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

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)

其他回答

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())
  }
 }
}

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.

另一种方法是分3步完成。(考虑到你有一个startActivityForResult(0和onActivityResult()))

创建一个形式为var resultLauncher的变量:ActivityResultLauncher<Intent> 创建一个私有函数,在其中以这种基本格式初始化resultLauncher

resultLauncher=registerForActivityResult(ActivityResultContracts.StartActivityForResult()){result ->  

// copy paste the code from the onActivityResult replacing resultcode to result.resultCode  

if(result.resultcode==Activity.Result_OK){
val data=result.data // this data variable is of type intent and you can use it 

}else{
//code if you do not get the data 
}
}

使用startActivityForResult()返回行,并将其替换为resultLauncher.launch(intent)

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

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)