Bagikan melalui

HtmlElement.GotFocus Kejadian

  • Referensi

Definisi

Ruang nama:
System.Windows.Forms
Rakitan:
System.Windows.Forms.dll

Terjadi ketika elemen telah menerima fokus input pengguna.

public:
 event System::Windows::Forms::HtmlElementEventHandler ^ GotFocus;
public event System.Windows.Forms.HtmlElementEventHandler GotFocus;
public event System.Windows.Forms.HtmlElementEventHandler? GotFocus;
member this.GotFocus : System.Windows.Forms.HtmlElementEventHandler 
Public Custom Event GotFocus As HtmlElementEventHandler

Jenis Acara

HtmlElementEventHandler

Contoh

Simpan kode HTML berikut ke dalam file, dan muat file ke dalam WebBrowser kontrol dalam proyek Formulir Windows.

<HTML>  
    <BODY>  
        <FORM name="form1">  
            <INPUT type="text" size=20 name="text1">  
            <INPUT type="text" size=20 name="text2">  
            <INPUT type="text" size=20 name="text3">  
        </FORM>  
    </BODY>  
</HTML>

Contoh kode berikut mencegah elemen berikutnya INPUT dalam urutan tab menerima fokus input pengguna jika elemen sebelumnya berisi kurang dari lima karakter. Contohnya mengharuskan file HTML yang disebutkan sebelumnya dimuat ke dalam instans WebBrowser kontrol bernama WebBrowser1.

HtmlElement targetFormElement;

private void HandleFormFocus()
{
    if (webBrowser1.Document != null)
    {
        HtmlDocument doc = webBrowser1.Document;
        if (doc.Forms.Count > 0)
        {
            HtmlElement targetForm = doc.Forms[0];
            HtmlElementCollection searchCollection = targetForm.All.GetElementsByName("text1");
            if (searchCollection.Count == 1)
            {
                targetFormElement = searchCollection[0];
            }
        }
    }
}

private void TargetFormElement_Focus(Object sender, HtmlElementEventArgs e)
{
    HtmlElement textElement = e.FromElement;
    String elementText = textElement.GetAttribute("value");

    // Check that this value is at least five characters long.
    if (elementText.Length < 5)
    {
        e.ReturnValue = true;
        MessageBox.Show("The entry in the current field must be at least five characters long.");
    }
}

Dim WithEvents TargetFormElement As HtmlElement

Private Sub HandleFormFocus()
    If (WebBrowser1.Document IsNot Nothing) Then
        With WebBrowser1.Document
            If (.Forms.Count > 0) Then
                Dim TargetForm As HtmlElement = .Forms(0)
                Dim SearchCollection As HtmlElementCollection = TargetForm.All.GetElementsByName("text1")
                If (SearchCollection.Count = 1) Then
                    TargetFormElement = SearchCollection(0)
                End If
            End If
        End With
    End If
End Sub

Private Sub TargetFormElement_Focus(ByVal sender As Object, ByVal e As HtmlElementEventArgs)
    Dim TextElement As HtmlElement = e.FromElement
    Dim ElementText As String = TextElement.GetAttribute("value")

    ' Check that this value is at least five characters long.
    If (ElementText.Length < 5) Then
        e.ReturnValue = True
        MessageBox.Show("The entry in the current field must be at least five characters long.")
    End If
End Sub

Keterangan

Anda tidak dapat membatalkan perilaku default peristiwa ini, atau mencegahnya menggelegak. Untuk menghapus fokus dari elemen, panggil Focus elemen yang berbeda dari dalam GotFocus peristiwa.

Berlaku untuk

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