FrameworkElement.ActualHeight 屬性

定義

命名空間:

System.Windows

組件:

PresentationFramework.dll

取得呈現此項目的高度。

C#

public double ActualHeight { get; }

屬性值

Double

元素的高度，以裝置獨立單位 (每單位 1/96 英吋的值) 。 預設值是 0 (零)。

範例

下列範例會顯示各種高度屬性。

C#

private void changeHeight(object sender, SelectionChangedEventArgs args)
{
    ListBoxItem li = ((sender as ListBox).SelectedItem as ListBoxItem);
    Double sz1 = Double.Parse(li.Content.ToString());
    rect1.Height = sz1;
    rect1.UpdateLayout();
    txt1.Text= "ActualHeight is set to " + rect1.ActualHeight;
    txt2.Text= "Height is set to " + rect1.Height;
    txt3.Text= "MinHeight is set to " + rect1.MinHeight;
    txt4.Text= "MaxHeight is set to " + rect1.MaxHeight;
}
private void changeMinHeight(object sender, SelectionChangedEventArgs args)
{
    ListBoxItem li = ((sender as ListBox).SelectedItem as ListBoxItem);
    Double sz1 = Double.Parse(li.Content.ToString());
    rect1.MinHeight = sz1;
    rect1.UpdateLayout();
    txt1.Text= "ActualHeight is set to " + rect1.ActualHeight;
    txt2.Text= "Height is set to " + rect1.Height;
    txt3.Text= "MinHeight is set to " + rect1.MinHeight;
    txt4.Text= "MaxHeight is set to " + rect1.MaxHeight;
}
private void changeMaxHeight(object sender, SelectionChangedEventArgs args)
{
    ListBoxItem li = ((sender as ListBox).SelectedItem as ListBoxItem);
    Double sz1 = Double.Parse(li.Content.ToString());
    rect1.MaxHeight = sz1;
    rect1.UpdateLayout();
    txt1.Text= "ActualHeight is set to " + rect1.ActualHeight;
    txt2.Text= "Height is set to " + rect1.Height;
    txt3.Text= "MinHeight is set to " + rect1.MinHeight;
    txt4.Text= "MaxHeight is set to " + rect1.MaxHeight;
}

備註

此屬性是根據其他高度輸入和版面配置系統的計算值。 值是由版面配置系統本身根據實際轉譯階段來設定，因此可能會稍微落後屬性的設定值，例如 Height 輸入變更的基礎。

由於 ActualHeight 是計算值，因此您應該注意，配置系統可能會因為各種作業而產生多個或累加報告變更。 配置系統可能會計算子項目所需的測量空間、父項目的條件約束，依此類推。

雖然您無法從 XAML 設定這個屬性，但您可以使用 Trigger 樣式根據其值。

相依性屬性資訊

識別碼欄位	ActualHeightProperty
設定為 的中繼資料屬性 true	無

適用於