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
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。
其他回答
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
ActivityResultLauncher<Intent> someActivityResultLauncher = registerForActivityResult(
new ActivityResultContracts.StartActivityForResult(),
new ActivityResultCallback<ActivityResult>() {
@Override
public void onActivityResult(ActivityResult result) {
if (result.getResultCode() == Activity.RESULT_OK) {
}
}
});
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。
您可以为Koltin使用扩展函数。例如:
//random utils file
fun Fragment.buildGetContentRequest(function: (Uri) -> Unit): ActivityResultLauncher<String> {
return this.registerForActivityResult(ActivityResultContracts.GetContent()) {
function(it)
}
}
fun Fragment.buildTakePhotoRequest(function: (Boolean) -> Unit): ActivityResultLauncher<Uri> {
return this.registerForActivityResult(ActivityResultContracts.TakePicture()) {
function(it)
}
}
fun Fragment.buildSelectMultipleContentRequest(function: (MutableList<Uri>?) -> Unit): ActivityResultLauncher<String> {
return this.registerForActivityResult(ActivityResultContracts.GetMultipleContents()) {
function(it)
}
}
然后在你的片段中像这样
//your actual fragment logic
class YourFragment : Fragment() {
//we can assign our request in init process
private val mRequestSelectFiles = buildSelectMultipleContentRequest {
onFilesSelected(it)
}
fun onSelectFiles() {
val mime = "*/*"
mRequestSelectFiles.launch(mime)
}
fun onFilesSelected(list: MutableList<Uri>?) {
//your logic
}
}
onActivityResult, startActivityForResult, requestPermissions和onRequestPermissionsResult从1.3.0-alpha04开始在androidx.fragment上被弃用，android.app.Activity上没有。 相反，你可以使用registerForActivityResult的活动结果api。
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