LayoutEngine.Layout(Object, LayoutEventArgs) Metod

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

Parametrar

Returer

true om layouten ska utföras igen av överordnad i container, annars , false.

Undantag

Exempel

Följande kodexempel visar hur metoden används Layout för att implementera anpassat layoutbeteende. Det här kodexemplet är en del av ett större exempel för LayoutEngine klassen.

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

Kommentarer

Den här metoden anropas när layoutmotorn ska utföra en layoutåtgärd på parametern container . Du kan kontrollera värdet för AffectedPropertyegenskaperna , AffectedComponentoch AffectedControl på layoutEventArgs för att avgöra om en layoutåtgärd är nödvändig.

Anteckningar till arvingar

Åsidosätt Layout(Object, LayoutEventArgs) metoden för att ange ditt anpassade layoutbeteende.

När du lägger ut innehållet i parametern container måste du kontrollera egenskapen för varje underordnad Visible kontroll.

Returnera true om logiken för layoutmotorn avgör att layouten ska utföras igen av containerns överordnade. Detta kan till exempel inträffa när layoutmotorn ändrar storlek på underordnade kontroller och fastställer att containern måste ökas i storlek för att rymma den nya layouten.

Se även

• LayoutEventArgs
• Gör så här: Implementera en anpassad layoutmotor