">
      </asp:sqldatasource>
            
    </form>
  </body>
</html>


<%@ Page language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  Sub CustomersGridView_RowUpdating(ByVal sender As Object, ByVal e As GridViewUpdateEventArgs)
    
    ' Use the CopyTo method to copy the DictionaryEntry objects in the 
    ' NewValues collection to an array.
    Dim records(e.NewValues.Count - 1) As DictionaryEntry
    e.NewValues.CopyTo(records, 0)
    
    ' Iterate through the array and HTML encode all user-provided values 
    ' before updating the data source.
    Dim entry As DictionaryEntry
    For Each entry In records
            
      e.NewValues(entry.Key) = Server.HtmlEncode(entry.Value.ToString())
      
    Next
        
  End Sub
       
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView RowUpdating Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView RowUpdating Example</h3>
            
      <!-- The GridView control automatically sets the columns     -->
      <!-- specified in the datakeynames property as read-only.    -->
      <!-- No input controls are rendered for these columns in     -->
      <!-- edit mode.                                              -->
      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSqlDataSource" 
        autogeneratecolumns="true"
        autogenerateeditbutton="true"
        allowpaging="true" 
        datakeynames="CustomerID"
        onrowupdating="CustomersGridView_RowUpdating"  
        runat="server">
      </asp:gridview>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSqlDataSource"  
        selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        updatecommand="Update Customers SET CompanyName=@CompanyName, Address=@Address, City=@City, PostalCode=@PostalCode, Country=@Country WHERE (CustomerID = @CustomerID)"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
        runat="server">
      </asp:sqldatasource>
            
    </form>
  </body>
</html>

Poznámky

Událost RowUpdating se vyvolá po kliknutí na tlačítko Aktualizovat na řádku, ale před tím, než GridView ovládací prvek řádek aktualizuje. To vám umožní poskytnout metodu zpracování událostí, která provádí vlastní rutinu, například zrušení operace aktualizace, kdykoli dojde k této události.

Při vytváření delegáta GridViewUpdateEventHandler identifikujete metodu, která bude událost zpracovávat. Pokud chcete událost přidružit k obslužné rutině události, přidejte do události instanci delegáta. Obslužná rutina události je volána při každém výskytu události, dokud neodeberete delegáta. Další informace o delegátech obslužné rutiny událostí najdete v tématu Zpracování a vyvolávání událostí.

Metody rozšíření

GetMethodInfo(Delegate)

Získá objekt, který představuje metodu reprezentovanou zadaným delegátem.

Platí pro