UserControl.LoadViewState(Object) Metode

Definisi

Ruang nama:

System.Web.UI

Rakitan:

System.Web.dll

Memulihkan informasi status tampilan dari permintaan kontrol pengguna sebelumnya yang disimpan oleh SaveViewState() metode .

protected:
 override void LoadViewState(System::Object ^ savedState);

protected override void LoadViewState (object savedState);

override this.LoadViewState : obj -> unit

Protected Overrides Sub LoadViewState (savedState As Object)

Parameter

savedState

Object

Yang Object mewakili status kontrol pengguna yang akan dipulihkan.

Contoh

Contoh berikut menunjukkan kontrol pengguna yang mengelola status tampilannya menggunakan LoadViewState metode dan SaveViewState .

public string UserText
{
    get
    {
        return (string)ViewState["usertext"];
    }
    set
    {
        ViewState["usertext"] = value;
    }
}
public string PasswordText
{
    get
    {
        return (string)ViewState["passwordtext"];
    }
    set
    {
        ViewState["passwordtext"] = value;
    }
}

[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] 
protected override void LoadViewState(object savedState) 
{
    object[] totalState = null;	   
    if (savedState != null)
    {
        totalState = (object[])savedState;
        if (totalState.Length != 3)
        {
            // Throw an appropriate exception.
        }
        // Load base state.
        base.LoadViewState(totalState[0]);
        // Load extra information specific to this control.
        if (totalState != null && totalState[1] != null && totalState[2] != null)
        {
            UserText = (string)totalState[1];
            PasswordText = (string)totalState[2];
        }
    }
}

[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] 
protected override object SaveViewState()
{
    object baseState = base.SaveViewState();
    object[] totalState = new object[3];
    totalState[0] = baseState;
    totalState[1] = user.Text;
    totalState[2] = password.Text;
    return totalState;
}

   
    Public Property UserText() As String

        Get
            Return CStr(ViewState("usertext"))
        End Get
        Set(ByVal value As String)
            ViewState("usertext") = value
        End Set

    End Property
   
    Public Property PasswordText() As String

        Get
            Return CStr(ViewState("passwordtext"))
        End Get
        Set(ByVal value As String)
            ViewState("passwordtext") = value
        End Set

    End Property
   
    <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
    Protected Overrides Sub LoadViewState(ByVal savedState As Object)

        Dim totalState As Object() = Nothing
        If Not (savedState Is Nothing) Then
            totalState = CType(savedState, Object())
            If totalState.Length <> 3 Then
                ' Throw an appropriate exception.
            End If
            ' Load base state.
            MyBase.LoadViewState(totalState(0))
            ' Load extra information specific to this control.
            If Not (totalState Is Nothing) AndAlso Not (totalState(1) Is Nothing) AndAlso Not (totalState(2) Is Nothing) Then
                UserText = CStr(totalState(1))
                PasswordText = CStr(totalState(2))
            End If
        End If

    End Sub
     
    <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
    Protected Overrides Function SaveViewState() As Object

        Dim baseState As Object = MyBase.SaveViewState()
        Dim totalState(2) As Object
        totalState(0) = baseState
        totalState(1) = user.Text
        totalState(2) = password.Text
        Return totalState

    End Function
End Class 

Keterangan

Metode ini digunakan terutama oleh infrastruktur .NET Framework dan tidak dimaksudkan untuk digunakan langsung dari kode Anda. Namun, pengembang kontrol dapat mengambil alih metode ini untuk menentukan bagaimana kontrol server kustom memulihkan status tampilannya. Untuk informasi selengkapnya, lihat Ringkasan Manajemen Status ASP.NET.

Anda dapat memuat nilai status tampilan ke dalam bidang sehingga Anda tidak perlu mengambilnya dari Control.ViewState properti nanti. Anda juga dapat memasukkan nilai ke ViewState properti tepat sebelum memanggil SaveViewState , yang merupakan cara efektif untuk membuat bidang bertahan di seluruh perjalanan pulang pergi ke server.

Lihat juga

• LoadViewState(Object)
• IStateManager.LoadViewState(Object)