完成后继续onCreate流程()

Question

我想从onCreate方法内部完成一个活动.当我打电话时finish(),onDestroy()没有立即调用,代码不断流过finish().onDestroy()直到onCreate()结束括号后才调用.

根据onCreate()developer.android.com/reference上的说明.

您可以在此函数中调用finish(),在这种情况下,将立即调用onDestroy(),而不执行任何其余的活动生命周期(onStart(),onResume(),onPause()等).

我问的原因是:我想检查传递给Bundle的数据onCreate().当然我可以控制传递的内容onCreate,但我仍然认为应该在交付时进行检查.

我的代码包含class A,它启动Activity B.我认为不应该调用最后两个"if of clause子句"标签,因为语句中的finish方法if应该销毁了活动.它与if子句无关,因为第二次finish()调用后的标记行仍然被读取.

我的代码:

A级

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

    // goToBButton: when pressed sends message to class B.    
    Button goToBButton = (Button)this.findViewById(R.id.go_to__b_btn);
    goToBButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick (View v) {      
            Log.i(TAG,"A Class: goToBButton, onClick");
            Intent i = new Intent(A.this, B.class);
            startActivityForResult(i,REQ_TO_B);
        }       
    });                
} // end onCreate

我的代码ClassB

    public class B extends Activity{

private static final String TAG = "tag";

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

  // set as true, should always print Tag: one line before first finish"
  if (true)  {

    Log.i(TAG,"B Class: one line before 1st finish");
    finish();
  }

  // shouldn't get here after first finish
  Log.i(TAG,"B Class: outside of if clause, before second finish");
  finish();
  // shouldn't get here after second finish
  Log.i(TAG,"B Class: outside of if clause, after finish");                  
   } // end onCreate


@Override
public void onStart () {
    super.onStart();
    Log.i(TAG,"B Class: onStart");
}

@Override
public void onRestart() {
    super.onRestart();
    Log.i(TAG,"B Class: onRestart");
}

@Override
public void onResume () {
    super.onResume();
    Log.i(TAG,"B Class: onResume");
}

@Override
public void onPause () {
    super.onPause();
    Log.i(TAG,"B Class: onPause");
}

@Override
public void onStop () {
    super.onStop();
    Log.i(TAG,"B Class: onStop");
}

@Override
public void onDestroy () {
    super.onDestroy();
    Log.i(TAG,"B Class: onDestroy");
}

 } // end B Class

以下是我的代码的结果:

11-26 15:53:40.456:INFO/tag(699):A类:goToBButton,onClick

11-26 15:53:40.636:INFO/tag(699):A类:onPause

11-26 15:53:40.865:INFO/tag(699):B类:第一次完成前一行

11-26 15:53:40.896:INFO/tag(699):B类:if子句之外,第二次完成之前

11-26 15:53:40.917:INFO/tag(699):B类:在if子句之外,在完成之后

11-26 15:53:41.035:INFO/tag(699):A类:onResume

11-26 15:53:41.165:INFO/tag(699):B类:onDestroy

Answer 1

我猜这是因为finish()不会导致onCreate方法返回.您可以尝试简单地添加

finish();
return;

或者使用if else

@Override
public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.layoutb);
  if(good data){
      //do stuff
  }else{
      finish();
  }
}

Answer 2

finish()在onCreate()将控制返回到系统之前似乎不起作用.请参考这篇文章:关于android中的finish().如果您不希望在调用完成后执行任何代码,则必须考虑此问题.

希望能帮助到你.