android---Activity间消息互传

当一个Activity1开启一个新的Activity2时，可以将一个Bundle对象绑定在Intent中进行传递，而Bundle对象中可以存储很多种类型的数据，支持的数据类型有int、string、ArrayList、List、boolean、byte、char等等，如果关闭Activity2返回Activity1时要传递数据，则Activity1需以startActivityForResult(intent,requestCode)方式开启Activity2,并且Axtivity2设置setResult(RESULT_OK,
intent)，这样当关闭Activity2时，就会触发Activity的回调函数onActivityResult();

完整代码如下：

Activity1


代码

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

btnjump=(Button)findViewById(R.id.btnload);
btnjump.setOnClickListener(this);
etname=(EditText)findViewById(R.id.actname);
etpwd=(EditText)findViewById(R.id.etpwd);
}

//被此Activity启动的Activity返回结果时触发的回调函数
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data){
if(resultCode==RESULT_OK){
Bundle bundle=data.getExtras();
Toast.makeText(this, bundle.getString("name")+"/"+bundle.getString("pwd"), Toast.LENGTH_LONG);
}
super.onActivityResult(requestCode, resultCode, data);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String name=etname.getText().toString();
String pwd=etpwd.getText().toString();
Intent intent = new Intent();
Bundle bundle=new Bundle();
bundle.putString("name", name);
bundle.putString("pwd", pwd);
intent.putExtras(bundle);

//requestCode大于等于0,当返回Activity时，会回调onActivityResult()函数
int requestCode=0;
//启动一个Activity，并且被启动的Activity返回结果时会触发回调函数
this.startActivityForResult(intent,requestCode);
}

Activity2:


代码

public class TwoActivity extends Activity {

public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
this.setContentView(R.layout.two);
TextView tvshow=(TextView)findViewById(R.id.tvShow);
Intent intent= this.getIntent();
Bundle bundle=intent.getExtras();
final String name=bundle.getString("name");
final String pwd=bundle.getString("pwd");
tvshow.setText(name+"/"+pwd);

Button btn=(Button)findViewById(R.id.btnback);
btn.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent data=new Intent();
Bundle extras = new Bundle();
extras.putString("name","返回:"+name );
extras.putString("pwd", "返回:"+pwd);
data.putExtras(extras);
TwoActivity.this.setResult(RESULT_OK, data);//返回数据
finish();
}
});
}
}