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
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)
其他回答
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。
参考:Kotlin -从图库中选择图像
迄今为止我发现的最简单的Alernative
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.id.activity_main)
var ivPhoto = findViewById<ImageView>(R.id.ivPhoto)
var btnChoosePhoto = findViewById<Button>(R.id.btnChoosePhoto)
val getContent = registerForActivityResult(ActivityResultContracts.GetContent()) { uri: Uri? ->
ivPhoto.setImageURI(uri) // Handle the returned Uri
}
btnChoose.setOnClickListener {
getContent.launch("image/*")
}
}
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)
}
dor506回答为我工作,因为我在我的大多数项目中使用BaseActivity,所以对我来说更容易在单个文件中更改代码,而不是我所有的活动。我已经写了这个代码的java版本。
BaseActivity代码:
private int requestCode = -1;
private ActivityResultLauncher<Intent> resultHandler = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mContext = this;
registerForActivityResult();
}
private final void registerForActivityResult() {
if (shouldRegisterForActivityResult()) {
this.resultHandler = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(),
new ActivityResultCallback() {
public void onActivityResult(Object var1) {
this.onActivityResult((ActivityResult)var1);
}
public final void onActivityResult(ActivityResult result) {
Intrinsics.checkNotNullExpressionValue(result, "result");
AppActivityClass.onActivityResult(result.getData(), AppActivityClass.this.requestCode, result.getResultCode());
AppActivityClass.this.requestCode = -1;
}
});
}
}
public final void startActivityForResult(int requestCode, Intent intent) {
this.requestCode = requestCode;
if (resultHandler != null) {
resultHandler.launch(intent);
}
}
protected static void onActivityResult(Intent intent, int requestCode, int resultCode) {
}
protected Boolean shouldRegisterForActivityResult() {
return false;
}
现在在任何活动中使用这样的代码:
@Override
protected Boolean shouldRegisterForActivityResult() {
return true; // this will override the baseactivity method and we can use onactivityresult
}
private void someMethod(){
Intent i = new Intent(mContext,SomeOtherClassActivity.class);
startActivityForResult(101,i);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 101) {
if (resultCode == RESULT_OK) {
//revert from called class
}
}
}
从现在开始,startActivityForResult()已经被弃用,所以使用new方法代替。
芬兰湾的科特林的例子
fun openActivityForResult() {
startForResult.launch(Intent(this, AnotherActivity::class.java))
}
val startForResult = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) {
result: ActivityResult ->
if (result.resultCode == Activity.RESULT_OK) {
val intent = result.data
// Handle the Intent
//do stuff here
}
}