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DetailsViewRowCollection.Count Proprietà

Definizione

Ottiene il numero di elementi nell'oggetto DetailsViewRowCollection.

public:
 property int Count { int get(); };
public int Count { get; }
member this.Count : int
Public ReadOnly Property Count As Integer

Valore della proprietà

Int32

Numero di elementi presenti nel controllo DetailsViewRowCollection.

Implementazioni

Esempio

Nell'esempio di codice seguente viene illustrato come usare la Count proprietà per determinare se un DetailsViewRowCollection oggetto contiene elementi prima di eseguire l'iterazione tramite la raccolta.


<%@ 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)
    {
      // Iterate through the Rows collection and display
      // the value of each field.
      MessageLabel.Text = "The row values are: <br/><br/>";

      foreach (DetailsViewRow row in ItemDetailsView.Rows)
      {
        // 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 Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>DetailsViewRowCollection 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
    
      ' Iterate through the Rows collection and display
      ' the value of each field.
      MessageLabel.Text = "The row values are: <br/><br/>"
    
      Dim row As DetailsViewRow
    
      For Each row In ItemDetailsView.Rows
    
        ' 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/>"
    
      Next
    
    Else
      
      MessageLabel.Text = "No items."
    
    End If
    
  End Sub
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewRowCollection Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>DetailsViewRowCollection 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

Utilizzare la Count proprietà per determinare il numero di elementi nella raccolta. La Count proprietà viene comunemente usata durante l'iterazione tramite la raccolta per determinare il relativo limite superiore. La Count proprietà viene comunemente usata anche per determinare se una raccolta è vuota.

Si applica a

Vedi anche