GridViewRowCollection.Count Proprietà
Definizione
Importante
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Ottiene il numero di elementi nell'oggetto GridViewRowCollection.
public:
property int Count { int get(); };
public int Count { get; }
member this.Count : int
Public ReadOnly Property Count As Integer
Valore della proprietà
Il numero di elementi nell'oggetto GridViewRowCollection.
Implementazioni
Esempio
Nell'esempio seguente viene illustrato come utilizzare la Count proprietà per determinare se il GridView controllo contiene record. Un valore maggiore di zero indica che il GridView controllo contiene almeno un record.
<%@ 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 AuthorsGridView_RowCreated(Object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.Footer)
{
// Get the number of items in the Rows collection.
int count = AuthorsGridView.Rows.Count;
// If the GridView control contains any records, display
// the last name of each author in the GridView control.
if (count > 0)
{
Message.Text = "The authors are:<br />";
foreach (GridViewRow row in AuthorsGridView.Rows)
{
Message.Text += row.Cells[0].Text + "<br />";
}
}
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridViewRowCollection Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridViewRowCollection Example</h3>
<table>
<tr>
<td>
<asp:gridview id="AuthorsGridView"
datasourceid="AuthorsSqlDataSource"
autogeneratecolumns="false"
onrowcreated="AuthorsGridView_RowCreated"
runat="server">
<columns>
<asp:boundfield datafield="au_lname"
headertext="Last Name"/>
<asp:boundfield datafield="au_fname"
headertext="First Name"/>
</columns>
</asp:gridview>
</td>
<td>
<asp:label id="Message"
forecolor="Red"
runat="server"/>
</td>
</tr>
</table>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Pubs sample database. -->
<asp:sqldatasource id="AuthorsSqlDataSource"
selectcommand="SELECT [au_lname], [au_fname] FROM [authors] WHERE [state]='CA'"
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 AuthorsGridView_RowCreated(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
If e.Row.RowType = DataControlRowType.Footer Then
' Get the number of items in the Rows collection.
Dim count As Integer = AuthorsGridView.Rows.Count
' If the GridView control contains any records, display
' the last name of each author in the GridView control.
If count > 0 Then
Message.Text = "The authors are:<br />"
Dim row As GridViewRow
For Each row In AuthorsGridView.Rows
Message.Text &= row.Cells(0).Text & "<br />"
Next
End If
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridViewRowCollection Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridViewRowCollection Example</h3>
<table>
<tr>
<td>
<asp:gridview id="AuthorsGridView"
datasourceid="AuthorsSqlDataSource"
autogeneratecolumns="false"
onrowcreated="AuthorsGridView_RowCreated"
runat="server">
<columns>
<asp:boundfield datafield="au_lname"
headertext="Last Name"/>
<asp:boundfield datafield="au_fname"
headertext="First Name"/>
</columns>
</asp:gridview>
</td>
<td>
<asp:label id="Message"
forecolor="Red"
runat="server"/>
</td>
</tr>
</table>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Pubs sample database. -->
<asp:sqldatasource id="AuthorsSqlDataSource"
selectcommand="SELECT [au_lname], [au_fname] FROM [authors] WHERE [state]='CA'"
connectionstring="server=localhost;database=pubs;integrated security=SSPI"
runat="server">
</asp:sqldatasource>
</form>
</body>
</html>
Commenti
Utilizzare la Count proprietà per determinare il numero di elementi nell'insieme. La Count proprietà viene comunemente utilizzata durante l'iterazione dell'insieme per determinare il limite superiore dell'insieme. La Count proprietà viene utilizzata comunemente anche per determinare se una raccolta è vuota.