LayoutEngine.Layout(Object, LayoutEventArgs) Método

public:
 virtual bool Layout(System::Object ^ container, System::Windows::Forms::LayoutEventArgs ^ layoutEventArgs);

public virtual bool Layout(object container, System.Windows.Forms.LayoutEventArgs layoutEventArgs);

abstract member Layout : obj * System.Windows.Forms.LayoutEventArgs -> bool
override this.Layout : obj * System.Windows.Forms.LayoutEventArgs -> bool

Public Overridable Function Layout (container As Object, layoutEventArgs As LayoutEventArgs) As Boolean

Parâmetros

Devoluções

true se o layout for realizado novamente pelo pai de container; caso contrário, false.

Exceções

Exemplos

O exemplo de código seguinte demonstra a utilização do Layout método para implementar um comportamento de layout personalizado. Este exemplo de código faz parte de um exemplo maior fornecido para a LayoutEngine classe.

public:
    virtual bool Layout(Object^ container,
        LayoutEventArgs^ layoutEventArgs) override
    {
        Control^ parent = nullptr;
        try
        {
            parent = (Control ^) container;
        }
        catch (InvalidCastException^ ex)
        {
            throw gcnew ArgumentException(
                "The parameter 'container' must be a control", "container", ex);
        }
        // Use DisplayRectangle so that parent.Padding is honored.
        Rectangle parentDisplayRectangle = parent->DisplayRectangle;
        Point nextControlLocation = parentDisplayRectangle.Location;

        for each (Control^ currentControl in parent->Controls)
        {
            // Only apply layout to visible controls.
            if (!currentControl->Visible)
            {
                continue;
            }

            // Respect the margin of the control:
            // shift over the left and the top.
            nextControlLocation.Offset(currentControl->Margin.Left,
                currentControl->Margin.Top);

            // Set the location of the control.
            currentControl->Location = nextControlLocation;

            // Set the autosized controls to their
            // autosized heights.
            if (currentControl->AutoSize)
            {
                currentControl->Size = currentControl->GetPreferredSize(
                    parentDisplayRectangle.Size);
            }

            // Move X back to the display rectangle origin.
            nextControlLocation.X = parentDisplayRectangle.X;

            // Increment Y by the height of the control
            // and the bottom margin.
            nextControlLocation.Y += currentControl->Height +
                currentControl->Margin.Bottom;
        }

        // Optional: Return whether or not the container's
        // parent should perform layout as a result of this
        // layout. Some layout engines return the value of
        // the container's AutoSize property.

        return false;
    }

public override bool Layout(
    object container,
    LayoutEventArgs layoutEventArgs)
{
    Control parent = container as Control;

    // Use DisplayRectangle so that parent.Padding is honored.
    Rectangle parentDisplayRectangle = parent.DisplayRectangle;
    Point nextControlLocation = parentDisplayRectangle.Location;

    foreach (Control c in parent.Controls)
    {
        // Only apply layout to visible controls.
        if (!c.Visible)
        {
            continue;
        }

        // Respect the margin of the control:
        // shift over the left and the top.
        nextControlLocation.Offset(c.Margin.Left, c.Margin.Top);

        // Set the location of the control.
        c.Location = nextControlLocation;

        // Set the autosized controls to their 
        // autosized heights.
        if (c.AutoSize)
        {
            c.Size = c.GetPreferredSize(parentDisplayRectangle.Size);
        }

        // Move X back to the display rectangle origin.
        nextControlLocation.X = parentDisplayRectangle.X;

        // Increment Y by the height of the control 
        // and the bottom margin.
        nextControlLocation.Y += c.Height + c.Margin.Bottom;
    }

    // Optional: Return whether or not the container's 
    // parent should perform layout as a result of this 
    // layout. Some layout engines return the value of 
    // the container's AutoSize property.

    return false;
}

Public Overrides Function Layout( _
ByVal container As Object, _
ByVal layoutEventArgs As LayoutEventArgs) As Boolean

    Dim parent As Control = container

    ' Use DisplayRectangle so that parent.Padding is honored.
    Dim parentDisplayRectangle As Rectangle = parent.DisplayRectangle
    Dim nextControlLocation As Point = parentDisplayRectangle.Location

    Dim c As Control
    For Each c In parent.Controls

        ' Only apply layout to visible controls.
        If c.Visible <> True Then
            Continue For
        End If

        ' Respect the margin of the control:
        ' shift over the left and the top.
        nextControlLocation.Offset(c.Margin.Left, c.Margin.Top)

        ' Set the location of the control.
        c.Location = nextControlLocation

        ' Set the autosized controls to their 
        ' autosized heights.
        If c.AutoSize Then
            c.Size = c.GetPreferredSize(parentDisplayRectangle.Size)
        End If

        ' Move X back to the display rectangle origin.
        nextControlLocation.X = parentDisplayRectangle.X

        ' Increment Y by the height of the control 
        ' and the bottom margin.
        nextControlLocation.Y += c.Height + c.Margin.Bottom
    Next c

    ' Optional: Return whether or not the container's 
    ' parent should perform layout as a result of this 
    ' layout. Some layout engines return the value of 
    ' the container's AutoSize property.
    Return False

End Function

Observações

Este método é chamado quando o motor de layout pretende realizar uma operação de layout sobre o container parâmetro. Pode verificar o valor do AffectedProperty, , e AffectedControl as propriedades em layoutEventArgs para decidir se uma operação de AffectedComponentlayout é necessária.

Notas para Herdeiros

Substitua o Layout(Object, LayoutEventArgs) método para fornecer o seu comportamento de layout personalizado.

Ao apresentar o conteúdo do container parâmetro, certifique-se de verificar as Visible propriedades de cada controlo filho.

Retorne true se a lógica do motor de layout determinar que o layout deve ser realizado novamente pelo pai do contentor. Isto pode ocorrer, por exemplo, quando o motor de layout redimensiona os controlos filhos e determina que o contentor deve ser aumentado de tamanho para acomodar o novo layout.

Ver também

• LayoutEventArgs
• Como: Implementar um Motor de Layout Personalizado