[This documentation is preliminary and is subject to change.]

Updates the DesiredSize of a UIElement. Typically, objects that implement custom layout for their layout children call this method from their own MeasureOverride implementations to form a recursive layout update.

Syntax

public void Measure(
  Size availableSize
)

Parameters

availableSize

Type: Size

The available space that a parent can allocate to a child object. A child object can request a larger space than what is available; the provided size might be accommodated if scrolling or other resize behavior is possible in that particular container.

Remarks

The Measure call potentially reaches a MeasureOverride implementation of that specific class. Otherwise, most FrameworkElement classes have an implicit default layout behavior for Measure.

Examples

This example implements MeasureOverride to customize the "Measure" pass logic for a custom panel implementation. Note in particular these aspects of the code:

• Iterates over children.

• For each child, calls Measure, using a Size that makes sense based on how the panel logic treats the number of children and its own known size limit.

• Returns its size (in this case, this simple panel returns a fixed size rather than a size calculated on accumulating the measurements).

// First measure all children and return available size of panel
protected override Size MeasureOverride(Size availableSize)
{

    // Measure first 9 children giving them space up to 100x100, remaining children get 0x0 
    int i = 0;
    foreach (FrameworkElement child in Children)
    {
        if (i < 9)
        {
            child.Measure(new Size(100, 100));
        }
        else
        {
            child.Measure(new Size(0, 0));
        }

        i++;
    }


    // return the size available to the whole panel, which is 300x300
    return new Size(300, 300);
}

Requirements

See also

UIElement

Build date: 5/22/2012