dor506回答为我工作，因为我在我的大多数项目中使用BaseActivity，所以对我来说更容易在单个文件中更改代码，而不是我所有的活动。我已经写了这个代码的java版本。

BaseActivity代码:

private int requestCode = -1;
private ActivityResultLauncher<Intent> resultHandler = null;

 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mContext = this;

    registerForActivityResult();
}
  private final void registerForActivityResult() {
    if (shouldRegisterForActivityResult()) {
        this.resultHandler = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(),
                new ActivityResultCallback() {

            public void onActivityResult(Object var1) {
                this.onActivityResult((ActivityResult)var1);
            }

            public final void onActivityResult(ActivityResult result) {
                Intrinsics.checkNotNullExpressionValue(result, "result");
                AppActivityClass.onActivityResult(result.getData(), AppActivityClass.this.requestCode, result.getResultCode());
                AppActivityClass.this.requestCode = -1;
            }
        });
    }
}

public final void startActivityForResult(int requestCode, Intent intent) {
    this.requestCode = requestCode;
    if (resultHandler != null) {
        resultHandler.launch(intent);
    }
}

protected static void onActivityResult(Intent intent, int requestCode, int resultCode) {
}

protected Boolean shouldRegisterForActivityResult() {
    return false;
}

现在在任何活动中使用这样的代码:

 @Override
protected Boolean shouldRegisterForActivityResult() {
    return true;  // this will override the baseactivity method and we can use onactivityresult
}

  private void someMethod(){
    Intent i = new Intent(mContext,SomeOtherClassActivity.class);
    startActivityForResult(101,i);
}

  @Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == 101) {
        if (resultCode == RESULT_OK) {
            //revert from called class
        }
    }
}

我使用kotlin扩展，使它非常简单。在你的扩展中添加以下扩展功能。kt文件:

fun AppCompatActivity.startForResult(intent: Intent,
    onResult: (resultCode: Int, data: Intent?) -> Unit
) {
    this.registerForActivityResult(ActivityResultContracts.StartActivityForResult()) {result ->
        onResult(result.resultCode, result.data)
    }.launch(intent)
}

现在，在继承AppCompatActivity的任何活动中，你可以使用下面的简单代码:

val i = Intent(this, TargetActivity::class.java)
startForResult(i) { resultCode, data ->
   //put your code here like:
   if (resultCode == RESULT_OK) {
      //your code here...
      }
   }
}

更新 上述实现可能导致以下异常: java.lang.IllegalStateException: LifecycleOwner xxxx正在尝试注册，而当前状态为恢复。生命周期所有者必须在启动之前调用寄存器。

因此，registerForActivityResult应该提前调用，例如在onCreate之前。这是另一种解决方案。

在你的扩展中添加以下扩展功能。kt文件:

fun AppCompatActivity.registerForResult(onResult: (resultCode: Int, data: Intent?) -> Unit):
        ActivityResultLauncher<Intent> {
    return this.registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
        onResult(result.resultCode, result.data)
    }
}

现在，在继承AppCompatActivity的任何活动中，你可以使用下面的简单代码:

为每个需要结果的操作定义一个类成员变量

private val myActionResult = registerForResult { resultCode, data ->
   //put your code here like:
   if (resultCode == RESULT_OK) {
      //your code here...
      }
   }
}

启动动作

val i = Intent(this, TargetActivity::class.java)
myActionResult.launch(i)

在芬兰湾的科特林 我改变了我的代码

startActivityForResult(intent, Constants.MY_CODE_REQUEST)

and

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent) {
    super.onActivityResult(requestCode, resultCode, data)
    if (resultCode == Activity.RESULT_OK) {
        when (requestCode) {
            Constants.MY_CODE_REQUEST -> {
            ...
}

to

registerForActivityResult(StartActivityForResult()) { result ->
    onActivityResult(Constants.MY_CODE_REQUEST, result)
}.launch(intent)

and

private fun onActivityResult(requestCode: Int, result: ActivityResult) {
    if(result.resultCode == Activity.RESULT_OK) {
        val intent = result.data
        when (requestCode) {
            Constants.MY_CODE_REQUEST -> {
            ...

我希望这对你有用。: D

在我的情况下，我试图使用意图，我直接移动到下一个活动，而不使用谷歌登录。

对我有用的是:

在OnCreate中为登录按钮设置onClickListener:

     btnSignIn.setOnClickListener {
        signIn()
        }

    private fun signIn() {
        val intent = client.signInIntent
        mainActivityResultLauncher.launch(intent)
    }

在上面的代码中，我写了去下一个活动的意图，但我必须写client.signInIntent

    var mainActivityResultLauncher = registerForActivityResult(ActivityResultContracts.StartActivityForResult()){ result ->

        if(result.resultCode == Activity.RESULT_OK){
            val data = result.data
            val task = GoogleSignIn.getSignedInAccountFromIntent(data)
            try {
                // Google Sign In was successful, authenticate with Firebase
                val account = task.getResult(ApiException::class.java)!!
                Log.d(TAG, "firebaseAuthWithGoogle:" + account.id)
                firebaseAuthWithGoogle(account.idToken!!)
            } catch (e: ApiException) {
                // Google Sign In failed, update UI appropriately
                Log.w(TAG, "Google sign in failed", e)
            }
        }
    }

添加到muntashir akon和abhijeet的答案，你可以通过在意图中传递值来修改新格式，使其像旧格式一样工作，例如:

// calling class
....
val i = Intent(this@GEBShopActivity, BarcodeScannerActivity::class.java)
when(loadedFragment){   
   is ShopHomeFragment      -> { i.putExtra("myapp.result.code", CODE_ACTIVITY_SCAN_LIST_MAINT) }
   is ShopListFragment      -> { i.putExtra("myapp.result.code", CODE_ACTIVITY_SCAN_LIST_MAINT) }
   is ShopItemMaintFragment -> { i.putExtra("myapp.result.code", CODE_ACTIVITY_SCAN_ITEM_MAINT) }
   is ShopPriceFragment     -> { i.putExtra("myapp.result.code", CODE_ACTIVITY_PRICE_CAPTURE) }
   is ShopCompareFragment   -> { i.putExtra("myapp.result.code", CODE_ACTIVITY_PRICE_CAPTURE) }
}
shopFragmentLauncher.launch(i)
....

// called class
....
val resultIntent = Intent()
val bundle = Bundle()
bundle.putStringArrayList("scanned_barcodes", scanned_barcodes)
bundle.putInt("scan_count", scan_count)
resultIntent.putExtras(bundle)
resultIntent.putExtra("myapp.result.code", intent.getIntExtra("myapp.result.code", 0))
setResult(Activity.RESULT_OK, resultIntent)
....

这将允许您保持类的调用相同，只需要额外的一行来添加原始调用的结果代码。还允许您创建一个可重用的启动程序实例。

从现在开始，startActivityForResult()已经被弃用，所以使用new方法代替。

芬兰湾的科特林的例子

    fun openActivityForResult() {
        startForResult.launch(Intent(this, AnotherActivity::class.java))
    }


    val startForResult = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { 
    result: ActivityResult ->
        if (result.resultCode == Activity.RESULT_OK) {
            val intent = result.data
            // Handle the Intent
            //do stuff here
        }
    }