小编Jas*_*Jas的帖子

我正在开发一个增强现实应用程序,其中我有一个摄像头预览屏幕,我在其上绘制了一些相对于设备移动而移动的标记.

当我lock and unlock在设备上时,标记会冻结并且不会进一步移动.我无法找到发生这种情况的原因.这有什么可行的解决办法吗？任何帮助将不胜感激.

我的SurfaceView类:

    public class CameraSurface extends SurfaceView implements SurfaceHolder.Callback
    {
    private static SurfaceHolder holder = null;
    public static Camera camera = null;
    Activity ctx;

    public CameraSurface(Activity context) {
        super(context);
        ctx=context;

        try {
            holder = getHolder();
            holder.addCallback(this);
            holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    public CameraSurface(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);

    }

    public CameraSurface(Context context, AttributeSet attrs) {
        super(context, attrs);

    }


    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        try {
            if …

我想实现流媒体视频列表应用.我用a RecyclerView来显示我的列表项.项目类型包括4种类型:文章,状态,照片和视频.我们应该只关注视频类型.这是我的RecyclerView适配器的代码:

public class FollowedPostAdapter extends RecyclerView.Adapter implements OnFollowTagCallback, OnLikeCallback {
    private Context context;
    private List<PostItem> newsFeedList;
    public RecyclerView recyclerView;
    public LinearLayoutManager linearLayoutManager;
    private HashMap<Integer, DemoPlayer> playerList;

    private int visibleThreshold = 5;
    // private int previousTotal = 0;
    private int visibleItemCount, firstVisibleItem, totalItemCount;
    private boolean loading;
    private OnRecyclerViewLoadMoreListener loadMoreListener;


    private final String text_comment;
    private final String mReadMoreHtml;
    private long userId;


    public FollowedPostAdapter(Context context, RecyclerView recyclerView, List<PostItem> newsFeedList) {
        this.context = context;
        playerList = new HashMap<>();
        this.newsFeedList = newsFeedList;
        this.recyclerView …

我有一个ViewPager ,Fragment如果某个动作发生,我必须更换第一个.

public static class PagerAdapter extends FragmentStatePagerAdapter{

    private TempChannel latestChannel;
    private VideosFragment.SortType sortType;

    public PagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        switch (position){
            case 0:
                if(latestChannel == null) {
                    return new LatestVideosFragment();
                }else{
                    return VideosFragment.getVideosFragment(latestChannel, sortType);
                }
            case 1:
                return new LiveVideosFragment();
            case 2:
                return new ConversationsFragment();
        }
        return null;
    }
}

基本上,当我单击某个通道时LatestVideosFragment,适配器中的第一个位置应该更改为VideosFragment该类的实例.

public void startLatestChannelFragment(TempChannel channel, VideosFragment.SortType sortType){
    adapter.setLatestChannel(channel, sortType);
    adapter.notifyDataSetChanged();
    Log.d("x", "on channel started");
}

我假设调用 …

我正在按照本教程ViewPager在我的项目中实现.我已成功使用静态图像.现在我想更改它,以便从网址中检索图像并显示在其中ViewPager.以下是我的代码.

我应该在哪里添加下载图像的方法以及如何将其设置为我的ViewPager？

任何帮助将不胜感激.

主要活动:

public class MainActivity extends AppCompatActivity {

    private ArrayList<Integer> images;
    private BitmapFactory.Options options;
    private ViewPager viewPager;
    private View btnNext, btnPrev;
    private FragmentStatePagerAdapter adapter;
    private LinearLayout thumbnailsContainer;
    private final static int[] resourceIDs = new int[]{R.mipmap.a, R.mipmap.b,
            R.mipmap.c, R.mipmap.d, R.mipmap.e, R.mipmap.f, R.mipmap.g};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        images = new ArrayList<>();

        //find view by id
        viewPager = (ViewPager) findViewById(R.id.view_pager);
        thumbnailsContainer = (LinearLayout) findViewById(R.id.container);
        btnNext = …

我使用Picasso库在我的应用程序中加载图像.但在某些图像中,它显示了一个彩色的角落.看到附加图像中的红色.有谁知道为什么会这样？如何解决这个问题？

码:

Picasso picasso = Picasso.with(getActivity());
        picasso.setDebugging(true);
        picasso.load(downloadPath+imgDetailPhoto)
                .placeholder(R.drawable.no_image)
                .error(R.drawable.no_image)
                .into(eventImage, new Callback() {
                    @Override
                    public void onSuccess() {

                    }

                    @Override
                    public void onError() {
                        Log.d("Error...", "picasso load error");
                        Picasso.with(getActivity()).load(R.drawable.no_image).into(eventImage);
                    }
                });

我想以SeekBar编程方式在画布上绘制.我编写了代码来设置SeekBar基于设备密度的LayoutParams .我正在使用具有设备密度的开关盒

final DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
if(metrics.densityDpi <= DisplayMetrics.DENSITY_LOW){
        zoomBarParams = new LinearLayout.LayoutParams(18,
                LayoutParams.FILL_PARENT);
        } else if (metrics.densityDpi <= DisplayMetrics.DENSITY_MEDIUM){
            zoomBarParams = new LinearLayout.LayoutParams(24,
                    LayoutParams.FILL_PARENT);

        }else if (metrics.densityDpi <= DisplayMetrics.DENSITY_HIGH){
            zoomBarParams = new LinearLayout.LayoutParams(24,
                    LayoutParams.FILL_PARENT);

        }else if (metrics.densityDpi <= DisplayMetrics.DENSITY_XHIGH){
            zoomBarParams = new LinearLayout.LayoutParams(31,
                    LayoutParams.FILL_PARENT);


        }else if (metrics.densityDpi <= DisplayMetrics.DENSITY_XXHIGH){
            zoomBarParams = new LinearLayout.LayoutParams(60,
                    LayoutParams.FILL_PARENT);

        }else if (metrics.densityDpi <= DisplayMetrics.DENSITY_XXXHIGH){
            zoomBarParams = new LinearLayout.LayoutParams(60,
                    LayoutParams.FILL_PARENT);

        } else {
            zoomBarParams = new LinearLayout.LayoutParams(60,
                    LayoutParams.FILL_PARENT);

        }

但这不适用于三星Note …

如果ListView只显示5个项目,则所有数据为40个项目.如何获得当前选择的可见项目(1~5)中的哪个位置？我已经尝试 getSelectedItemPosition但它将返回所有数据中的位置.我想在每个项目上显示可见项目中的位置编号.

    class MyAdapter extends BaseAdapter {
        @Override 
        public int getCount(){
         ...
        }
        @Override 
        public Object getItem(int position){
         ...
        }
        @Override    
        public View getView(int position, View convertView, ViewGroup parent)
        {  
           // I want to get the position number in visible items here
        }
    }

我需要创建一个应用程序,我想录制视频,并在文件大小超过10 mb时停止录制.这可能吗？我知道保存后可以检查文件大小.但我想知道这是否可以在运行时完成.任何帮助将不胜感激.

我有一个RecyclerView用于显示使用内容提供程序从内容提供程序获取的数据LoaderManager.它工作正常,但我注意到加载大数据时我的下面的实现有一些性能问题,显示数据有一个滞后,因为我使用a ViewPager加载Fragment主机这个方法

@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
    Favorites = new ArrayList<>();

    if (cursor != null) {
        while (cursor.moveToNext())
            Favorites.add(FavoritesModel.fromCursor(cursor));
    }
    adapter = new FavoritesAdapter(getActivity(),Favorites);
    favoritesRecyclerView.setAdapter(adapter);
  }

所以我选择做以下事情:

 @Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
     ........
    adapter = new FavoritesAdapter(getActivity(),Favorites);
    favoritesRecyclerView.setAdapter(adapter);
    ........ 

然后在onLoadFinished上

@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
    Favorites = new ArrayList<>();

    if (cursor != null) {
        while (cursor.moveToNext())
            Favorites.add(FavoritesModel.fromCursor(cursor));
    }
    adapter.notifyDataSetChanged();

  } 

使用此功能无需显示.什么是问题,因为onLoadFinished总是被调用,我知道它始终在UI线程上调用

我想我的应用程序打开一些网址.但不是所有的.Android不允许排除网址((通过使用android:pathPattern或android:pathPrefix.

现在打开我使用的网址:

Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(PRIVACY_POLICY_URL));
        browserIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        getApplicationContext().startActivity(browserIntent);

我想只在外部浏览器中打开一些网页链接.可能吗？

我想将某些URL中的图像动态添加到线性布局中.运行该段代码时出现错误无法启动活动

ComponentInfo:位于com.example的com.example.star.example.CompampleActivity.insertPhoto(CompinfoActivity.java:50)的com.example.star.example.CompinfoActivity.getBitmapFromURL(CompinfoActivity.java:70)中的android.os.NetworkOnMainThreadException. star.example.CompinfoActivity.onCreate(CompinfoActivity.java:38)

请帮忙.这是我下面活动的代码.

public class CompinfoActivity extends AppCompatActivity {

Dialog dialog;
LinearLayout myGallery;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_compinfo);

    dialog = new Dialog(this);
    dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
    dialog.setContentView(R.layout.activity_compinfopopup);
    dialog.getWindow().getAttributes().width = AbsListView.LayoutParams.MATCH_PARENT;
    dialog.getWindow().getAttributes().height = AbsListView.LayoutParams.WRAP_CONTENT;
    dialog.show();

    myGallery = (LinearLayout) dialog.findViewById(R.id.mygallery);
    myGallery.addView(insertPhoto("http://example.com/a.png"));
    myGallery.addView(insertPhoto("http://example.com/b.png"));
    myGallery.addView(insertPhoto("http://example.com/c.png"));
    myGallery.addView(insertPhoto("http://example.com/d.png"));
    new MyTask().execute();



}

View insertPhoto(String path){
    Bitmap bm;
    bm =  getBitmapFromURL(path);
    LinearLayout layout = new LinearLayout(getApplicationContext());
    layout.setLayoutParams(new AbsListView.LayoutParams(250, 250));
    layout.setGravity(Gravity.CENTER);

    ImageView imageView = new ImageView(getApplicationContext());
    imageView.setLayoutParams(new AbsListView.LayoutParams(220, 220));
    imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
    imageView.setImageBitmap(bm);

    layout.addView(imageView);
    return layout;
}


public static Bitmap …

我在Android项目中使用以下代码下载文件:

URL url = new URL(fileUrl);
URLConnection conection= url.openConnection();
conection.setDoOutput(true);
conection.connect();
int lenghtOfFile = conection.getContentLength();

如果fileUrl是apk,则lenghtOfFile始终返回-1.
但如果是图像,视频类型,... lenghtOfFile返回正好.

为什么？

我正在使用eclipse,Android SDK修订版23.

我想将另一个类的数据添加到我的数据库中,我得到这个错误:

"SQLiteLog:(1)接近"Produse":语法错误"和"SQLiteDatabase:错误插入高级成衣= 102.0 Ingrediente =成分1;成分2;成分3;组分4;成分5; Nume Produse = Produsul 15波萨= poza15.jpg Gramaj = 195.0
android.database.sqlite.SQLiteException:邻近"Produse":语法错误(码1):在编译:INSERT INTO Produse(高级成衣,Ingrediente,Nume Produse,波萨,Gramaj)VALUES(,,,？？？ ？,？)"

这是我的MyDBHandler类的代码

public class MyDBHander extends SQLiteOpenHelper{

    public static final int DATABASE_VERSION = 1;
    public static final String DATABASE_NAME = "produseDB.db";
    public static final String TABLE_PRODUCTS = "Produse";

    public static int COLUMN_ID = 0;
    public static String COLUMN_PRODUS = "Nume Produse";
    public static String COLUMN_INGREDIENTE = "Ingrediente";
    public static String COLUMN_GRAMAJ = "Gramaj";
    public static String COLUMN_PRET = "Pret";
    public static String …