结合上面的答案，我有一个与旧方法兼容的方法startActivityForResult()保持使用requestCode而不改变旧的代码结构:

ActivityLauncher.class

public class ActivityLauncher {

private final ActivityResultLauncher<Intent> launcher;
private ActivityResultCallback<ActivityResult> activityResultCallback;

private ActivityLauncher(@NonNull ActivityResultCaller caller,
                         @NonNull ActivityResultContract<Intent, ActivityResult> contract,
                         @Nullable ActivityResultCallback<ActivityResult> activityResultCallback) {
    this.activityResultCallback = activityResultCallback;
    this.launcher = caller.registerForActivityResult(contract, this::onActivityResult);
}

public static ActivityLauncher registerActivityForResult(
        @NonNull ActivityResultCaller caller) {
    return new ActivityLauncher(caller, new ActivityResultContracts.StartActivityForResult(), null);
}

public void launch(Intent intent, @Nullable ActivityResultCallback<ActivityResult> activityResultCallback) {
    if (activityResultCallback != null) {
        this.activityResultCallback = activityResultCallback;
    }
    launcher.launch(intent);
}

private void onActivityResult(ActivityResult result) {
    if (activityResultCallback != null) activityResultCallback.onActivityResult(result);
}

public interface OnActivityResult {
    void onActivityResultCallback(int requestCode, int resultCode, Intent data);
}

}

在BaseActivity.java中代码

private final ActivityLauncher activityLauncher = ActivityLauncher.registerActivityForResult(this);

public void startActivityForResult(Intent intent, int requestCode, ActivityLauncher.OnActivityResult onActivityResult) {
    activityLauncher.launch(intent, result -> onActivityResult.onActivityResultCallback(requestCode, result.getResultCode(), result.getData()));
}

最后在每个扩展BaseActivity的Activity中，实现ActivityLauncher。将覆盖函数“OnActivityResult”的名称改为“onActivityResultCallback”。还记得删除super.onActivityResult()

如何使用:startActivityForResult(intent, requestCode, this)

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
        }
    }

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!：）

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
        }
    }
}

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)
            }
        }
    }

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。