java - How to add background image to jframe confused -

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• background image in jframe 3 answers

how can can add background image jframe , should u add code?

import java.awt.*; import java.awt.event.*; import javax.swing.imageicon.*; import javax.swing.*; //import java swing use jframe etc  public class mathquiz extends jframe implements actionlistener {  jcheckbox answer1 = new jcheckbox(); //checkbozx answer 1 jcheckbox answer2 = new jcheckbox(); //checkbozx answer 2 jcheckbox answer3 = new jcheckbox(); //checkbozx answer 3 jtextarea textarea = new jtextarea();//text area question jbutton exit = new jbutton(); // button exit quiz jbutton calculator = new jbutton(); // button open calculator jlabel image = new jlabel(); //adds background image  // names associated numbers. int answer; int questionnumber;   /**    * bit of code starts process of showing window. **/ public mathquiz() {     // drop down code labeled 'initcomponents' below.      try {         initcomponents();     } catch (exception e) {}  }   /**  * bit of code first bit that's run. **/ static public void main(string[] args) {     mathquiz frame = new mathquiz();      // following code puts window on screen.      frame.setvisible(true); //allows jframe visible     frame.showquestion(1);//shows first question     frame.setsize(370, 350);//sets size of frame  }  /**  * bit of code sets how window looks. **/ public void initcomponents() throws exception { 

edits checkboxes answers

    answer1.setsize(new dimension(80, 20)); //set size of answer 1 checkbox     answer1.setvisible(true); //sets visible answer 1 checkbox     answer1.setmaximumsize(new dimension(80, 20));      answer1.setminimumsize(new dimension(80, 20));      answer1.setlocation(new point(10, 180)); //set location answer 1 checkbox       answer2.setsize(new dimension(80, 20)); //set size of answer 2 checkbox     answer2.setvisible(true);//sets visible answer 2 checkbox     answer2.setmaximumsize(new dimension(80, 20));     answer2.setminimumsize(new dimension(80, 20));     answer2.setlocation(new point(10, 210)); //set location answer 2 checkbox      answer3.setsize(new dimension(80, 20)); //set size of answer 3 checkbox     answer3.setvisible(true);//sets visible answer 3 checkbox     answer3.setmaximumsize(new dimension(80, 20));     answer3.setminimumsize(new dimension(80, 20));     answer3.setlocation(new point(10, 240)); //set location answer 3 checkbox 

code edit text area on jframe

    textarea.setsize(new dimension(340, 80)); //set size of text ares     textarea.setlinewrap(true);      textarea.setvisible(true); //sets visible text area     textarea.setmaximumsize(new dimension(400, 140)); //set maximum size of text area     textarea.setminimumsize(new dimension(400, 140)); //set minimum size of text area     textarea.setlocation(new point(10, 20)); //set location of text area     textarea.seteditable(false); 

code edit exit button on jframe

    exit.setsize(new dimension(104, 40)); //set size of button     exit.setvisible(true); //sets visible button     exit.setlocation(new point(230, 180)); //set location of button     exit.settext("exit"); 

code edit exit button on jframe

    calculator.setsize(new dimension(104, 40)); //set size of button     calculator.setvisible(true); //sets visible button     calculator.setlocation(new point(230, 230)); //set location of button     calculator.settext("calculator");      image.seticon(new imageicon("maths"));     image.setvisible(true); 

this sets size of window , adds swing utilities

    setsize(new dimension(430, 292));     setresizable(false);     getcontentpane().setlayout(null);     settitle("multiple choice math quiz!");     setlocation(new point(200, 200));     getcontentpane().add(answer1);     getcontentpane().add(answer2);     getcontentpane().add(answer3);     getcontentpane().add(textarea);     getcontentpane().add(exit);     getcontentpane().add(calculator); 

you adding image jlabel add in turn jframe.

as highlighted in comments, problem lies in null layout use.

try layout manager.