java在安卓 studio中的活动之间传递数据

Question

我正在开发一个应用程序，需要将信息从我的新活动传递到我的主要活动

一开始我试着不使用两个活动，而是使用editText，然后将信息传递给textView

public class MainActivity extends AppCompatActivity implements
        DatePickerDialog.OnDateSetListener,TimePickerDialog.OnTimeSetListener{
private static int PLACE = 0;
private ArrayList<TextView> notes = new ArrayList<TextView>();
private FloatingActionButton makeNoteFloatingActionButton,saveFloatingActionButton;
private Button setTimeButton;
private int day,month,year,hour,minute;
private int dayFinal,monthFinal,yearFinal,hourFinal,minuteFinal;
private String savedNote;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    makeNoteFloatingActionButton = (FloatingActionButton)findViewById(R.id.makeNoteFloatingActionButton);
    saveFloatingActionButton = (FloatingActionButton)findViewById(R.id.saveFloatingActionButton);
    setTimeButton = (Button)findViewById(R.id.setTimeButton);


    makeNoteFloatingActionButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(MainActivity.this,pop.class);
            intent.putExtra("note",);
            startActivity(intent);
        }
    });

另一类

public class MainActivity extends AppCompatActivity implements
        DatePickerDialog.OnDateSetListener,TimePickerDialog.OnTimeSetListener{
private static int PLACE = 0;
private ArrayList<TextView> notes = new ArrayList<TextView>();
private FloatingActionButton makeNoteFloatingActionButton,saveFloatingActionButton;
private Button setTimeButton;
private int day,month,year,hour,minute;
private int dayFinal,monthFinal,yearFinal,hourFinal,minuteFinal;
private String savedNote;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    makeNoteFloatingActionButton = (FloatingActionButton)findViewById(R.id.makeNoteFloatingActionButton);
    saveFloatingActionButton = (FloatingActionButton)findViewById(R.id.saveFloatingActionButton);
    setTimeButton = (Button)findViewById(R.id.setTimeButton);


    makeNoteFloatingActionButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(MainActivity.this,pop.class);
            intent.putExtra("note",);
            startActivity(intent);
        }
    });

我的目标是编写我需要的文本，并以文本视图的形式将其传递给主要活动

Answer 1

最好的解决方案是使用startActivityforResult（）。这样，您就可以始终完成返回EditText值的第二个活动

1. 将第一个活动中的startActivity（）替换为startActivityForResult（）

    Intent intent = new Intent(MainActivity.this,pop.class);
   startActivityForResult(intent, 101); // 101 is the unique request code

2. 在第二个活动中，从EdiText获取值后，执行以下操作

   意图=新意图（）； 意图putExtra（“注释”、“编辑文本值”）

   //设置结果并完成此活动

   setResult(Activity.RESULT_OK, intent);
   finish();
   

3. 从活动1中的onActivityResult（）中获取“note”的键值

   @Override ActivityResult上受保护的void（int请求代码、int结果代码、意图数据）{

   switch (requestCode) { case 101: // unique request code to obtain the intent data if (resultCode == RESULT_OK) { String note = data.getStringExtra(“note”); } break; } }

还要确保使用正确的命名约定，使用Pop作为类名，而不是Pop

Answer 2

主要活动：

    public void onClick(View v) {
        Intent intent = new Intent(MainActivity.this,pop.class);
        intent.putExtra("note", note);
        startActivity(intent);
    }

另一个类：

     public class AnotherClass{
        Intent intent = getIntent();
        String note = intent.getStringExtra("note");
     }