Measure Control with double.PositiveInfinity WPF -

Measure Control with double.PositiveInfinity WPF -

i working on custom command has custom panel , within custom panel have little , simple measureoverride method passes size of double.positiveinfinity children measureoverride method. custom panel should take care of layout , should create children bigger or smaller depending on window size.

if have dealt controls should know how wpf layout scheme works , every kid calls measureoverride calls measureoverride of childs children , on.

now problem when resize window, custom panel receive flag measure 1 time again hence measureoverride called 1 time again time while passing double.positiveinfitinty size children, children measureoverride doesn't called @ (but method should called according definition of wpf layout system). why so? thought when phone call measureoverride on parent children forced measure.

obviously wrong explain me how control/child know when measure again?

by way passing size of double.positiveinfinity children tell them take much space needed.

code:

protected override size measureoverride(size availablesize) { double x; double y; var children = this.internalchildren; (int = 0; < children.count; i++) { uielement kid = children[i]; child.measure(new size(double.positiveinfinity, double.positiveinfinity); y += child.desiredsize.height; x = math.max(x, child.desiredsize.width); } homecoming new size(x, y); }

code simple. dont why children doesnt measured again. , sorry if have misspelled in code.

your children won't measured 1 time again because don't have to: since maintain passing same size, wpf knows there no reason measure 1 time again since resulting desiredsize same.

that beingness said, desiredsize updated measure size kid considers appropriate. should take business relationship when overriding arrangeoverride, have no obligation to: arrange children way like, fact measureoverride called or not children should irrelevant.

wpf wpf-controls measureoverride