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
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);
}
});
}
}
其他回答
以下是我的解决方案:
在我们的项目中，我们有超过20次的startActivityForResult(和onActivityResult)。
我们希望尽可能少地更改代码(并继续使用请求代码)，同时引入一个优雅的解决方案以供将来使用。
既然我们很多开发人员都使用BaseActivity概念——为什么不利用它呢?
下面是BaseActivity:
abstract class BaseActivity : AppCompatActivity()
{
private var requestCode: Int = -1
private var resultHandler: ActivityResultLauncher<Intent>? = null
override fun onCreate(savedInstanceState: Bundle?)
{
super.onCreate(savedInstanceState)
registerForActivityResult()
}
private fun registerForActivityResult()
{
if (shouldRegisterForActivityResult())
{
resultHandler = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
onActivityResult(result.data, requestCode, result.resultCode)
this.requestCode = -1
}
}
}
fun startActivityForResult(requestCode: Int, intent: Intent)
{
this.requestCode = requestCode
resultHandler?.launch(intent)
}
protected open fun onActivityResult(data: Intent?, requestCode: Int, resultCode: Int)
{
// For sub activities
}
protected open fun shouldRegisterForActivityResult(): Boolean
{
// Sub activities that need the onActivityResult "mechanism", should override this and return true
return false
}
}
这是SubActivity:
class SubActivity : BaseActivity()
{
companion object
{
private const val SOME_REQUEST_CODE = 300
}
private fun testActivityResult()
{
val intent = Intent(this, OtherActivity::class.java)
startActivityForResult(SOME_REQUEST_CODE, intent)
}
override fun shouldRegisterForActivityResult(): Boolean
{
return true
}
override fun onActivityResult(data: Intent?, requestCode: Int, resultCode: Int)
{
if (requestCode == SOME_REQUEST_CODE)
{
// Yes!
}
}
}
希望它能帮助到别人
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
}
}
我使用kotlin扩展，使它非常简单。在你的扩展中添加以下扩展功能。kt文件:
fun AppCompatActivity.startForResult(intent: Intent,
onResult: (resultCode: Int, data: Intent?) -> Unit
) {
this.registerForActivityResult(ActivityResultContracts.StartActivityForResult()) {result ->
onResult(result.resultCode, result.data)
}.launch(intent)
}
现在，在继承AppCompatActivity的任何活动中，你可以使用下面的简单代码:
val i = Intent(this, TargetActivity::class.java)
startForResult(i) { resultCode, data ->
//put your code here like:
if (resultCode == RESULT_OK) {
//your code here...
}
}
}
更新 上述实现可能导致以下异常: java.lang.IllegalStateException: LifecycleOwner xxxx正在尝试注册，而当前状态为恢复。生命周期所有者必须在启动之前调用寄存器。
因此，registerForActivityResult应该提前调用，例如在onCreate之前。这是另一种解决方案。
在你的扩展中添加以下扩展功能。kt文件:
fun AppCompatActivity.registerForResult(onResult: (resultCode: Int, data: Intent?) -> Unit):
ActivityResultLauncher<Intent> {
return this.registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
onResult(result.resultCode, result.data)
}
}
现在，在继承AppCompatActivity的任何活动中，你可以使用下面的简单代码:
为每个需要结果的操作定义一个类成员变量
private val myActionResult = registerForResult { resultCode, data ->
//put your code here like:
if (resultCode == RESULT_OK) {
//your code here...
}
}
}
启动动作
val i = Intent(this, TargetActivity::class.java)
myActionResult.launch(i)
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/*")
}
}
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);
}
});
}
}
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