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)

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);
            }
        });
    }

}

这就是我如何替换多个requestCodes(把这段代码放在你的活动中):

    ActivityResultLauncher<Intent> launchCameraActivity = registerForActivityResult(
        new ActivityResultContracts.StartActivityForResult(),
        new ActivityResultCallback<ActivityResult>() {
            @Override
            public void onActivityResult(ActivityResult result) {
                if (result.getResultCode() == Activity.RESULT_OK) {
                    Intent data = result.getData();
                    Bitmap photoBitmap;
                    if(data != null && data.getExtras() != null){
                        photoBitmap = (Bitmap) data.getExtras().get("data");
                        if (photoBitmap != null) {
                            dataModel.setPhoto(ImageUtil.convert(photoBitmap));
                            imageTaken.setVisibility(View.VISIBLE);
                            imageTaken.setImageBitmap(photoBitmap);
                        }

                    }
                }
            }
        });

ActivityResultLauncher<Intent> launchCameraAndGalleryActivity = registerForActivityResult(
    new ActivityResultContracts.StartActivityForResult(),
    new ActivityResultCallback<ActivityResult>() {
        @Override
        public void onActivityResult(ActivityResult result) {
            if (result.getResultCode() == Activity.RESULT_OK) {
                
                Intent data = result.getData();
                Uri imageUri;
                if (data != null) {
                    imageUri = data.getData();
                    InputStream imageStream;
                    try {
                        imageStream = getContentResolver().openInputStream(imageUri);
                        Bitmap photoBitmap = BitmapFactory.decodeStream(imageStream);
                        dataModel.setOtherImage(ImageUtil.convert(photoBitmap));
                        documentImageTaken.setVisibility(View.VISIBLE);
                        documentImageTaken.setImageBitmap(photoBitmap);
                    }catch (FileNotFoundException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
    });

我是这样开展活动的:

                    Intent photoIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
                launchCameraAndGalleryActivity.launch(photoIntent );

Intent galleryIntent= new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
    launchCameraActivity.launch(galleryIntent);

分享我找到的解决方法

首先，使用registerForActivityResult为结果注册这个活动 这将返回一个类型为ActivityResultLauncher<Intent!> 像这样,

private val getResult =
        registerForActivityResult(
            ActivityResultContracts.StartActivityForResult()
        ) {
            if (it.resultCode == Activity.RESULT_OK) {
                val value = it.data?.getStringExtra("input")
            }
        }

现在，无论我们想在哪里启动result活动我们都可以使用getresult。launch(intent)

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

以下是我的解决方案:

在我们的项目中，我们有超过20次的startActivityForResult(和onActivityResult)。

我们希望尽可能少地更改代码(并继续使用请求代码)，同时引入一个优雅的解决方案以供将来使用。

既然我们很多开发人员都使用BaseActivity概念——为什么不利用它呢?

下面是BaseActivity:

abstract class BaseActivity : AppCompatActivity()
{
    private var requestCode: Int = -1
    private var resultHandler: ActivityResultLauncher<Intent>? = null

    override fun onCreate(savedInstanceState: Bundle?)
    {
        super.onCreate(savedInstanceState)
        registerForActivityResult()
    }

    private fun registerForActivityResult()
    {
        if (shouldRegisterForActivityResult())
        {
            resultHandler = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->

                onActivityResult(result.data, requestCode, result.resultCode)
                this.requestCode = -1
            }
        }
    }

   fun startActivityForResult(requestCode: Int, intent: Intent)
   {
       this.requestCode = requestCode
       resultHandler?.launch(intent)
   }

   protected open fun onActivityResult(data: Intent?, requestCode: Int, resultCode: Int)
   {
       // For sub activities
   }

   protected open fun shouldRegisterForActivityResult(): Boolean
   {
      // Sub activities that need the onActivityResult "mechanism", should override this and return true
       return false
   }
}

这是SubActivity:

class SubActivity : BaseActivity()
{
    companion object
    {
        private const val SOME_REQUEST_CODE = 300
    }

    private fun testActivityResult()
    {
        val intent = Intent(this, OtherActivity::class.java)
        startActivityForResult(SOME_REQUEST_CODE, intent)
    }

    override fun shouldRegisterForActivityResult(): Boolean
    {
        return true
    }

    override fun onActivityResult(data: Intent?, requestCode: Int, resultCode: Int)
    {
        if (requestCode == SOME_REQUEST_CODE)
        {
            // Yes!
        }
    }
}

希望它能帮助到别人