TextBox.TextChanged Evento
Definizione
Importante
Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.
Si verifica quando l'utente modifica il testo di un oggetto TextBox. Questa API è obsoleta. Per informazioni su come sviluppare applicazioni per dispositivi mobili ASP.NET, vedere App per dispositivi mobili & Siti con ASP.NET.
public:
event EventHandler ^ TextChanged;
public event EventHandler TextChanged;
member this.TextChanged : EventHandler
Public Custom Event TextChanged As EventHandler
Tipo evento
Esempio
Nell'esempio seguente viene illustrato come usare l'evento TextChanged per modificare gli elementi in un SelectionListoggetto .
<%@ Page Language="C#"
Inherits="System.Web.UI.MobileControls.MobilePage" %>
<%@ Register TagPrefix="mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>
<script runat="server">
void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
// Add items to the list
SelectionList1.Items.Add(new
MobileListItem("Verify transactions","Done"));
SelectionList1.Items.Add(new
MobileListItem("Check balance sheet","Scheduled"));
SelectionList1.Items.Add(new
MobileListItem("Call customer", "Done"));
SelectionList1.Items.Add(new
MobileListItem("Send checks", "Pending"));
SelectionList1.Items.Add(new
MobileListItem("Send report", "Pending"));
SelectionList1.Items.Add(new
MobileListItem("Attend meeting", "Scheduled"));
// Show all items in list
SelectionList1.Rows = SelectionList1.Items.Count;
}
}
void TextChanged(object sender, EventArgs e)
{
// Called during PostBack, if changed
string task = TextBox1.Text;
string status = TextBox2.Text;
if (task.Length > 0 && status.Length > 0)
{
MobileListItem li = new MobileListItem(task, status);
// Remove the item if it exists
if (SelectionList1.Items.Contains(li))
SelectionList1.Items.Remove(li);
else
// Add the item if it does not exist
SelectionList1.Items.Add(li);
// Clear the text boxes
TextBox1.Text = String.Empty;
TextBox2.Text = String.Empty;
}
// Display all items.
SelectionList1.Rows = SelectionList1.Items.Count;
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<body>
<mobile:Form id="Form1" runat="server">
<mobile:Label Id="Label1" runat="server">
Create a new Task with Status</mobile:Label>
<mobile:SelectionList runat="server" BreakAfter="true"
SelectType="ListBox"
id="SelectionList1" />
<mobile:Label Id="Label2" runat="server"
Text="Enter the Task name" />
<mobile:TextBox runat="server" id="TextBox1"
OnTextChanged="TextChanged" />
<mobile:Label Id="Label3" runat="server"
Text="Enter the Task status" />
<mobile:TextBox runat="server" id="TextBox2" />
<mobile:Command ID="Command1" runat="server"
Text="Submit" />
</mobile:Form>
</body>
</html>
<%@ Page Language="VB"
Inherits="System.Web.UI.MobileControls.MobilePage" %>
<%@ Register TagPrefix="mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>
<script runat="server">
Protected Sub Page_Load(ByVal byvalsender As Object, _
ByVal e As EventArgs)
If Not IsPostBack Then
' Add items to the list
SelectionList1.Items.Add(New _
MobileListItem("Verify transactions", "Done"))
SelectionList1.Items.Add(New _
MobileListItem("Check balance sheet", "Scheduled"))
SelectionList1.Items.Add(New _
MobileListItem("Call customer", "Done"))
SelectionList1.Items.Add(New _
MobileListItem("Send checks", "Pending"))
SelectionList1.Items.Add(New _
MobileListItem("Send report", "Pending"))
SelectionList1.Items.Add(New _
MobileListItem("Attend meeting", "Scheduled"))
' Show all items in list
SelectionList1.Rows = SelectionList1.Items.Count
End If
End Sub
Private Sub TextChanged(ByVal sender As Object, _
ByVal e As EventArgs)
' Called during PostBack, if changed
Dim task As String = TextBox1.Text
Dim status As String = TextBox2.Text
If (task.Length > 0 AndAlso status.Length > 0) Then
Dim li As New MobileListItem(task, status)
' Remove the item if it exists
If (SelectionList1.Items.Contains(li)) Then
SelectionList1.Items.Remove(li)
Else
' Add the item if it does not exist
SelectionList1.Items.Add(li)
End If
' Clear the text boxes
TextBox1.Text = String.Empty
TextBox2.Text = String.Empty
End If
' Display all items.
SelectionList1.Rows = SelectionList1.Items.Count
End Sub
</script>
<html xmlns="http:'www.w3.org/1999/xhtml" >
<body>
<mobile:Form id="Form1" runat="server">
<mobile:Label Id="Label1" runat="server">
Create a new Task with Status</mobile:Label>
<mobile:SelectionList runat="server"
SelectType="ListBox"
id="SelectionList1" />
<mobile:Label Id="Label2" runat="server"
Text="Enter the Task name" />
<mobile:TextBox runat="server" id="TextBox1"
OnTextChanged="TextChanged" />
<mobile:Label Id="Label3" runat="server"
Text="Enter the Task status" />
<mobile:TextBox runat="server" id="TextBox2" />
<mobile:Command ID="Command1" runat="server"
Text="Submit" />
</mobile:Form>
</body>
</html>
Commenti
Quando l'utente modifica il testo di un TextBoxevento , questo evento non viene generato immediatamente. Il modulo deve contenere un Command oggetto per avviare un evento postback che genera l'evento TextChanged .