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
        }
    }

我的目标是用最少的代码更改重用startActivityForResult方法的当前实现。为此，我使用onActivityResultFromLauncher方法创建了一个包装器类和接口。

interface ActivityResultLauncherWrapper {

    fun launchIntentForResult(activity: FragmentActivity, intent: Intent, requestCode: Int, callBack: OnActivityResultListener)

    fun unregister()

    interface OnActivityResultListener {
        fun onActivityResultFromLauncher(requestCode: Int, resultCode: Int, data: Intent?)
    }
}

class ActivityResultLauncherWrapperImpl : ActivityResultLauncherWrapper {
    private var weakLauncher: WeakReference<ActivityResultLauncher<Intent>>? = null

    override fun launchIntentForResult(
            activity: FragmentActivity,
            intent: Intent,
            requestCode: Int,
            callBack: ActivityResultLauncherWrapper.OnActivityResultListener
    ) {

        weakLauncher = WeakReference(
                activity.registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
                    callBack.onActivityResultFromLauncher(requestCode, result.resultCode, result.data)
                }
        )

        weakLauncher?.get()?.launch(intent)
    }

    override fun unregister() {
        weakLauncher?.get()?.unregister()
    }
}

我在我的项目中使用匕首，我在需要的地方注入了包装器

@Inject
lateinit var activityResultLauncher: ActivityResultLauncherWrapper

但是包装器也可以直接实例化:

val activityResultLauncher = ActivityResultLauncherWrapper()

然后你必须用launchIntentForResult改变startActivityForResult方法。下面是一个从片段中调用它的例子:

activityResultLauncher.launchIntentForResult(
        requireActivity(),
        intent,
        REQUEST_CODE_CONSTANT,
        object: ActivityResultLauncherWrapper.OnActivityResultListener {
            override fun onActivityResultFromLauncher(requestCode: Int, resultCode: Int, data: Intent?) {
                /*do something*/
            }
        }
)

您将在匿名对象中收到结果。 你可以在Fragment或FragmentActivity中使用OnActivityResultListener，如果你实现了接口，并像这样重构当前的实现:

class MyFragment : Fragment(), OnActivityResultListener {
   
 ...
    
override fun onActivityResultFromLauncher(requestCode: Int, resultCode: Int, data: Intent?) {/*do somthing*/}

 ...

}

正如我们所知，Kotlin类ActivityResultLauncherWrapper也可以在java代码中使用。在我的项目中也有java类。这里有一个在Fragment中实现回调接口的例子:

public class MyFragment extends Fragment implements OnActivityResultListener {
    
...

    @Inject
    ActivityResultLauncherWrapper activityResultLauncher;
//ActivityResultLauncherWrapper activityResultLauncher = new ActivityResultLauncherWrapper()

...

public void launnchActivity(@NotNull Intent intent) {
        activityResultLauncher.launchIntentForResult(requireActivity(), intent, REQUEST_CODE_CONSTANT, this);
    }

...

 @Override
    public void onActivityResultFromLauncher(int requestCode, int resultCode, Intent data) {/*do somthing*/}
...
}

我希望这有助于为您的案例构建解决方案。

另一种方法是分3步完成。(考虑到你有一个startActivityForResult(0和onActivityResult()))

创建一个形式为var resultLauncher的变量:ActivityResultLauncher<Intent> 创建一个私有函数，在其中以这种基本格式初始化resultLauncher

resultLauncher=registerForActivityResult(ActivityResultContracts.StartActivityForResult()){result ->  

// copy paste the code from the onActivityResult replacing resultcode to result.resultCode  

if(result.resultcode==Activity.Result_OK){
val data=result.data // this data variable is of type intent and you can use it 

}else{
//code if you do not get the data 
}
}

使用startActivityForResult()返回行，并将其替换为resultLauncher.launch(intent)

在替换已弃用的方法startActivityForResult(…)时，需要遵循4个简单的步骤。

In place of overridden method onActivityResult(..) - ActivityResultLauncher<Intent> activityResultLaunch = registerForActivityResult( new ActivityResultContracts.StartActivityForResult(), new ActivityResultCallback<ActivityResult>() { @Override public void onActivityResult(ActivityResult result) { if (result.getResultCode() == 123) { // ToDo : Do your stuff... } else if(result.getResultCode() == 321) { // ToDo : Do your stuff... } } });

对于多个自定义请求，将条件附加为

if (result.getResultCode() == 123) {
..
} else if(result.getResultCode() == 131){
..
} // so on..

Imports : import androidx.activity.result.ActivityResult; import androidx.activity.result.ActivityResultCallback; import androidx.activity.result.ActivityResultLauncher; import androidx.activity.result.contract.ActivityResultContracts; In place of startActivityForResult(intent, 123), use Intent intent = new Intent(this, SampleActivity.class); activityResultLaunch.launch(intent); In SampleActivity.java class, while returning back to source activity, code will remain the same like - Intent intent = new Intent(); setResult(123, intent); finish();

编码快乐!：）