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?
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
在芬兰湾的科特林 我改变了我的代码
startActivityForResult(intent, Constants.MY_CODE_REQUEST)
and
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent) {
super.onActivityResult(requestCode, resultCode, data)
if (resultCode == Activity.RESULT_OK) {
when (requestCode) {
Constants.MY_CODE_REQUEST -> {
...
}
to
registerForActivityResult(StartActivityForResult()) { result ->
onActivityResult(Constants.MY_CODE_REQUEST, result)
}.launch(intent)
and
private fun onActivityResult(requestCode: Int, result: ActivityResult) {
if(result.resultCode == Activity.RESULT_OK) {
val intent = result.data
when (requestCode) {
Constants.MY_CODE_REQUEST -> {
...
我希望这对你有用。: D
其他回答
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)
下面我来解释一下这种新方法
private val scan =
registerForActivityResult(ActivityResultContracts.StartActivityForResult())
{ result: ActivityResult ->
if (result.resultCode == AppCompatActivity.RESULT_OK && result.data != null) {
var selected_hub = result!!.data!!.getParcelableExtra<ExtendedBluetoothDevice>(Utils.EXTRA_DEVICE)
Log.d(TAG,"RECONNECT PROCESS "+selected_hub!!.name)
reconnect(selected_hub!!)
}
}
从活动或片段调用此方法
private fun callScan() {
val intent = Intent(requireActivity(), ScanningMeshDevices::class.java)
scan.launch(intent)
}
我的目标是用最少的代码更改重用startActivityForResult方法的当前实现。为此,我使用onActivityResultFromLauncher方法创建了一个包装器类和接口。
interface ActivityResultLauncherWrapper {
fun launchIntentForResult(activity: FragmentActivity, intent: Intent, requestCode: Int, callBack: OnActivityResultListener)
fun unregister()
interface OnActivityResultListener {
fun onActivityResultFromLauncher(requestCode: Int, resultCode: Int, data: Intent?)
}
}
class ActivityResultLauncherWrapperImpl : ActivityResultLauncherWrapper {
private var weakLauncher: WeakReference<ActivityResultLauncher<Intent>>? = null
override fun launchIntentForResult(
activity: FragmentActivity,
intent: Intent,
requestCode: Int,
callBack: ActivityResultLauncherWrapper.OnActivityResultListener
) {
weakLauncher = WeakReference(
activity.registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
callBack.onActivityResultFromLauncher(requestCode, result.resultCode, result.data)
}
)
weakLauncher?.get()?.launch(intent)
}
override fun unregister() {
weakLauncher?.get()?.unregister()
}
}
我在我的项目中使用匕首,我在需要的地方注入了包装器
@Inject
lateinit var activityResultLauncher: ActivityResultLauncherWrapper
但是包装器也可以直接实例化:
val activityResultLauncher = ActivityResultLauncherWrapper()
然后你必须用launchIntentForResult改变startActivityForResult方法。下面是一个从片段中调用它的例子:
activityResultLauncher.launchIntentForResult(
requireActivity(),
intent,
REQUEST_CODE_CONSTANT,
object: ActivityResultLauncherWrapper.OnActivityResultListener {
override fun onActivityResultFromLauncher(requestCode: Int, resultCode: Int, data: Intent?) {
/*do something*/
}
}
)
您将在匿名对象中收到结果。 你可以在Fragment或FragmentActivity中使用OnActivityResultListener,如果你实现了接口,并像这样重构当前的实现:
class MyFragment : Fragment(), OnActivityResultListener {
...
override fun onActivityResultFromLauncher(requestCode: Int, resultCode: Int, data: Intent?) {/*do somthing*/}
...
}
正如我们所知,Kotlin类ActivityResultLauncherWrapper也可以在java代码中使用。在我的项目中也有java类。这里有一个在Fragment中实现回调接口的例子:
public class MyFragment extends Fragment implements OnActivityResultListener {
...
@Inject
ActivityResultLauncherWrapper activityResultLauncher;
//ActivityResultLauncherWrapper activityResultLauncher = new ActivityResultLauncherWrapper()
...
public void launnchActivity(@NotNull Intent intent) {
activityResultLauncher.launchIntentForResult(requireActivity(), intent, REQUEST_CODE_CONSTANT, this);
}
...
@Override
public void onActivityResultFromLauncher(int requestCode, int resultCode, Intent data) {/*do somthing*/}
...
}
我希望这有助于为您的案例构建解决方案。
你可以在developer.android.com上获得基本的培训。
下面是一个关于如何将现有代码转换为新代码的示例:
老办法:
public void openSomeActivityForResult() {
Intent intent = new Intent(this, SomeActivity.class);
startActivityForResult(intent, 123);
}
@Override
protected void onActivityResult (int requestCode, int resultCode, Intent data) {
if (resultCode == Activity.RESULT_OK && requestCode == 123) {
doSomeOperations();
}
}
新方法(Java):
public void openSomeActivityForResult() {
Intent intent = new Intent(this, SomeActivity.class);
someActivityResultLauncher.launch(intent);
}
// You can do the assignment inside onAttach or onCreate, i.e, before the activity is displayed
ActivityResultLauncher<Intent> someActivityResultLauncher = registerForActivityResult(
new ActivityResultContracts.StartActivityForResult(),
new ActivityResultCallback<ActivityResult>() {
@Override
public void onActivityResult(ActivityResult result) {
if (result.getResultCode() == Activity.RESULT_OK) {
// There are no request codes
Intent data = result.getData();
doSomeOperations();
}
}
});
新方法(Kotlin):
fun openSomeActivityForResult() {
val intent = Intent(this, SomeActivity::class.java)
resultLauncher.launch(intent)
}
var resultLauncher = registerForActivityResult(StartActivityForResult()) { result ->
if (result.resultCode == Activity.RESULT_OK) {
// There are no request codes
val data: Intent? = result.data
doSomeOperations()
}
}
编辑。一个更好的方法是使它更一般化,这样我们就可以重用它。下面的代码片段用于我的一个项目,但请注意,它没有经过良好的测试,可能无法涵盖所有情况。
BetterActivityResult.java
import android.content.Intent;
import androidx.activity.result.ActivityResult;
import androidx.activity.result.ActivityResultCaller;
import androidx.activity.result.ActivityResultLauncher;
import androidx.activity.result.contract.ActivityResultContract;
import androidx.activity.result.contract.ActivityResultContracts;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
public class BetterActivityResult<Input, Result> {
/**
* Register activity result using a {@link ActivityResultContract} and an in-place activity result callback like
* the default approach. You can still customise callback using {@link #launch(Object, OnActivityResult)}.
*/
@NonNull
public static <Input, Result> BetterActivityResult<Input, Result> registerForActivityResult(
@NonNull ActivityResultCaller caller,
@NonNull ActivityResultContract<Input, Result> contract,
@Nullable OnActivityResult<Result> onActivityResult) {
return new BetterActivityResult<>(caller, contract, onActivityResult);
}
/**
* Same as {@link #registerForActivityResult(ActivityResultCaller, ActivityResultContract, OnActivityResult)} except
* the last argument is set to {@code null}.
*/
@NonNull
public static <Input, Result> BetterActivityResult<Input, Result> registerForActivityResult(
@NonNull ActivityResultCaller caller,
@NonNull ActivityResultContract<Input, Result> contract) {
return registerForActivityResult(caller, contract, null);
}
/**
* Specialised method for launching new activities.
*/
@NonNull
public static BetterActivityResult<Intent, ActivityResult> registerActivityForResult(
@NonNull ActivityResultCaller caller) {
return registerForActivityResult(caller, new ActivityResultContracts.StartActivityForResult());
}
/**
* Callback interface
*/
public interface OnActivityResult<O> {
/**
* Called after receiving a result from the target activity
*/
void onActivityResult(O result);
}
private final ActivityResultLauncher<Input> launcher;
@Nullable
private OnActivityResult<Result> onActivityResult;
private BetterActivityResult(@NonNull ActivityResultCaller caller,
@NonNull ActivityResultContract<Input, Result> contract,
@Nullable OnActivityResult<Result> onActivityResult) {
this.onActivityResult = onActivityResult;
this.launcher = caller.registerForActivityResult(contract, this::callOnActivityResult);
}
public void setOnActivityResult(@Nullable OnActivityResult<Result> onActivityResult) {
this.onActivityResult = onActivityResult;
}
/**
* Launch activity, same as {@link ActivityResultLauncher#launch(Object)} except that it allows a callback
* executed after receiving a result from the target activity.
*/
public void launch(Input input, @Nullable OnActivityResult<Result> onActivityResult) {
if (onActivityResult != null) {
this.onActivityResult = onActivityResult;
}
launcher.launch(input);
}
/**
* Same as {@link #launch(Object, OnActivityResult)} with last parameter set to {@code null}.
*/
public void launch(Input input) {
launch(input, this.onActivityResult);
}
private void callOnActivityResult(Result result) {
if (onActivityResult != null) onActivityResult.onActivityResult(result);
}
}
使用上述方法,您仍然必须在启动活动或片段附件之前或期间注册它。一旦定义,就可以在活动或片段中重用它。例如,如果你需要在大部分活动中启动新的活动,你可以定义一个BaseActivity并像这样注册一个新的BetterActivityResult:
BaseActivity.java
public class BaseActivity extends AppCompatActivity {
protected final BetterActivityResult<Intent, ActivityResult> activityLauncher = BetterActivityResult.registerActivityForResult(this);
}
之后,你可以简单地从任何子活动中启动一个活动,就像这样:
public void openSomeActivityForResult() {
Intent intent = new Intent(this, SomeActivity.class);
activityLauncher.launch(intent, result -> {
if (result.getResultCode() == Activity.RESULT_OK) {
// There are no request codes
Intent data = result.getData();
doSomeOperations();
}
})
}
因为你可以在Intent的同时设置回调函数,所以你可以在任何活动中重用它。
类似地,您也可以使用其他两个构造函数来使用其他活动契约。
添加到muntashir akon和abhijeet的答案,你可以通过在意图中传递值来修改新格式,使其像旧格式一样工作,例如:
// calling class
....
val i = Intent(this@GEBShopActivity, BarcodeScannerActivity::class.java)
when(loadedFragment){
is ShopHomeFragment -> { i.putExtra("myapp.result.code", CODE_ACTIVITY_SCAN_LIST_MAINT) }
is ShopListFragment -> { i.putExtra("myapp.result.code", CODE_ACTIVITY_SCAN_LIST_MAINT) }
is ShopItemMaintFragment -> { i.putExtra("myapp.result.code", CODE_ACTIVITY_SCAN_ITEM_MAINT) }
is ShopPriceFragment -> { i.putExtra("myapp.result.code", CODE_ACTIVITY_PRICE_CAPTURE) }
is ShopCompareFragment -> { i.putExtra("myapp.result.code", CODE_ACTIVITY_PRICE_CAPTURE) }
}
shopFragmentLauncher.launch(i)
....
// called class
....
val resultIntent = Intent()
val bundle = Bundle()
bundle.putStringArrayList("scanned_barcodes", scanned_barcodes)
bundle.putInt("scan_count", scan_count)
resultIntent.putExtras(bundle)
resultIntent.putExtra("myapp.result.code", intent.getIntExtra("myapp.result.code", 0))
setResult(Activity.RESULT_OK, resultIntent)
....
这将允许您保持类的调用相同,只需要额外的一行来添加原始调用的结果代码。还允许您创建一个可重用的启动程序实例。