FrameworkElement.Height Property

Definition

Namespace:

System.Windows

Assembly:

PresentationFramework.dll

Gets or sets the suggested height of the element.

public:
 property double Height { double get(); void set(double value); };

[System.ComponentModel.TypeConverter(typeof(System.Windows.LengthConverter))]
[System.Windows.Localizability(System.Windows.LocalizationCategory.None, Readability=System.Windows.Readability.Unreadable)]
public double Height { get; set; }

[<System.ComponentModel.TypeConverter(typeof(System.Windows.LengthConverter))>]
[<System.Windows.Localizability(System.Windows.LocalizationCategory.None, Readability=System.Windows.Readability.Unreadable)>]
member this.Height : double with get, set

Public Property Height As Double

Property Value

Double

The height of the element, in device-independent units (1/96th inch per unit). The default value is NaN. This value must be equal to or greater than 0.0.

Attributes

TypeConverterAttribute LocalizabilityAttribute

Remarks

Height is one of three writable properties on FrameworkElement that specify height information. The other two are MinHeight and MaxHeight. If there is a conflict between these values, the order of application for actual height determination is that first MinHeight must be honored, then MaxHeight, and finally, if it is within bounds, Height.

If this element is a child element within some other element, then setting this property to a value is really only a suggested value. The layout system as well as the particular layout logic of the parent element will use the value as a nonbinding input during the layout process. In practical terms, a FrameworkElement is almost always the child element of something else; even when you set the Height on Window. (For Window, that value is used when the underlying application model establishes the basic rendering assumptions that create the Hwnd that hosts the application.)

In addition to acceptable Double values, this property can also be Double.NaN. This is how you specify auto sizing behavior in code. In XAML you set the value to the string "Auto" (case insensitive) to enable the auto sizing behavior. Auto sizing behavior implies that the element will fill the height available to it. Note however that specific controls frequently supply default values through their default theme styles that will disable the auto sizing behavior unless it is specifically re-enabled.

The return value of this property is always the same as any value that was set to it. In contrast, the value of the ActualHeight may vary. This can happen either statically because the layout rejected the suggested size for some reason, or momentarily. The layout system itself works asynchronously relative to the property system's set of Height and may not have processed that particular sizing property change yet.

The value restrictions on the Double value are enforced by a ValidateValueCallback mechanism. If you attempt to set an invalid value, a run-time exception is thrown.

In addition to the validation check, there is a nondeterministic upper value bound for Height that is enforced by the layout system (this is a very large number, larger than Single.MaxValue but smaller than Double.MaxValue). If you exceed this bound, the element will not render, and no exception is thrown. Do not set Height to a value that is significantly larger than the maximum size of any possible visual display, or you may exceed this nondeterministic upper bound.

XAML Attribute Usage

<object Height="double"/>  

-or-

<object Height="qualifiedDouble"/>  

-or-

<object Height="Auto"/>  

XAML Values

double
Double

String representation of a Double value equal to or greater than 0.0. See Remarks for upper bound information. This value is interpreted as a device-independent unit (1/96th inch) measurement. Strings need not explicitly include decimal points. For instance a value of 1 is acceptable.

qualifiedDouble
A double value as described above, followed by one of the following unit declaration strings: px, in, cm, pt.

px (default) is device-independent units (1/96th inch per unit)

in is inches; 1in==96px

cm is centimeters; 1cm==(96/2.54) px

pt is points; 1pt==(96/72) px

Auto
Enables autosizing behavior. See Remarks.

Dependency Property Information

Identifier field	HeightProperty
Metadata properties set to true	AffectsMeasure

See also

• ActualHeight