大家帮帮我，我的程序为什么不出界面（编译通过，执行时一闪即逝）

Question

else{
                             FLAG2++;
                             OP3+=9/Math.pow(10,(double)FLAG2);
                             op=new Double(OP1+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
                   else{
                         if(FLAG2<0){
                             OP2=10*OP2+9;
                             op=new Double(OP2);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=9/Math.pow(10,(double)FLAG2);
                             op=new Double(OP2+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
             } 
             if(e.getActionCommand()=="button4") { 
                   FLAG1=4; 
                   FLAG2=-1;
             }
             if(e.getActionCommand()=="button5") { 
                   if(FLAG1==0){
                         if(FLAG2<0){
                             OP1=10*OP1+4;
                             op=new Double(OP1);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=4/Math.pow(10,(double)FLAG2);
                             op=new Double(OP1+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
                   else{
                         if(FLAG2<0){
                             OP2=10*OP2+4;
                             op=new Double(OP2);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=4/Math.pow(10,(double)FLAG2);
                             op=new Double(OP2+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
             }               
             if(e.getActionCommand()=="button6") { 
                   if(FLAG1==0){
                         if(FLAG2<0){
                             OP1=10*OP1+5;
                             op=new Double(OP1);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=5/Math.pow(10,(double)FLAG2);
                             op=new Double(OP1+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
                   else{
                         if(FLAG2<0){
                             OP2=10*OP2+5;
                             op=new Double(OP2);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=5/Math.pow(10,(double)FLAG2);
                             op=new Double(OP2+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
             }   
             if(e.getActionCommand()=="button7") {
                   if(FLAG1==0){
                         if(FLAG2<0){
                             OP1=10*OP1+6;
                             op=new Double(OP1);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=6/Math.pow(10,(double)FLAG2);
                             op=new Double(OP1+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
                   else{
                         if(FLAG2<0){
                             OP2=10*OP2+6;
                             op=new Double(OP2);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=6/Math.pow(10,(double)FLAG2);
                             op=new Double(OP2+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
             }
             if(e.getActionCommand()=="button8") { 
                   FLAG1=8;
                   FLAG2=-1;
             }
             if(e.getActionCommand()=="button9") { 
                   if(FLAG1==0){
                         if(FLAG2<0){
                             OP1=10*OP1+1;
                              op=new Double(OP1);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=1/Math.pow(10,(double)FLAG2);
                             op=new Double(OP1+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
                   else{
                         if(FLAG2<0){
                             OP2=10*OP2+1;
                             op=new Double(OP2);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=1/Math.pow(10,(double)FLAG2);
                             op=new Double(OP2+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
             }
             if(e.getActionCommand()=="button10") { 
                   if(FLAG1==0){
                         if(FLAG2<0){
                             OP1=10*OP1+2;
                              op=new Double(OP1);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=2/Math.pow(10,(double)FLAG2);
                             op=new Double(OP1+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }

Answer 1

                   else{
                         if(FLAG2<0){
                             OP2=10*OP2+2;
                             op=new Double(OP2);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=2/Math.pow(10,(double)FLAG2);
                             op=new Double(OP2+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
             }
             if(e.getActionCommand()=="button11") { 
                   if(FLAG1==0){
                         if(FLAG2<0){
                             OP1=10*OP1+3;
                              op=new Double(OP1);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=3/Math.pow(10,(double)FLAG2);
                             op=new Double(OP1+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
                   else{
                         if(FLAG2<0){
                             OP2=10*OP2+3;
                             op=new Double(OP2);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=3/Math.pow(10,(double)FLAG2);
                             op=new Double(OP2+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
             }
             if(e.getActionCommand()=="button12") {
                   FLAG1=12;
                   FLAG2=-1;
             }
             if(e.getActionCommand()=="button13") { 
                   if(FLAG1==0){
                         if(FLAG2<0){
                             OP1=10*OP1+0;
                             op=new Double(OP1);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=0/Math.pow(10,(double)FLAG2);
                             op=new Double(OP1+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
                   else{
                         if(FLAG2<0){
                             OP2=10*OP2+0;
                             op=new Double(OP2);
                             result.setText(op.toString(op.doubleValue()));
                         }
                         else{
                             FLAG2++;
                             OP3+=0/Math.pow(10,(double)FLAG2);
                             op=new Double(OP2+OP3);
                             result.setText(op.toString(op.doubleValue()));
                         }
                   }
             }
             if(e.getActionCommand()=="button14") { 
                   if(FLAG1==0){
                         OP1=Math.PI;
                         op=new Double(OP1);
                         result.setText(op.toString(op.doubleValue()));
                   }
                   else{
                         OP2=Math.PI;
                         op=new Double(OP2);
                         result.setText(op.toString(op.doubleValue()));
                   }      
              }       
             if(e.getActionCommand()=="button15") {
                   OP4=Math.log(OP1);
                   op=new Double(OP4);
                   result.setText(op.toString(op.doubleValue()));
                   FLAG1=0;
                   FLAG2=-1;
             }
             if(e.getActionCommand()=="button16") {
                   FLAG1=16;
                   FLAG2=-1;
             }
             if(e.getActionCommand()=="button17") {
                   result.setText("                       ");
                   FLAG1=0;
                   FLAG2=-1;
             }
             if(e.getActionCommand()=="button18") {
                   if(FLAG1==0){
                         OP1=-1*OP1;
                         op=new Double(OP1);
                         result.setText(op.toString(op.doubleValue()));
                   }
                   else{
                         OP2=-1*OP2;
                         op=new Double(OP2);
                         result.setText(op.toString(op.doubleValue()));
                   }
             }
             if(e.getActionCommand()=="button19") {
                   FLAG2=0;
             }
             if(e.getActionCommand()=="button20") {
                   switch(FLAG1){
                         case 4:
                               OP4=OP1/OP2;
                               op=new Double(OP4);
                               result.setText(op.toString(op.doubleValue()));
                               FLAG1=0;
                               FLAG2=-1;break;
                         case 8:
                               OP4=OP1*OP2;
                               op=new Double(OP4);
                               result.setText(op.toString(op.doubleValue()));
                               FLAG1=0;
                               FLAG2=-1;break;
                         case 12:
                               OP4=OP1-OP2;
                               op=new Double(OP4);
                               result.setText(op.toString(op.doubleValue()));
                               FLAG1=0;
                               FLAG2=-1;break;
                         case 16:
                               OP4=OP1+OP2;
                               op=new Double(OP4);
                               result.setText(op.toString(op.doubleValue()));
                               FLAG1=0;
                               FLAG2=-1;break;
                    }
             }
        
   }
   public static void main(String[] args){
          /*counterFrame=new JFrame("Calculator");*/
          try {
           
                   UIManager.setLookAndFeel(
 UIManager.getCrossPlatformLookAndFeelClassName());
 
           } catch (Exception e) {} 
         Calculator calculator1=new Calculator();
         /* counterFrame.add(resultPanel);
        counterFrame.add(keyPanel);
        counterFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        counterFrame.pack();
        counterFrame.setVisible(true);*/
   }
}

Answer 2

构建器应为public Calculator(){},那有void啊!

Answer 3

counterFrame.add(resultPanel);
counterFrame.add(keyPanel);改为counterFrame.getContentPane().add(resultPanel);
counterFrame.getContentPane().add(keyPanel);

Answer 4

jFrame.setVisible(true);
写的好乱阿，ft

Answer 5

谢谢zhanghuazhanghome,你是对的，解决了让我们很郁闷的问题
也代我同学谢谢你