startActivityForResult替代方案

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startActivityForResult替代方案

startActivityForResult过时

替代方案：ActivityResultContract

1、如何使用

1.1 定义ActivityResultContract

//泛型    1-ActivityResultLauncher.launch调用时需要的参数类型
//泛型    2-回调ActivityResultCallback返回类型
val activityResultContract = object : ActivityResultContract<Intent, ActivityResult>() {override fun createIntent(context: Context, input: Intent): Intent {return input}
​override fun parseResult(resultCode: Int, intent: Intent?): ActivityResult {return ActivityResult(resultCode,intent)}
}

1.2 定义ActivityResultCallback

//页面返回回调
val activityResultCallback = object : ActivityResultCallback<ActivityResult> {override fun onActivityResult(result: ActivityResult?) {if (result != null && result.resultCode == RESULT_OK) {//todo}}
}

1.3 activity或者fragment中进行注册

//参数     ActivityResultContract  ActivityResultCallback
//返回值   ActivityResultLauncher
registerForActivityResult = registerForActivityResult(activityResultContract, activityResultCallback)

1.4 ActivityResultLauncher合适时机调用

//调用       
registerForActivityResult?.launch(Intent(this,DetainmentActivityActivity::class.java))

2、预置实现

2.1 调用

val registerForActivityResult=registerForActivityResult(ActivityResultContracts.StartActivityForResult(),object : ActivityResultCallback<ActivityResult> {override fun onActivityResult(result: ActivityResult?) {if (result != null && result.resultCode == RESULT_OK) {finish()}}})registerForActivityResult.launch(Intent(this,DetainmentActivityActivity::class.java))

2.2 StartActivityForResult代码

​
public static final class StartActivityForResultextends ActivityResultContract<Intent, ActivityResult> {
​@NonNull@Overridepublic Intent createIntent(@NonNull Context context, @NonNull Intent input) {return input;}
​@NonNull@Overridepublic ActivityResult parseResult(int resultCode, @Nullable Intent intent) {return new ActivityResult(resultCode, intent);}
}