Flex UI Components disappear - actionscript-3

Question

I've implemented a method to change display size.
When I click on maximize, I reposition some buttons in a viewstack.
Problem is when I restore view the buttons disappear.
Can someone help me?
{
nativeWindow.addEventListener(NativeWindowBoundsEvent.RESIZING, onAppResize);
nativeWindow.addEventListener(NativeWindowBoundsEvent.RESIZE, onAppResize);
nativeWindow.addEventListener(NativeWindowDisplayStateEvent.DISPLAY_STATE_CHANGING,onAppMaximized);
var screenBounds:Rectangle = Screen.mainScreen.bounds;
nativeWindow.x = 10;
nativeWindow.y = 10;
}
private function onAppMaximized(e:NativeWindowDisplayStateEvent):void
{
if(String(e.afterDisplayState) == "maximized" && DisplayMaximized == false)
{
e.preventDefault();
nativeWindow.x = 10;
nativeWindow.y = 10;
AppImageWidth = 1280;
AppImageHeight = 900;
nativeWindow.width = 1280;
nativeWindow.height = 900;
viewstack.createComponentsFromDescriptors(true);
viewstackBuchungen.width = 1206;
viewstackBuchungen.height = 600;
Button.x = 1135;
Button.y = 608;
Button2.x = 1135;
Button2.y = 608;
DisplayMaximized = true;
}
else if(String(e.afterDisplayState) == "maximized" && DisplayMaximized == true)
{
e.preventDefault();
AppImageWidth = 1024;
AppImageHeight = 600;
nativeWindow.width = 1024;
nativeWindow.height = 600;
viewstackBuchungen.width = 950;
viewstackBuchungen.height = 313;
Button.x = 879;
Button.y = 321;
Button2.x = 879;
Button2.y = 321;
DisplayMaximized = false;
}
}

Answer 1

thanks for your answer.
I tried moving them with .move(x,y).
Nothing changed...
The buttons are on same position, because they are in different navigator content.
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx" creationComplete="init();" width="1024" height="600">
private function init():void
{
nativeWindow.addEventListener(NativeWindowBoundsEvent.RESIZING, onAppResize);
nativeWindow.addEventListener(NativeWindowBoundsEvent.RESIZE, onAppResize);
nativeWindow.addEventListener(NativeWindowDisplayStateEvent.DISPLAY_STATE_CHANGING,onAppMaximized);
nativeWindow.x = 10;
nativeWindow.y = 10;
}
private function onAppResize(e:NativeWindowBoundsEvent):void
{
e.preventDefault();
}
private function onAppMaximized(e:NativeWindowDisplayStateEvent):void
{
if(String(e.afterDisplayState) == "maximized" && DisplayMaximized == false)
{
e.preventDefault();
nativeWindow.x = 10;
nativeWindow.y = 10;
nativeWindow.width = 1280;
nativeWindow.height = 900;
viewstack1.createComponentsFromDescriptors(true);
viewstack1.width = 1206;
viewstack1.height = 600;
button1.move(1135,608);
button2.move(1135,608);
DD1.move(1082,608);
DisplayMaximized = true;
}
else if(String(e.afterDisplayState) == "maximized" && DisplayMaximized == true)
{
e.preventDefault();
nativeWindow.width = 1024;
nativeWindow.height = 600;
viewstack1.width = 950;
viewstack1.height = 313;
button1.move(879,321);
button2.move(879,321);
DD1.move(826,321);
DisplayMaximized = false;
}
}
]]>
</fx:Script>
<fx:Declarations>
<!-- Platzieren Sie nichtvisuelle Elemente (z. B. Dienste, Wertobjekte) hier -->
</fx:Declarations>
<s:Group x="16" y="113" width="1254" height="463">
<mx:ViewStack id="viewstack1" x="0" y="24" width="950" height="313" selectedIndex="0" creationPolicy="all">
<s:NavigatorContent width="100%" height="100%" label="Nav1" id="nav1" creationPolicy="all">
<mx:AdvancedDataGrid id="grid1" x="0" y="0" width="100%" height="100%"
designViewDataType="flat"
editable="true" horizontalScrollPolicy="off"
sortableColumns="false" resizableColumns="false" draggableColumns="false">
<mx:columns>
<mx:AdvancedDataGridColumn dataField="test1" headerText="test1" width="35"/>
</mx:columns>
</mx:AdvancedDataGrid>
<s:Button x="879" y="321" label="Button1" id="button1"/>
</s:NavigatorContent>
<s:NavigatorContent width="100%" height="100%" label="Nav2" id="nav2" creationPolicy="all">
<mx:AdvancedDataGrid id="grid2" x="0" y="0" width="100%" height="100%"
designViewDataType="flat"
editable="true" horizontalScrollPolicy="off"
sortableColumns="false" resizableColumns="false" draggableColumns="false">
<mx:columns>
<mx:AdvancedDataGridColumn dataField="test2" headerText="test2" width="35"/>
</mx:columns>
</mx:AdvancedDataGrid>
<s:Button x="879" y="321" label="Button2" id="button2" />
</s:NavigatorContent>
<s:NavigatorContent width="100%" height="100%" label="Nav3" id="nav3" creationPolicy="all">
<mx:AdvancedDataGrid id="grid3" x="0" y="0" width="100%" height="100%"
designViewDataType="flat"
editable="true" horizontalScrollPolicy="off"
sortableColumns="false" resizableColumns="false" draggableColumns="false">
<mx:columns>
<mx:AdvancedDataGridColumn dataField="test3" headerText="test3" width="35"/>
</mx:columns>
</mx:AdvancedDataGrid>
<s:DropDownList x="826" id="DD1" y="321" width="125" prompt="DD1" alpha="1"/>
</s:NavigatorContent>
</mx:ViewStack>
<s:TabBar x="0" y="0" dataProvider="{viewstack1}" />
</s:Group>