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);
            }
        });
    }

}

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
        }
    }

对于那些具有多个requestCode的片段，并且如果您不确定如何处理这些requestCode的多个结果，那么您需要了解requestCode在新方法中是无用的。

我想象你以前的编码方式是这样的:

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
    if (resultCode == Activity.RESULT_CODE) {
        when (requestCode) {
            REQUEST_TAKE_PHOTO -> {
                // handle photo from camera
            }
            REQUEST_PICK_IMAGE_FROM_GALLERY -> {
                // handle image from gallery
            }
        }
    }
}

在新的API中，你需要在一个单独的ActivityResultContract中实现每个请求的结果:

val takePhotoForResult = registerForActivityResult(StartActivityForResult()) { result: ActivityResult ->
    if (result.resultCode == Activity.RESULT_OK) {
        val intent = result.data
        // handle photo from camera
    }
}

val pickImageFromGalleryForResult = registerForActivityResult(StartActivityForResult()) { result: ActivityResult ->
    if (result.resultCode == Activity.RESULT_OK) {
        val intent = result.data
        // handle image from gallery
    }
}

然后你需要像这样开始这些活动/意图:

private fun startTakePhotoActivity() {
    takePhotoForResult.launch(Intent(requireActivity(), TakePhotoActivity::class.java))
}

private fun pickImageFromGallery() {
    val pickIntent = Intent(Intent.ACTION_PICK)
    pickIntent.setDataAndType(
        MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
        "image/*"
    )
    pickImageFromGalleryForResult.launch(pickIntent)
}

通过这样做，你可以在你的项目中摆脱数百个const val REQUEST_值。

一个简单的例子:registerForActivityResult和requestmultiplepermission from Activity和Fragment

请求活动以获得活动的结果

registerForActivityResult(
    ActivityResultContracts.StartActivityForResult()
) { activityResult ->
    if (activityResult.resultCode == Activity.RESULT_OK) {
        //...
    }
}

检查ActivityResult

向活动请求许可?

registerForActivityResult(
    ActivityResultContracts.RequestMultiplePermissions()
) {
    //it: Map<String, Boolean>
}

从片段?

使用相同的方法，但确保将这些实现放在初始化中，onAttach()或onCreate()

Kotlin版本的@Muntashir阿肯解决方案

class BetterActivityResult<Input, Result> private constructor(
  caller : ActivityResultCaller,
  contract : ActivityResultContract<Input, Result>,
  var onActivityResult : ((Result) -> Unit)?,
) {

private val launcher : ActivityResultLauncher<Input> =
   caller.registerForActivityResult(contract) { onActivityResult?.invoke(it) }

  /**
   * Launch activity, same as [ActivityResultLauncher.launch] except that it 
   * allows a callback
   * executed after receiving a result from the target activity.
   */
  /**
   * Same as [.launch] with last parameter set to `null`.
   */
  @JvmOverloads
  fun launch(
     input : Input,
     onActivityResult : ((Result) -> Unit)? = this.onActivityResult,
  ) {
    this.onActivityResult = onActivityResult
    launcher.launch(input)
  }

  companion object {
  /**
   * Register activity result using a [ActivityResultContract] and an in-place 
   * activity result callback like
   * the default approach. You can still customise callback using [.launch].
   */
  fun <Input, Result> registerForActivityResult(
    caller : ActivityResultCaller,
    contract : ActivityResultContract<Input, Result>,
    onActivityResult : ((Result) -> Unit)?,
  ) : BetterActivityResult<Input, Result> {
    return BetterActivityResult(caller, contract, onActivityResult)
  }

  /**
   * Same as [.registerForActivityResult] except
   * the last argument is set to `null`.
   */
  fun <Input, Result> registerForActivityResult(
    caller : ActivityResultCaller,
    contract : ActivityResultContract<Input, Result>,
  ) : BetterActivityResult<Input, Result> {
    return registerForActivityResult(caller, contract, null)
  }

  /**
   * Specialised method for launching new activities.
   */
  fun registerActivityForResult(
    caller : ActivityResultCaller,
  ) : BetterActivityResult<Intent, ActivityResult> {
    return registerForActivityResult(caller, StartActivityForResult())
  }
 }
}

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!：）