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
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)
其他回答
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。
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
在我的情况下,我试图使用意图,我直接移动到下一个活动,而不使用谷歌登录。
对我有用的是:
在OnCreate中为登录按钮设置onClickListener:
btnSignIn.setOnClickListener {
signIn()
}
private fun signIn() {
val intent = client.signInIntent
mainActivityResultLauncher.launch(intent)
}
在上面的代码中,我写了去下一个活动的意图,但我必须写client.signInIntent
var mainActivityResultLauncher = registerForActivityResult(ActivityResultContracts.StartActivityForResult()){ result ->
if(result.resultCode == Activity.RESULT_OK){
val data = result.data
val task = GoogleSignIn.getSignedInAccountFromIntent(data)
try {
// Google Sign In was successful, authenticate with Firebase
val account = task.getResult(ApiException::class.java)!!
Log.d(TAG, "firebaseAuthWithGoogle:" + account.id)
firebaseAuthWithGoogle(account.idToken!!)
} catch (e: ApiException) {
// Google Sign In failed, update UI appropriately
Log.w(TAG, "Google sign in failed", e)
}
}
}
我想出了如何从Kotlin的片段中正确地做到这一点,以捕获图像并处理返回的位图。在其他情况下也是一样的。
首先,您必须注册片段以侦听活动结果。这必须在初始化片段之前完成,这意味着创建一个成员变量,而不是在onCreate函数中初始化。
class DummyFragment : Fragment() {
//registering fragment for camera listener
private val takePhoto = registerForActivityResult(
ActivityResultContracts.StartActivityForResult()
) {
if (it.resultCode == Activity.RESULT_OK) {
val imageBitmap = it.data?.extras?.get("data") as Bitmap
// do your thing with the obtained bitmap
}
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
}
}
然后,像你通常做的那样调用摄像机意图。并使用上面创建的变量来启动意图。
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
someRandomButton.setOnClickListener {
val takePictureIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
takePhoto.launch(takePictureIntent)
}
}
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)