下面的代码在Kotlin片段中工作，用于检查蓝牙权限。年- 2022年

val intent = intent (BluetoothAdapter.ACTION_REQUEST_ENABLE)

        registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
            if (result.resultCode == Activity.RESULT_OK) {
                // There are no request codes
                val data: Intent? = result.data
                bluetoothAdapter.enable()
                Toast.makeText(context, "Permission Granted: ", Toast.LENGTH_SHORT).show()
                dynamicButton()
            }
            else{Toast.makeText(context, "You have to enable bluetooth to use this app.", Toast.LENGTH_SHORT).show()}
            
        }.launch(intent)

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。

ActivityResultLauncher<Intent> someActivityResultLauncher = registerForActivityResult(
        new ActivityResultContracts.StartActivityForResult(),
        new ActivityResultCallback<ActivityResult>() {
            @Override
            public void onActivityResult(ActivityResult result) {
                if (result.getResultCode() == Activity.RESULT_OK) {

                }
            }
        });

参考:Kotlin -从图库中选择图像

迄今为止我发现的最简单的Alernative

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.id.activity_main)

    var ivPhoto = findViewById<ImageView>(R.id.ivPhoto)
    var btnChoosePhoto = findViewById<Button>(R.id.btnChoosePhoto)

    

val getContent = registerForActivityResult(ActivityResultContracts.GetContent())  { uri: Uri? ->
            ivPhoto.setImageURI(uri)    // Handle the returned Uri
        }


    btnChoose.setOnClickListener {
        getContent.launch("image/*")
    }
    
    }

如果你像这样实现你的base Activity，你可以继续使用旧的startActivityForResult。 唯一的限制是你必须使用setResult(result, intent)在你的活动中设置结果。 关键是让结果将请求代码带回结果使用者。

public class MyBaseActivity extends AppCompatActivity {
    private ActivityResultLauncher<Intent> activityLauncher;
    protected static String ACTIVITY_REQUEST_CODE = "my.activity.request.code";
    protected _originalIntent; 

    public void launchActivityForResult(Intent intent, int requestCode){
        intent.putExtra(UGM_ACTIVITY_REQUEST_CODE, requestCode);
        activityLauncher.launch(intent);
    }

    //
    //In order to be signature compatible for the rest of derived activities, 
    //we will override the deprecated method with our own implementation!
    //
    @SuppressWarnings( "deprecation" )
    public void startActivityForResult(Intent intent, int requestCode){
        launchActivityForResult(intent, requestCode);
    }

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

    _originalIntent = getIntent();
        //set the default result
        setResult(Activity.RESULT_OK, _originalIntent);

        activityLauncher = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(), new ActivityResultCallback<ActivityResult>() {
            @Override
            public void onActivityResult(ActivityResult result) {
                Intent intent = result.getData();
                int requestCode = intent.getIntExtra(ACTIVITY_REQUEST_CODE, -1);
                MyBaseActivity.this.onActivityResult(requestCode, result.getResultCode(), intent);
            }
        });
    }

}

startActivityForResult和onActivityResult在android 10 API 30中已弃用，现在我们有了一种新的方法来使用registerForActivityResult来获得结果

resultContract =
    registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
        if (result.resultCode == Activity.RESULT_OK) {
            // There are no request codes
            val country = result.data?.getParcelableExtra<Country>("Country")
            showLiveDemoDialogue(country)
        }
    }

并启动活动

val intent = Intent(this, CountriesListActivity::class.java)
        resultContract.launch(intent)

但你应该在呼叫发射前注册然后发射到你想去的任何地方。 否则，您将得到这个异常

attempting to register while current state is RESUMED. LifecycleOwners must call register before they are STARTED.