从 Activity B 到 Activity A 的额外内容

Question

我有两个活动。在 Activity A 中我有 Textview。单击此按钮后，我使用 EditText 转到 Activity B。

如何将 activity B 中 EditText 的值传回 activity A 中的 TextView，同时保持 activity A 的原始状态正在处理中？

Answer 1

像这样写ActivityA

public class MainActivity extends Activity {  
TextView textView1;  
Button button1;  
@Override  
protected void onCreate(Bundle savedInstanceState) {  
    super.onCreate(savedInstanceState);  
    setContentView(R.layout.activity_main);  
    textView1=(TextView)findViewById(R.id.textView1);  
    button1=(Button)findViewById(R.id.button1);  
    button1.setOnClickListener(new OnClickListener() {  
        @Override  
        public void onClick(View arg0) {  
            Intent intent=new Intent(MainActivity.this,SecondActivity.class);  
            startActivityForResult(intent, 2);// Activity is started with requestCode 2  
        }  
    });  
}  
// Call Back method  to get the Message form other Activity  
@Override  
   protected void onActivityResult(int requestCode, int resultCode, Intent data)  
   {  
             super.onActivityResult(requestCode, resultCode, data);  
              // check if the request code is same as what is passed  here it is 2  
               if(requestCode==2)  
                     {  
                        String message=data.getStringExtra("MESSAGE");   
                        textView1.setText(message);  
                     }  
 }  
 }

代替开始Activity使用startActivityForResult

Intent intent=new Intent(MainActivity.this,SecondActivity.class);  
        startActivityForResult(intent, 2);// Activity is started with requestCode 2

并在 Activity B 中设置这样的结果

   Intent intent=new Intent();  
                intent.putExtra("MESSAGE",message);  
                setResult(2,intent);  
                finish();//finishing activity

你可以在 Activity A(onActivityResult)

中得到 intent.putExtra("MESSAGE",message);

从 Activity B 到 Activity A 的额外内容

Extra from Activity B to Activity A

android

savechanges

extra

android-activity

android-studio