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
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。
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)
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
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。
如果你像这样实现你的base Activity,你可以继续使用旧的startActivityForResult。 唯一的限制是你必须使用setResult(result, intent)在你的活动中设置结果。 关键是让结果将请求代码带回结果使用者。
public class MyBaseActivity extends AppCompatActivity {
private ActivityResultLauncher<Intent> activityLauncher;
protected static String ACTIVITY_REQUEST_CODE = "my.activity.request.code";
protected _originalIntent;
public void launchActivityForResult(Intent intent, int requestCode){
intent.putExtra(UGM_ACTIVITY_REQUEST_CODE, requestCode);
activityLauncher.launch(intent);
}
//
//In order to be signature compatible for the rest of derived activities,
//we will override the deprecated method with our own implementation!
//
@SuppressWarnings( "deprecation" )
public void startActivityForResult(Intent intent, int requestCode){
launchActivityForResult(intent, requestCode);
}
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
_originalIntent = getIntent();
//set the default result
setResult(Activity.RESULT_OK, _originalIntent);
activityLauncher = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(), new ActivityResultCallback<ActivityResult>() {
@Override
public void onActivityResult(ActivityResult result) {
Intent intent = result.getData();
int requestCode = intent.getIntExtra(ACTIVITY_REQUEST_CODE, -1);
MyBaseActivity.this.onActivityResult(requestCode, result.getResultCode(), intent);
}
});
}
}
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。