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
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。
其他回答
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)
}
}
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
}
}
}
在替换已弃用的方法startActivityForResult(…)时,需要遵循4个简单的步骤。
In place of overridden method onActivityResult(..) - ActivityResultLauncher<Intent> activityResultLaunch = registerForActivityResult( new ActivityResultContracts.StartActivityForResult(), new ActivityResultCallback<ActivityResult>() { @Override public void onActivityResult(ActivityResult result) { if (result.getResultCode() == 123) { // ToDo : Do your stuff... } else if(result.getResultCode() == 321) { // ToDo : Do your stuff... } } });
对于多个自定义请求,将条件附加为
if (result.getResultCode() == 123) {
..
} else if(result.getResultCode() == 131){
..
} // so on..
Imports : import androidx.activity.result.ActivityResult; import androidx.activity.result.ActivityResultCallback; import androidx.activity.result.ActivityResultLauncher; import androidx.activity.result.contract.ActivityResultContracts; In place of startActivityForResult(intent, 123), use Intent intent = new Intent(this, SampleActivity.class); activityResultLaunch.launch(intent); In SampleActivity.java class, while returning back to source activity, code will remain the same like - Intent intent = new Intent(); setResult(123, intent); finish();
编码快乐!:)
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
}
}