不同 Activity 之间的数据传递

主activity

protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  Button button=(Button)findViewById(R.id.button1);
  button.setOnClickListener(new OnClickListener(){
   public void onClick(View v)
   {
    Intent intent=new Intent();                      //声明一个intent
    intent.setClass(MainActivity.this, main2.class);   //设置intent
    Bundle bundle=new Bundle();                               //声明一个bundle
    RadioButton rb=(RadioButton)findViewById(R.id.radio0);  
    String sex="";
    if(rb.isChecked())               //获取大家选中的是男m还是女
w     sex="M";
    else
     sex="W";
    bundle.putString("sex", sex);  //把获取的值放到bundle中
    
    EditText edittext=(EditText)findViewById(R.id.editText1);
    double height=Double.parseDouble(edittext.getText().toString());  //获取身高
    bundle.putDouble("height", height);   //把获取的值放到bundle中
    intent.putExtras(bundle);              //把bundle放到intent中
    startActivity(intent);
    
   }
  });
 }

 

 

显示activity

protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main2);
  TextView tv=(TextView)findViewById(R.id.textView9);
  Bundle bundle=this.getIntent().getExtras();                     //把intent中获取值
  String sex="";
  if(bundle.getString("sex").equals("M"))              //获取男或女
   sex="男";
  else
   sex="女";
  Double height=bundle.getDouble("height");             //获取身高
  
  tv.setText("你的姓别："+sex+"\n你的身高："+height+"\n你的标准体重是"+ weight + "公斤");
  
 }

/* 四舍五入的method */
private String format(double num) {
NumberFormat formatter = new DecimalFormat("0.00");
String s = formatter.format(num);
return s;
}

 

/* 以findViewById()取得Button 对象，并添加onClickListener */
private String getWeight(String sex, double height) {
String weight = "";
if (sex.equals("M")) {
weight = format((height - 80) * 0.7);
} else {
weight = format((height - 70) * 0.6);
}
return weight;
}
}