java - Background color does not change in bluej -


i have written code has label , button in frame. have changed background never changes. 

    import javax.swing.*;     import java.awt.*;      import javax.swing.border.*;     public class frames      {     jframe main_menu=new jframe("main menu");jframe circumference=new jframe("circumference");     jframe area=new jframe("area");jframe perimeter=new jframe("perimeter");jframe sets=new   jframe("sets");     jframe fundamental_oprations=new jframe("fundamental oprations");jframe power_and_roots=new jframe("power_and_roots");     void main_menu()     {         jpanel contentpane = (jpanel) main_menu.getcontentpane();         contentpane.setlayout(new borderlayout(10,10));         contentpane.setborder(new emptyborder(300, 150, 300, 150));         contentpane.setlayout(new gridlayout(4, 4));         jpanel buttonpanel = new jpanel(new gridlayout(8,8));         contentpane.add(labels.main_menu,borderlayout.north);         contentpane.add(buttons.sets,borderlayout.south);         main_menu.setbackground(color.yellow);         main_menu.pack();         main_menu.setvisible(true);       }       }

you should setting background color of content pane via getcontentpane().setbackground(color.yellow):

import java.awt.color; import java.awt.dimension; import java.awt.eventqueue;  import javax.swing.jframe;  public class frames extends jframe {     private static final long serialversionuid = 1l;      public static void main(string[] args) {         eventqueue.invokelater(new runnable() {             public void run() {                 try {                     new frames();                 } catch (exception e) {                     e.printstacktrace();                 }             }         });     }      public frames() {         setsize(new dimension(100, 100));         settitle("main menu");         getcontentpane().setbackground(color.yellow);         setvisible(true);     }  }

also, consider using variable naming conventions; instance, main_menu should named mainmenu.


Comments

Post a Comment

Popular posts from this blog

commonjs - How to write a typescript definition file for a node module that exports a function? -

consider, toml node module can use: // toml.d.ts declare module toml { export function parse(value:string):any; } declare module "toml" { export = toml; } then: /// <reference path="../../../../../defs/toml/toml.d.ts"/> import toml = require('toml'); toml.parse(...); however, node module export single function, such 'glob' ( https://github.com/isaacs/node-glob ). the node usage of module be: var glob = require("glob") glob("*.js", {}, callback(err, files) { ... }); you'd naively expect this: // glob.d.ts declare function globs(paths:string, options:any, callback:{(err:any, files:string[]):void; ...but because typescripts 'import' semantics bit strange, seems can use 'import .. = require()' statement alias modules . trying call: /// <reference path="../../../../../defs/glob/glob.d.ts"/> import blog = require('glob'); results in: error ts2072: mod...
Read more

openid - Okta: Failed to get authorization code through API call -

i'm integrating okta own idp server using okta's api. i'm implementing authorization code flow following steps below: in own server, use /api/v1/authn endpoint sessiontoken. use sessiontoken obtain authorization calling endpoint: /oauth2/v1/authorize?client_id=" + clientid + "&sessiontoken=" + sessiontoken + "&response_type=code&response_mode=query&scope=openid&redirect_uri=" + redirecturl + "&state=evanyang&nonce=" it's supposed return response status code 302 , location header containing redirect url code value. however, keep getting response status code 200 , without location header, html body saying "you using unsupported browser." , "javascript disabled on browser." according api documentation: http://developer.okta.com/docs/api/resources/oidc.html#authentication-request , sessiontoken parameter sufficient this: an okta one-time sessiontoken. allows api-based ...
Read more

ios - Change Storyboard View using Seague -

i have following code checks connection server, , depending on want change views if no connection found. nsstring *connect = [nsstring stringwithcontentsofurl:[nsurl urlwithstring:@"http://myserver.com"] encoding:nsutf8stringencoding error:nil]; if (connect == null) { [self performseguewithidentifier:@"network_failure" sender:self]; } else { // other code here } my problem not change views. have added storyboard segue between 2 views identifier of network_failure . not have navigation controller or that, problem? thanks help! no not problem. first of all, in objectivec exists nil object oriented null . must use that. so: if(connect == nil) or better: if(!connect) so due fact nil not same of null , probably code does't enter in if scope . you have been able discover breakpoint. anyway: be sure set trigger segue (line) 2 view controller , , name network_failure (that not best name. should instead view1toview2 ) as, m...
Read more