四则运算之主要代码

Mainactivity:

public class MainActivity extends Activity {  

Button start,end,wa;  

int yourChose=-1; 

    private void showSinChosDia()      { 

        final String[] mList={"普通","困难","加法练习","减法练习","乘法练习","除法练习"};   

       yourChose=-1;     

     AlertDialog.Builder sinChosDia=new AlertDialog.Builder(MainActivity.this);      

    sinChosDia.setTitle("难度/单项练习");     

     sinChosDia.setSingleChoiceItems(mList, 0, new DialogInterface.OnClickListener() {                            @Override             

public void onClick(DialogInterface dialog, int which) {           

       // TODO Auto-generated method stub          

        yourChose=which;                        

        }        

  }); 

  sinChosDia.setPositiveButton("确定", new DialogInterface.OnClickListener() { 
             
            @Override 
            public void onClick(DialogInterface dialog, int which) { 
                // TODO Auto-generated method stub 
             
             
                if(yourChose==0) 
                { 
                 Intent intent = new Intent(MainActivity.this, CalActivity.class);
                 startActivity(intent);
                } 
                if(yourChose==1)
                {
                 Intent intent = new Intent(MainActivity.this, CalActivity1.class);
                 startActivity(intent);
                }
                if(yourChose==2)
                {
                 Intent intent = new Intent(MainActivity.this, CalActivity2.class);
                 startActivity(intent);
                }
                if(yourChose==3)
                {
                 Intent intent = new Intent(MainActivity.this, CalActivity3.class);
                 startActivity(intent);
                }
                if(yourChose==4)
                {
                 Intent intent = new Intent(MainActivity.this, CalActivity4.class);
                 startActivity(intent);
                }
                if(yourChose==5)
                {
                 Intent intent = new Intent(MainActivity.this, CalActivity5.class);
                 startActivity(intent);
                }
            } 
        }); 
        sinChosDia.create().show(); 
    } 

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final DBHelper helper = new DBHelper(this);
  final Cursor c = helper.query();
        start=(Button) findViewById(R.id.button1);
        start.setOnClickListener(new Button.OnClickListener(){
       
   @Override
   
   public void onClick(View v) {
    // TODO Auto-generated method stub
    
    showSinChosDia();
    
   }
        });
        wa=(Button) findViewById(R.id.button2);
        wa.setOnClickListener(new Button.OnClickListener(){
         
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    if(!c.moveToNext())
    {
     helper.close();
     AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
     builder.setCancelable(false);
     builder.setTitle("结束"); 
     builder.setMessage("无错题"); 
     builder.setPositiveButton("确定", new DialogInterface.OnClickListener() { 
      
         public void onClick(DialogInterface dialog, int whichButton) { 
         } 
     }); 
     builder.create().show();
    }
    else{
     Intent intent = new Intent(MainActivity.this, ShowDB.class);
     startActivity(intent);
    }
   }
        });
        end=(Button) findViewById(R.id.button3);
        end.setOnClickListener(new Button.OnClickListener(){
         
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    System.exit(0);
   }
        });
    }
   
}

CalActivity:

public class CalActivity extends Activity {  

RelativeLayout rl1;  

ImageView im;  int op;

    int a;     int b;     int n=0;  

   int w=0;     String r;

    Double answer,respon;   

  TextView textview1,textview2;  

   EditText editText;  

   Button button;

  @Override   protected void onCreate(Bundle savedInstanceState) {  

  super.onCreate(savedInstanceState);

   setContentView(R.layout.cal_main);  

  ActionBar actionBar = getActionBar();   

    actionBar.setDisplayShowHomeEnabled(true);     

  actionBar.setDisplayHomeAsUpEnabled(true);

   rl1=(RelativeLayout)findViewById(R.id.RelativeLayout1);

   im=(ImageView)findViewById(R.id.imageView1);   

textview1=(TextView)findViewById(R.id.textView1);  

  textview2=(TextView)findViewById(R.id.textView2);

   editText=(EditText)findViewById(R.id.EditText1);

 a =new Random().nextInt(100);
         b =new Random().nextInt(100);
         op=new Random().nextInt(4);
         switch(op)//分支语句，判断OP是哪种情况
         {
         case 0:
          textview1.setText(a+"+"+b+"=");
             answer=(double) (a+b);
             break;
         case 1:
          textview1.setText(a+"-"+b+"=");
             answer=(double) (a-b);
             break;
         case 2:
          a =new Random().nextInt(10);
          b =new Random().nextInt(10);
          textview1.setText(a+"*"+b+"=");
             answer=(double) (a*b);
             break;
         case 3:
          a =new Random().nextInt(10);
          b =new Random().nextInt(10);
             while(b==0){
                 b =new Random().nextInt(10);
             }

  textview1.setText(a+"/"+b+"=");     

         BigDecimal   x   =   new   BigDecimal((double)a/b);  //保留2位小数。  

            answer  =   x.setScale(2,   BigDecimal.ROUND_HALF_UP).doubleValue();            

                break;          }   

       button=(Button)findViewById(R.id.button4);       

   button.setOnClickListener(new Button.OnClickListener(){

    @Override     public void onClick(View arg0) {     

 // TODO Auto-generated method stub   

   if(!checkInteger(editText.getText().toString()))      {    

   AlertDialog.Builder builder = new AlertDialog.Builder(CalActivity.this);

      builder.setCancelable(false);    

   builder.setTitle("错误");       

 builder.setMessage("你输入的信息有错");

        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() { 

                  public void onClick(DialogInterface dialog, int whichButton) {        

                }        });       

builder.create().show();     

  editText.setText("");   

    return;    

  }     

 respon=Double.parseDouble(editText.getText().toString());  

    r=textview1.getText().toString();  

    ContentValues values = new ContentValues();  

    values.put("problem", r);           

        values.put("answer", answer);   

   editText.setText("");

     n++;

     if(respon.equals(answer))      {     

  im.setImageResource(R.drawable.d);  

     textview2.setText("你答对了！");

     }      else{    

   im.setImageResource(R.drawable.c);  

     DBHelper helper = new DBHelper(getApplicationContext());

      final Cursor c = helper.query();     

  helper.insert(values);   

   w++;     

  textview2.setText("你答错了！ "+r+answer);  

     helper.close();      }      if(n<5)   

   {       a =new Random().nextInt(100);  

           b =new Random().nextInt(100);    

         op=new Random().nextInt(4);    

         switch(op)             {        

     case 0:              textview1.setText(a+"+"+b+"=");

                answer=(double) (a+b);             

    break;             case 1:              textview1.setText(a+"-"+b+"=");    

             answer=(double) (a-b);             

    break;             case 2:              a =new Random().nextInt(10);    

          b =new Random().nextInt(10);       

       textview1.setText(a+"*"+b+"=");            

     answer=(double) (a*b);                 break;      

       case 3:              a =new Random().nextInt(10);     

         b =new Random().nextInt(10);               

  while(b==0){                     b =new Random().nextInt(10);      

           }               

  textview1.setText(a+"/"+b+"=");         

        BigDecimal   x   =   new   BigDecimal((double)a/b);      

            answer  =   x.setScale(2,   BigDecimal.ROUND_HALF_UP).doubleValue();                                  break;             }      }    

  else      {    

   int right=n-w;      

 double rvate=(double)right/n*100;    

   AlertDialog.Builder builder = new AlertDialog.Builder(CalActivity.this);

      builder.setCancelable(false);      

 builder.setTitle("结束");      

  builder.setMessage("你答对了"+right+"题"+" "+"答错了"+w+"题"+" "+"正确率为"+rvate+"%");        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {   

                 public void onClick(DialogInterface dialog, int whichButton) {    

         Intent intent = new Intent(CalActivity.this, MainActivity.class);   

         intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);     

       startActivity(intent);           }        }); 

      builder.create().show();      }     }               });  

         }   public boolean checkInteger(String text) {  

        /*      当输入的文本去掉前后空格长度为0时返回false  */     

     if(text.trim().length()==0){                  return false;    

      }          try{                  Double.parseDouble(text);     

     }catch(Exception e){                  /*      无法转换为整数时返回false   */       

           return false;          }

         return true;  }   @Override    

  public boolean onCreateOptionsMenu(Menu menu) {  

     // TODO Auto-generated method stub    

   getMenuInflater().inflate(R.menu.main, menu);    

   return super.onCreateOptionsMenu(menu);   

   }      @Override  

    public boolean onOptionsItemSelected(MenuItem item) {  

     // TODO Auto-generated method stub       item.setChecked(true);   

 switch (item.getItemId()) {    case android.R.id.home:   

  //创建启动MainActivity的Intent     Intent intent1=new Intent(this,MainActivity.class);  

   //添加额外的Flag，将Activity栈中处于MainActivity之上的Activity弹出     intent1.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);  

   startActivity(intent1);     break;

   case R.id.item4:

    item.setChecked(true);   

  rl1.setBackgroundDrawable(getResources().getDrawable(android.R.color.black));   

  break;    case R.id.item5:  

   item.setChecked(true);  

   rl1.setBackgroundDrawable(getResources().getDrawable(R.drawable.bg1));

    break;    case R.id.item6:

    item.setChecked(true);   

  rl1.setBackgroundDrawable(getResources().getDrawable(R.drawable.bg3));  

   break;    case R.id.item7:   

  item.setChecked(true);     textview1.setTextColor(Color.YELLOW);    

 textview2.setTextColor(Color.YELLOW);  

   editText.setTextColor(Color.YELLOW);  

   button.setTextColor(Color.YELLOW);   

  break;    case R.id.item8:     item.setChecked(true);  

   textview1.setTextColor(Color.BLUE);  

   textview2.setTextColor(Color.BLUE);     

editText.setTextColor(Color.BLUE);   

  button.setTextColor(Color.BLUE);  

   break;    case R.id.item9:     item.setChecked(true);

    textview1.setTextColor(Color.RED);   

  textview2.setTextColor(Color.RED);    

 editText.setTextColor(Color.RED);  

   button.setTextColor(Color.RED);

    break;    case R.id.item10:     item.setChecked(true);  

   textview1.setTextColor(Color.BLACK);

    textview2.setTextColor(Color.BLACK);   

  editText.setTextColor(Color.BLACK);

    button.setTextColor(Color.BLACK);

    break;    case R.id.item11:     item.setChecked(true);  

   textview1.setTextSize(10);   

  textview2.setTextSize(10);    

 editText.setTextSize(10);     button.setTextSize(10);

    break;    case R.id.item12:     item.setChecked(true);

    textview1.setTextSize(20);  

   textview2.setTextSize(20);     editText.setTextSize(20);

    button.setTextSize(20);    

 break;    case R.id.item13:     item.setChecked(true);     

textview1.setTextSize(30);     textview2.setTextSize(30);  

   editText.setTextSize(30);     button.setTextSize(30);   

  break;

   default:     break;    }

      return super.onOptionsItemSelected(item);      }

  }