Android intent数据传递

1. 主叫Activity向被叫Activity传递数据：

（1）主叫Activity写数据：

Intent intent = new Intent(action);
intent.putExtra("key", "value");
startActivity(intent);

   

（2）被叫Activity读数据：

Intent intent = getIntent();  
String strFromCaller = intent.getStringExtra("key");  

2. 被叫Activity向主叫Activity放回数据：

（1）主叫Activity以startActivityForResult()方式启动被叫Activity：

Intent intent = new Intent();  
intent.setClass(getApplicationContext(), NewAcitvity.class);  
// START_NEWACTIVITY is a predefined constant to identify the Activity invoked by this intent.  
startActivityForResult(intent, START_NEWACTIVITY);  

（2）被叫Activity写数据：

Uri uri = Uri.parse("back info");  
Intent data = new Intent(null, uri);  
data.putExtra("key", "value");  
setResult(Activity.RESULT_OK, data);  

（3）主叫Activity读数据：

@Override  
protected void onActivityResult(int requestCode, int resultCode, Intent data)  
{  
    super.onActivityResult(requestCode, resultCode, data);  
    switch (requestCode)  
    {  
        case START_NEWACTIVITY:  
            if (resultCode == Activity.RESULT_OK)  
            {  
                Toast.makeText(this, data.getStringExtra("key"), Toast.LENGTH_LONG).show();  
//              Toast.makeText(this, data.getData().toString(), Toast.LENGTH_LONG).show();  
            }  
            break;  
    }  
}