小编Sau*_*rat的帖子

设备：模拟器像素 3a - Android 11

代码：

    final List<Intent> cameraIntents = new ArrayList<Intent>();
    final Intent captureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    final List<ResolveInfo> listCam = 
    context.getPackageManager().queryIntentActivities(captureIntent, 0);

使用时：

targetSdkVersion 30
compileSdkVersion 30

listCam 大小为 0

当更改为：

compileSdkVersion 29

listCam 大小为 1 - 应该如此。

使用以下代码：

    val captureIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
    baseActivity.startActivity(captureIntent)

工作正常并显示相机应用程序。

知道为什么 queryIntentActivities 不返回相机意图吗？

谢谢！

我正在使用Paging库来分页我正从服务器检索的项目列表.最初,当我的片段被加载时,它返回一个空列表.但是在更改片段并返回到该片段后,我可以看到列表已加载.调试后,我看到实际上正在获取数据,但是一个空列表被传递给我的片段.

ItemDataSource:

@Override
public void loadInitial(@NonNull LoadInitialParams<Integer> params, @NonNull LoadInitialCallback<Integer, Item> callback) {
    apiService.getItems(OFFSET)
    .enqueue(new Callback<ItemWrapper>() {
        @Override
        public void onResponse(@NonNull Call<ItemWrapper> call,@NonNull Response<ItemWrapper> response) {
            callback.onResult(response.body().getItems(), null, OFFSET + 25);
        }

        @Override
        public void onFailure(@NonNull Call<ItemWrapper> call,@NonNull Throwable t) {
            t.printStackTrace();
        }
    });
}

@Override
public void loadBefore(@NonNull LoadParams<Integer> params, @NonNull LoadCallback<Integer, Item> callback) {

}

@Override
public void loadAfter(@NonNull LoadParams<Integer> params, @NonNull LoadCallback<Integer, Item> callback) {
    apiService.getItems(params.key)
            .enqueue(new Callback<ItemWrapper>() {
                @Override
                public void onResponse(@NonNull Call<ItemWrapper> call,@NonNull Response<ItemWrapper> response) …

我运行react-native 0.57.1​​应用程序,然后我得到以下行.

FAILURE: Build failed with an exception.
* What went wrong:
Could not resolve all files for configuration ':app:debugCompileClasspath'.
/> Could not find support-vector-drawable.aar (com.android.support:support-vector-drawable:27.1.1).
  Searched in the following locations:
      https://jcenter.bintray.com/com/android/support/support-vector-drawable/27.1.1/support-vector-drawable-27.1.1.aar
/> Could not find livedata-core.aar (android.arch.lifecycle:livedata-core:1.1.0).
  Searched in the following locations:
      https://jcenter.bintray.com/android/arch/lifecycle/livedata-core/1.1.0/livedata-core-1.1.0.aar
/> Could not find viewmodel.aar (android.arch.lifecycle:viewmodel:1.1.0).
  Searched in the following locations:
      https://jcenter.bintray.com/android/arch/lifecycle/viewmodel/1.1.0/viewmodel-1.1.0.aar
/> Could not find runtime.aar (android.arch.core:runtime:1.1.0).
  Searched in the following locations:
      https://jcenter.bintray.com/android/arch/core/runtime/1.1.0/runtime-1.1.0.aar

有什么建议？Thx提前

我已经为 CameraX kotlin 更新了我的 gradle 插件，突然间我遇到了一个我不知道如何修复的错误。

这是我的相机片段

    package com.khumomashapa.notes.fragments

import android.annotation.SuppressLint
import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.content.IntentFilter
import android.content.res.Configuration
import android.graphics.Color
import android.graphics.drawable.ColorDrawable
import android.hardware.display.DisplayManager
import android.media.MediaScannerConnection
import android.net.Uri
import android.os.Build
import android.os.Bundle
import android.util.DisplayMetrics
import android.util.Log
import android.view.KeyEvent
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.webkit.MimeTypeMap
import android.widget.ImageButton
import androidx.camera.core.AspectRatio
import androidx.camera.core.Camera
import androidx.camera.core.CameraInfoUnavailableException
import androidx.camera.core.CameraSelector
import androidx.camera.core.ImageAnalysis
import androidx.camera.core.ImageCapture
import androidx.camera.core.ImageCapture.Metadata
import androidx.camera.core.ImageCaptureException
import androidx.camera.core.ImageProxy
import androidx.camera.core.Preview
import androidx.camera.lifecycle.ProcessCameraProvider
import androidx.camera.view.PreviewView
import androidx.constraintlayout.widget.ConstraintLayout
import androidx.core.content.ContextCompat
import …

得到错误

无法为 com.android.build.gradle.internal.api.ApplicationVariantImpl 类型的对象设置未知属性“outputFileName”。

使用安卓工作室 3.2.1

4.6 级

applicationVariants.all { variant ->
             variant.outputs.each { output ->
                 def fileName = "${project.name}_${output.baseName}-${variant.versionName}.apk"
                 outputFileName = new File(output.outputFile.parent, fileName).getName()
             }
         }

我正在使用LiveData从服务器获取数据并进行观察。我的onChanged()方法只是在第一次调用，而在服务器中的数据更新时不会调用。

用户片段：

UserViewModel userViewModel = ViewModelProviders.of(this).get(UserViewModel.class);
userViewModel.getUser().observe(this, new Observer<User>() {
    @Override
    public void onChanged(User user) {
        //Set UI
    }
});

UserViewModel：

public class UserViewModel extends AndroidViewModel {
    private LiveData<User> user;

    public UserViewModel(Application application) {
        super(application);
        user = UserRepository.getInstance().fetchUser();
    }

    public LiveData<User> getUser() {
        return user;
    }    
}

UserRepository：

public class UserRepository {    
    private ApiService apiService;
    private static UserRepository userRepository;

    private UserRepository() {
        apiService = RestClient.getClient().create(ApiService.class);
    }

    public synchronized static UserRepository getInstance() {
        if (userRepository == null) userRepository = …