java - 为什么我的值没有在 Android Studio 中使用 startActivityForResult() 在 Activity 之间传递？

Question

我有两个按钮，单击它们时，我想将 1 或 2 传递给第二个 Activity 。我使用了intent.putExtra和intent.getExtra，但是当我检查第二个 Activity 中的变量值时，它始终为0。

主要 Activity

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    oneDownButton = (Button) findViewById(R.id.oneDownButton);
    twoDownButton = (Button) findViewById(R.id.twoDownButton);
    oneDownButton.setOnClickListener(this);
    twoDownButton.setOnClickListener(this);
}
@Override
public void onClick(View v)
{
    Intent intent = new Intent(this, TheCode.class);


    switch (v.getId())
    {
        case R.id.oneDownButton:
            intent.putExtra("TAKE_DOWN_NUMBER", 1);
            startActivityForResult(intent, REQUEST_1);
            break;
        case R.id.twoDownButton:
            intent.putExtra("TAKE_DOWN_NUMBER", 2);
            startActivityForResult(intent, REQUEST_1);
            break;
    }

}

代码 Activity

 @Override
protected void onResume()
{
    super.onResume();

    // Get the game state sent from the main activity
    Intent intent = getIntent();
    takeDownNumber = intent.getIntExtra("TAKE_DOWN_NUMBER", 0);
}
@Override
public void onClick(View v)
{
    bugsMessage = "";
    Intent returnIntent = new Intent(this, MainActivity.class);
    returnIntent.putExtra(MainActivity.BUGS_MESSAGE, bugsMessage);
    setResult(Activity.RESULT_OK, returnIntent);
    finish();
}

Answer 1

您必须使用 onCreate Bundle 来获取额外的值，使用下面的代码:

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

oneDownButton = (Button) findViewById(R.id.oneDownButton);
twoDownButton = (Button) findViewById(R.id.twoDownButton);
oneDownButton.setOnClickListener(this);
twoDownButton.setOnClickListener(this);
}
@Override
public void onClick(View v)
{
Intent intent = new Intent(this, TheCode.class);


switch (v.getId())
{
    case R.id.oneDownButton:
        intent.putExtra("TAKE_DOWN_NUMBER", 1);
        startActivity(intent, REQUEST_1);
        break;
    case R.id.twoDownButton:
        intent.putExtra("TAKE_DOWN_NUMBER", 2);
        startActivity(intent, REQUEST_1);
        break;
}

}

代码 Activity :

 public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
    setContentView(R.layout.secondactivity);      

    Intent intent = getIntent();
    Bundle bd = intent.getExtras();       
    if(bd != null)
    {
   //you must use bundle in oncreate method
     takeDownNumber = bd.get("TAKE_DOWN_NUMBER");

    }
}