ToolStripItem.Placement Proprietà

Definizione

Spazio dei nomi:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Ottiene il layout corrente dell'elemento.

public:
 property System::Windows::Forms::ToolStripItemPlacement Placement { System::Windows::Forms::ToolStripItemPlacement get(); };

[System.ComponentModel.Browsable(false)]
public System.Windows.Forms.ToolStripItemPlacement Placement { get; }

[<System.ComponentModel.Browsable(false)>]
member this.Placement : System.Windows.Forms.ToolStripItemPlacement

Public ReadOnly Property Placement As ToolStripItemPlacement

Valore della proprietà

ToolStripItemPlacement

Uno dei valori di ToolStripItemPlacement.

Attributi

BrowsableAttribute

Esempio

Nell'esempio di codice seguente viene illustrato come usare la proprietà per il Placement rendering personalizzato. Questo esempio di codice fa parte di un esempio più ampio fornito per la ToolStripItem classe .

// This method defines the behavior for rendering the
// background of a ToolStripItem. If the item is a
// RolloverItem, it paints the item's BackgroundImage 
// centered in the client area. If the mouse is in the 
// item's client area, a border is drawn around it.
// If the item is on a drop-down or if it is on the
// overflow, a gradient is painted in the background.
protected override void OnRenderItemBackground(
    ToolStripItemRenderEventArgs e)
{
    base.OnRenderItemBackground(e);

    RolloverItem item = e.Item as RolloverItem;

    // If the ToolSTripItem is of type RolloverItem, 
    // perform custom rendering for the background.
    if (item != null)
    {
        if (item.Placement == ToolStripItemPlacement.Overflow ||
            item.IsOnDropDown)
        {
            using (LinearGradientBrush b = new LinearGradientBrush(
                item.ContentRectangle,
                Color.Salmon,
                Color.DarkRed,
                0f,
                false))
            {
                e.Graphics.FillRectangle(b, item.ContentRectangle);
            }
        }

        // The RolloverItem control only supports 
        // the ImageLayout.Center setting for the
        // BackgroundImage property.
        if (item.BackgroundImageLayout == ImageLayout.Center)
        {
            // Get references to the item's ContentRectangle
            // and BackgroundImage, for convenience.
            Rectangle cr = item.ContentRectangle;
            Image bgi = item.BackgroundImage;

            // Compute the center of the item's ContentRectangle.
            int centerX = (cr.Width - bgi.Width) / 2;
            int centerY = (cr.Height - bgi.Height) / 2;

            // If the item is selected, draw the background
            // image as usual. Otherwise, draw it as disabled.
            if (item.Selected)
            {
                e.Graphics.DrawImage(bgi, centerX, centerY);
            }
            else
            {
                ControlPaint.DrawImageDisabled(
                        e.Graphics,
                        bgi,
                        centerX,
                        centerY,
                        item.BackColor);
            }
        }

        // If the item is in the rollover state, 
        // draw a border around it.
        if (item.Rollover)
        {
            ControlPaint.DrawFocusRectangle(
                e.Graphics,
                item.ContentRectangle);
        }
    }
}

' This method defines the behavior for rendering the
' background of a ToolStripItem. If the item is a
' RolloverItem, it paints the item's BackgroundImage 
' centered in the client area. If the mouse is in the 
' item's client area, a border is drawn around it.
' If the item is on a drop-down or if it is on the
' overflow, a gradient is painted in the background.
Protected Overrides Sub OnRenderItemBackground(ByVal e As ToolStripItemRenderEventArgs)
    MyBase.OnRenderItemBackground(e)

    Dim item As RolloverItem = CType(e.Item, RolloverItem)

    ' If the ToolSTripItem is of type RolloverItem, 
    ' perform custom rendering for the background.
    If (item IsNot Nothing) Then
        If item.Placement = ToolStripItemPlacement.Overflow OrElse item.IsOnDropDown Then
            Dim b As New LinearGradientBrush(item.ContentRectangle, Color.Salmon, Color.DarkRed, 0.0F, False)
            Try
                e.Graphics.FillRectangle(b, item.ContentRectangle)
            Finally
                b.Dispose()
            End Try
        End If

        ' The RolloverItem control only supports 
        ' the ImageLayout.Center setting for the
        ' BackgroundImage property.
        If item.BackgroundImageLayout = ImageLayout.Center Then
            ' Get references to the item's ContentRectangle
            ' and BackgroundImage, for convenience.
            Dim cr As Rectangle = item.ContentRectangle
            Dim bgi As Image = item.BackgroundImage

            ' Compute the center of the item's ContentRectangle.
            Dim centerX As Integer = CInt((cr.Width - bgi.Width) / 2)
            Dim centerY As Integer = CInt((cr.Height - bgi.Height) / 2)

            ' If the item is selected, draw the background
            ' image as usual. Otherwise, draw it as disabled.
            If item.Selected Then
                e.Graphics.DrawImage(bgi, centerX, centerY)
            Else
                ControlPaint.DrawImageDisabled(e.Graphics, bgi, centerX, centerY, item.BackColor)
            End If
        End If

        ' If the item is in the rollover state, 
        ' draw a border around it.
        If item.Rollover Then
            ControlPaint.DrawFocusRectangle(e.Graphics, item.ContentRectangle)
        End If
    End If
End Sub

Commenti

Esaminare la Placement proprietà in un LayoutCompleted evento per determinare se un elemento è stato inserito nell'oggetto principale ToolStrip, l'overflow ToolStripo se non è attualmente visualizzato. I motivi tipici per cui non viene visualizzato un elemento sono che l'elemento non rientra nell'oggetto principale ToolStrip e la relativa Overflow proprietà è stata impostata su Never.