java - The switch statent and return values - How to use a switch to determin JPanel drawn -


i have program has different jpanels written in different classes. print particular jpanel depending on button clicked user.

when program launched, has 3 buttons: "animals jbutton", "plants jbutton" , "refresh jbutton" in jframe "frame"; no jpanel.

if, example, user clicks on "animals jbutton", jpanel animals gets printed on jframe.

the "animalsjpanel" , "plantsjpanel" written in different classes. class, "pagereturner", has method determines gets printed via switch.

public class redirect {      string pageanimals = "pageanimals";     string pageplants = "pageplants";      string value;      public string pageredirect (string pageid) {         switch (pageid) {             case pageanimals:                 value = (animalsjpanel animalsjpanel = new animalsjpanel());             break;             case pageplants:                 value = (plantsjpanel plantsjpanel = new plantsjpanel());                 break;             case 2:                 value = null;                 break;         }         return null;      }  }

i "constant string expression required" , "incopatible types" errors in netbeans. might problem switch statement, , there better way go this, i.e, determining page print. i'd code , not use cardlayout. i'm new java , trying learn how objects classes.

is switch statement done. i'm teaching myself programming, , have no 1 consult. appreaciation in advance advice

declare variable final used in switch case.

   final string pageanimals = "pageanimals";    final string pageplants = "pageplants";

since case labels should compile time constants in switch.


-

Comments

Post a Comment

Popular posts from this blog

scala - 'wrong top statement declaration' when using slick in IntelliJ -

Image
i'm porting project scala 2.9 2.10, therefore have use slick instead of scalaquery. i'm using slick 2.1.0 since supports ms access. according this tutorial , upgrade guide changed robs object class , added val robs : why error message wrong top statement declaration , how rid of it? edit: i'm new scala... according this question seems can't put val outside of methods or classes, right? code above directly in packge. right approach slick then? should move code in class or trait? according this changed val robs = tablequery[robs] to object robs extends tablequery(new robs(_)) {} . no warnings or errors anymore. :)
Read more

c# - DevExpress.Wpf.Grid.InfiniteGridSizeException was unhandled -

Image
when using devexpress, see error: devexpress.wpf.grid.infinitegridsizeexception unhandled message="by default, infinite grid height not allowed since grid rows rendered , hence grid work slowly. fix issue, should place grid container give finite height grid, or should manually specify grid's height or maxheight. note can avoid exception setting gridcontrol.allowinfinitegridsize static property true, in case grid run slowly." the problem dxgrid has infinite height. to fix, set height non-infinite. snoop absolutely invaluable this: if "height" xaml element infinite (i.e. 0 or nan ), can set using one of following: option 1: height="{binding path=actualheight, relativesource={relativesource mode=findancestor, ancestortype=uielement}}" option 2: verticalalignment="stretch" option 3: height="auto" hint: use verticalalignment="stretch" if child of grid <rowdefinition height=
Read more

PySide and Qt Properties: Connecting signals from Python to QML -

i trying run simple pyside appliccation design made in qml. call function in qml python in separated thread. i have following qml view: import qt 4.7 rectangle { visible: true width: 100; height: 100 color: "lightgrey" text { id: datestr objectname: "datestr" x: 10 y: 10 text: "init text" font.pixelsize: 12 function updatedata(text) { datestr.text = qstr(text) console.log("you said: " + text) } } } here application: some imports.... #!/usr/bin/python import sys import time pyside import qtdeclarative, qtcore pyside.qtgui import qapplication pyside.qtdeclarative import qdeclarativeview the qthread worker.... #worker thread class worker(qtcore.qthread): updateprogress = qtcore.signal(int) def __init__(self, child): qtcore.qthread.__init__(self) self.child = child def run(self):
Read more