FrameworkElement.ActualWidth プロパティ

定義

この要素の描画時の幅を取得します。Gets the rendered width of this element.

public:
 property double ActualWidth { double get(); };
public double ActualWidth { get; }
member this.ActualWidth : double
Public ReadOnly Property ActualWidth As Double

プロパティ値

Double

要素の幅を、デバイスに依存しない単位 (1/1/96 インチ/ユニット) の値として指定します。The element's width, as a value in device-independent units (1/96th inch per unit). 既定値は 0 (ゼロ) です。The default value is 0 (zero).

次の例では、さまざまな幅のプロパティを表示します。The following example displays various width properties.

private void changeWidth(object sender, SelectionChangedEventArgs args)
{
    ListBoxItem li = ((sender as ListBox).SelectedItem as ListBoxItem);
    Double sz1 = Double.Parse(li.Content.ToString());
    rect1.Width = sz1;
    rect1.UpdateLayout();
    txt1.Text = "ActualWidth is set to " + rect1.ActualWidth;
    txt2.Text = "Width is set to " + rect1.Width;
    txt3.Text = "MinWidth is set to " + rect1.MinWidth;
    txt4.Text = "MaxWidth is set to " + rect1.MaxWidth;
}
private void changeMinWidth(object sender, SelectionChangedEventArgs args)
{
    ListBoxItem li = ((sender as ListBox).SelectedItem as ListBoxItem);
    Double sz1 = Double.Parse(li.Content.ToString());
    rect1.MinWidth = sz1;
    rect1.UpdateLayout();
    txt1.Text = "ActualWidth is set to " + rect1.ActualWidth;
    txt2.Text = "Width is set to " + rect1.Width;
    txt3.Text = "MinWidth is set to " + rect1.MinWidth;
    txt4.Text = "MaxWidth is set to " + rect1.MaxWidth;
}
private void changeMaxWidth(object sender, SelectionChangedEventArgs args)
{
    ListBoxItem li = ((sender as ListBox).SelectedItem as ListBoxItem);
    Double sz1 = Double.Parse(li.Content.ToString());
    rect1.MaxWidth = sz1;
    rect1.UpdateLayout();
    txt1.Text = "ActualWidth is set to " + rect1.ActualWidth;
    txt2.Text = "Width is set to " + rect1.Width;
    txt3.Text = "MinWidth is set to " + rect1.MinWidth;
    txt4.Text = "MaxWidth is set to " + rect1.MaxWidth;
}
Private Sub changeWidth(ByVal sender As Object, ByVal args As SelectionChangedEventArgs)
    Dim li As ListBoxItem = CType(CType(sender, ListBox).SelectedItem, ListBoxItem)
    Dim sz1 As Double = Double.Parse(li.Content.ToString())
    rect1.Width = sz1
    rect1.UpdateLayout()
    txt1.Text = "ActualWidth is set to " + rect1.ActualWidth.ToString
    txt2.Text = "Width is set to " + rect1.Width.ToString
    txt3.Text = "MinWidth is set to " + rect1.MinWidth.ToString
    txt4.Text = "MaxWidth is set to " + rect1.MaxWidth.ToString
End Sub
Private Sub changeMinWidth(ByVal sender As Object, ByVal args As SelectionChangedEventArgs)

    Dim li As ListBoxItem = CType(CType(sender, ListBox).SelectedItem, ListBoxItem)
    Dim sz1 As Double = Double.Parse(li.Content.ToString())
    rect1.MinWidth = sz1
    rect1.UpdateLayout()
    txt1.Text = "ActualWidth is set to " + rect1.ActualWidth.ToString
    txt2.Text = "Width is set to " + rect1.Width.ToString
    txt3.Text = "MinWidth is set to " + rect1.MinWidth.ToString
    txt4.Text = "MaxWidth is set to " + rect1.MaxWidth.ToString
End Sub
Private Sub changeMaxWidth(ByVal sender As Object, ByVal args As SelectionChangedEventArgs)

    Dim li As ListBoxItem = CType(CType(sender, ListBox).SelectedItem, ListBoxItem)
    Dim sz1 As Double = Double.Parse(li.Content.ToString())
    rect1.MaxWidth = sz1
    rect1.UpdateLayout()
    txt1.Text = "ActualWidth is set to " + rect1.ActualWidth.ToString
    txt2.Text = "Width is set to " + rect1.Width.ToString
    txt3.Text = "MinWidth is set to " + rect1.MinWidth.ToString
    txt4.Text = "MaxWidth is set to " + rect1.MaxWidth.ToString
End Sub

注釈

このプロパティは、他の幅入力とレイアウトシステムに基づく計算値です。This property is a calculated value based on other width inputs, and the layout system. 値は、実際のレンダリングパスに基づいてレイアウトシステム自体によって設定されます。したがって、入力の変更の基礎となるなどのプロパティの設定値よりも少し遅れが生じることがあり Width ます。The value is set by the layout system itself, based on an actual rendering pass, and may therefore lag slightly behind the set value of properties such as Width that are the basis of the input change.

ActualWidth は計算された値であるため、レイアウト システムによるさまざまな操作の結果として、その値に対して複数の変更や増分変更が報告される可能性があることにご注意ください。Because ActualWidth is a calculated value, you should be aware that there could be multiple or incremental reported changes to it as a result of various operations by the layout system. レイアウト システムが、子要素に必要な測定スペース、親要素による制約などを計算している場合があります。The layout system may be calculating required measure space for child elements, constraints by the parent element, and so on.

このプロパティを XAML から設定することはできませんが、スタイルの値に基づいてを作成することはでき Trigger ます。Although you cannot set this property from XAML, you can base a Trigger upon its value in a style.

依存プロパティ情報Dependency Property Information

識別子フィールドIdentifier field ActualWidthProperty
メタデータプロパティがに設定される trueMetadata properties set to true なしNone

適用対象