1、界面设计：activity_main.xml

1 
      2 
     
       7  8     
      15     
      23     
      31     
      40     
      46     
      52     
      58 
     

2、res/values/strings.xml

1 
      2 
     
       3  4     
      
       BMI
       5         
      
       身高(cm)
       6         
      
       体重(kg)
       7         
      
       计算BMI值
       8         
      
       你的BMI值是
       9     
      
       Hello world!
      10     
      
       Settings
      11 12 
     

3、res/values/advice.xml

1 
     2 
     
      3     
      
       你该多吃点
      4     
      
       体型很棒喔
      5     
      
       你该节食了
      6     
     

4、主程序

1 package example.bmi; 2  3 import java.text.DecimalFormat; 4  5 import android.os.Bundle; 6 import android.app.Activity; 7 import android.view.Menu; 8 import android.view.View; 9 import android.view.View.OnClickListener;10 import android.widget.Button;11 import android.widget.EditText;12 import android.widget.TextView;13 14 public class MainActivity extends Activity {15 16     @Override17     protected void onCreate(Bundle savedInstanceState) {18         super.onCreate(savedInstanceState);19         setContentView(R.layout.activity_main);20         21         //Listen for button clicks22         Button button=(Button)findViewById(R.id.submit);23         button.setOnClickListener(calcBMI);24     }25     26     private OnClickListener calcBMI=new OnClickListener()27     {28         public void onClick(View v)29         {30             DecimalFormat nf=new DecimalFormat("0.00");31             EditText fieldheight=(EditText)findViewById(R.id.height);32             EditText fieldweight=(EditText)findViewById(R.id.weight);33             double height=Double.parseDouble(fieldheight.getText().toString())/100;34             double weight=Double.parseDouble(fieldweight.getText().toString());35             double BMI=weight/(height*height);36             TextView result=(TextView)findViewById(R.id.result);37             result.setText("Your BMI is"+nf.format(BMI));38             //give health advice39             TextView fieldsuggest=(TextView)findViewById(R.id.suggest);40             if(BMI>25)41             {42                 fieldsuggest.setText(R.string.advice_heavy);43             }44             else if(BMI<20)45             {46                 fieldsuggest.setText(R.string.advice_light);47                }48             else49             {50                 fieldsuggest.setText(R.string.advice_average);51             }52         }    53     };54 55     @Override56     public boolean onCreateOptionsMenu(Menu menu) {57         // Inflate the menu; this adds items to the action bar if it is present.58         getMenuInflater().inflate(R.menu.activity_main, menu);59         return true;60     }61     62 }