我最近发现onActivityResult已弃用。我们该怎么处理呢?

有什么替代方案吗?


当前回答

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

其他回答

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
        }
    }
}

似乎onActivityResult在超类中已弃用,但你在你的问题中没有提到超类名称和compileSdkVersion。

在Java和Kotlin中,只要添加@Deprecated,每个类或方法都可以标记为deprecated,所以检查你的超类,你可能扩展了一个错误的类。

当一个类被弃用时,它的所有方法也被弃用。

要看到一个快速的解决方案,点击弃用的方法,并按Ctrl+Q在Android工作室查看方法的文档,应该有一个解决方案。


在我使用androidx和API 29作为compileSdkVersion的项目中,此方法在活动和片段中不弃用

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

                }
            }
        });

在Java 8中,它可以这样写:

ActivityResultLauncher<Intent> startActivityForResult = registerForActivityResult(
    new ActivityResultContracts.StartActivityForResult(),
    result -> {
        if (result.getResultCode() == AppCompatActivity.RESULT_OK) {
            Intent data = result.getData();
            // ...
        }
    }
);

Intent intent = new Intent( ... );
startActivityForResult.launch(intent);