DetailsViewRowCollection.GetEnumerator Metodo

  • Riferimento

Definizione

Spazio dei nomi:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Restituisce un enumeratore contenente tutti gli oggetti DetailsViewRow presenti nell'oggetto DetailsViewRowCollection.

public:
 virtual System::Collections::IEnumerator ^ GetEnumerator();
public System.Collections.IEnumerator GetEnumerator ();
abstract member GetEnumerator : unit -> System.Collections.IEnumerator
override this.GetEnumerator : unit -> System.Collections.IEnumerator
Public Function GetEnumerator () As IEnumerator

Restituisce

IEnumerator

Oggetto implementato IEnumerator contenente tutti gli oggetti DetailsViewRow nell'insieme DetailsViewRowCollection.

Implementazioni

GetEnumerator()

Esempio

Nell'esempio di codice seguente viene illustrato come usare il GetEnumerator metodo per recuperare un enumeratore contenente gli elementi della raccolta. L'enumeratore viene quindi sottoposto a iterazione e il valore di ogni riga viene visualizzato nella pagina.


<%@ 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 SubmitButton_Click(Object sender, EventArgs e)
  {

    // Use the Count property to determine whether the
    // Rows collection contains any item.
    if (ItemDetailsView.Rows.Count > 0)
    {

      MessageLabel.Text = "The row values are: <br/><br/>";

      // Get the enumerator that contains the data rows in the 
      // DetailsView control.
      IEnumerator rowEnumerator = ItemDetailsView.Rows.GetEnumerator();

      // Iterate though the enumerator and display the field values.
      while (rowEnumerator.MoveNext())
      {
        DetailsViewRow row = (DetailsViewRow)rowEnumerator.Current;

        // Use the Text property to access the value of 
        // each cell. In this example, the cells in the 
        // first column (index 0) contains the field names, 
        // while the cells in the second column (index 1)
        // contains the field value. 
        MessageLabel.Text += row.Cells[0].Text + " = " +
          row.Cells[1].Text + "<br/>";
      }

    }
    else
    {
      MessageLabel.Text = "No items.";
    }

  }
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewRowCollection GetEnumerator Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>DetailsViewRowCollection GetEnumerator Example</h3>
  
      <asp:detailsview id="ItemDetailsView"
        datasourceid="DetailsViewSource"
        allowpaging="true"
        autogeneraterows="false" 
        runat="server">
        <fields>
          <asp:boundfield datafield="CustomerID"
            headertext="Customer ID"/>
          <asp:boundfield datafield="CompanyName"
            headertext="Company Name"/>
          <asp:boundfield datafield="Address"
            headertext="Address"/>
          <asp:boundfield datafield="City"
            headertext="City"/>
          <asp:boundfield datafield="PostalCode"
            headertext="ZIP Code"/>
          <asp:boundfield datafield="Country"
            headertext="Country"/>
        </fields>
      </asp:detailsview>
      
      <br/>
      
      <asp:button id="SubmitButton" 
        text="Display Row Values"
        onclick="SubmitButton_Click"
        runat="server"/>
        
      <br/><br/>
      
      <asp:label id="MessageLabel"
        forecolor="Red"
        runat="server"/>
      
      <!-- 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="DetailsViewSource"
        selectcommand="Select [CustomerID], [CompanyName], [Address], 
          [City], [PostalCode], [Country] From [Customers]"
        connectionstring=
          "<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>  
  
    </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 SubmitButton_Click(ByVal sender As Object, ByVal e As EventArgs)

    ' Use the Count property to determine whether the
    ' Rows collection contains any item.
    If ItemDetailsView.Rows.Count > 0 Then

      MessageLabel.Text = "The row values are: <br/><br/>"

      ' Get the enumerator that contains the data rows in the 
      ' DetailsView control.
      Dim rowEnumerator As IEnumerator = ItemDetailsView.Rows.GetEnumerator()

      ' Iterate though the enumerator and display the field values.
      While rowEnumerator.MoveNext()
 
        Dim row As DetailsViewRow = CType(rowEnumerator.Current, DetailsViewRow)

        ' Use the Text property to access the value of 
        ' each cell. In this example, the cells in the 
        ' first column (index 0) contains the field names, 
        ' while the cells in the second column (index 1)
        ' contains the field value. 
        MessageLabel.Text &= row.Cells(0).Text & " = " & _
          row.Cells(1).Text & "<br/>"
      
      End While
    
    Else
    
      MessageLabel.Text = "No items."
        
    End If

  End Sub
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewRowCollection GetEnumerator Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>DetailsViewRowCollection GetEnumerator Example</h3>
  
      <asp:detailsview id="ItemDetailsView"
        datasourceid="DetailsViewSource"
        allowpaging="true"
        autogeneraterows="false" 
        runat="server">
        <fields>
          <asp:boundfield datafield="CustomerID"
            headertext="Customer ID"/>
          <asp:boundfield datafield="CompanyName"
            headertext="Company Name"/>
          <asp:boundfield datafield="Address"
            headertext="Address"/>
          <asp:boundfield datafield="City"
            headertext="City"/>
          <asp:boundfield datafield="PostalCode"
            headertext="ZIP Code"/>
          <asp:boundfield datafield="Country"
            headertext="Country"/>
        </fields>
      </asp:detailsview>
      
      <br/>
      
      <asp:button id="SubmitButton" 
        text="Display Row Values"
        onclick="SubmitButton_Click"
        runat="server"/>
        
      <br/><br/>
      
      <asp:label id="MessageLabel"
        forecolor="Red"
        runat="server"/>
      
      <!-- 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="DetailsViewSource"
        selectcommand="Select [CustomerID], [CompanyName], [Address], 
          [City], [PostalCode], [Country] From [Customers]"
        connectionstring=
          "<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>  
  
    </form>
  </body>
</html>

Commenti

Usare questo metodo per ottenere un enumeratore che può essere iterato in modo lineare per accedere a ogni elemento nell'oggetto DetailsViewRowCollection . Per accedere all'elemento nella posizione corrente nell'enumeratore, usare la Current proprietà . Utilizzare il MoveNext metodo per passare all'elemento successivo nella raccolta. Per spostare l'enumeratore nella posizione iniziale, usare il Reset metodo .

Nota

Quando inizialmente si ottiene l'enumeratore o si usa il Reset metodo per spostare l'enumeratore al primo elemento della raccolta, è necessario chiamare il MoveNext metodo. In caso contrario, l'elemento Current rappresentato dalla proprietà non è definito.

Si applica a

Vedi anche