我正在使用 RecyclerView 並且我想隨機顯示圖像

Question

我正在使用 RecyclerView 制作一個壁紙應用程序，我想知道如何進行隨機（shuffle），所以我正在尋找一種方法，但我找不到一個好的方法。 請讓我知道如何解決它。 先感謝您。

我分享我正在使用的來源。 我不是專業的開發者，但我是一個把應用作為一種愛好的人，所以我還缺乏很多。 對不起，謝謝。

主要活動

public class MainActivity extends AppCompatActivity {
FloatingActionButton option_01;
FloatingActionButton option_02;
FloatingActionButton option_03;
FloatingActionButton option_04;
static final int PERMISSIONS_REQUEST = 0x0000001;
//종료팝업 전면광고 추가
private static final String TAG = "ted";
TedAdmobDialog nativeTedAdmobDialog;

private AdView mAdView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    MobileAds.initialize(this, getString(R.string.admob_app_id));
    mAdView = findViewById(R.id.adView);
    AdRequest adRequest = new AdRequest.Builder().build();
    mAdView.loadAd(adRequest);
    checkPermission();




    RecyclerView.LayoutManager layoutManager = new GridLayoutManager(this, 2);
    RecyclerView recyclerView = findViewById(R.id.rv_images);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(layoutManager);
    recyclerView.addItemDecoration(new SpacesItemDecoration());

    ImageGalleryAdapter adapter = new ImageGalleryAdapter(this, WallPhoto.getWallPhotos());
    recyclerView.setAdapter(adapter);
    adapter.notifyDataSetChanged();


    option_01 = findViewById(R.id.option_01);
    option_01.setOnClickListener(v -> {
        Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=" + getPackageName()));
        startActivity(intent);
    });

    option_02 = findViewById(R.id.option_02);
    option_02.setOnClickListener(v -> {
        Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/developer?id=Project+J+Lab"));
        startActivity(intent);
    });

    option_03 = findViewById(R.id.option_03);
    option_03.setOnClickListener(v -> {
        Intent myintent = new Intent(Intent.ACTION_SEND);
        myintent.setType("text/plan");

        String shereBoday = "Your Boday Here";

        String shereSub = "\"http://play.google.com/store/apps/details?id=" + getPackageName();
        myintent.putExtra(Intent.EXTRA_SUBJECT, shereBoday);
        myintent.putExtra(Intent.EXTRA_TEXT, shereSub);
        startActivity(Intent.createChooser(myintent, "shere Using"));
    });

    option_04 = findViewById(R.id.option_04);
    option_04.setOnClickListener(v -> {
        Intent email = new Intent(Intent.ACTION_SEND);
        email.setType("plain/text");
        String[] address = {"dhsthdwjd1@gmail.com"};
        email.putExtra(Intent.EXTRA_EMAIL, address);
        email.putExtra(Intent.EXTRA_SUBJECT, getPackageName());
        email.putExtra(Intent.EXTRA_TEXT, "text");
        startActivity(email);
    });
}

@Override
public void onBackPressed() {
    //종료팝업 전면광고 추가
    nativeTedAdmobDialog = new TedAdmobDialog.Builder(MainActivity.this, TedAdmobDialog.AdType.NATIVE, getString(R.string.banner_ad_unit_id_native))
            .setOnBackPressListener(new OnBackPressListener() {
                @Override
                public void onReviewClick() {

                }

                @Override
                public void onFinish() {
                    finish();
                }

                @Override
                public void onAdShow() {
                    log("onAdShow");
                    nativeTedAdmobDialog.loadNative();
                }
            })
            .create();
    nativeTedAdmobDialog.show();

}

//종료팝업 전면광고 추가
private void log(String text) {
    Log.d(TAG, text);
}

class ImageGalleryAdapter extends RecyclerView.Adapter<ImageGalleryAdapter.MyViewHolder> {

    private WallPhoto[] mWallPhotos;
    private Context mContext;

    public ImageGalleryAdapter(Context context, WallPhoto[] WallPhotos) {
        mContext = context;
        mWallPhotos = WallPhotos;
    }

    @Override
    public ImageGalleryAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        Context context = parent.getContext();
        LayoutInflater inflater = LayoutInflater.from(context);
        View photoView = inflater.inflate(R.layout.item_photo, parent, false);
        ImageGalleryAdapter.MyViewHolder viewHolder = new ImageGalleryAdapter.MyViewHolder(photoView);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(ImageGalleryAdapter.MyViewHolder holder, int position) {
        WallPhoto WallPhoto = mWallPhotos[position];
        ImageView imageView = holder.mPhotoImageView;

        Picasso.get()
                .load(WallPhoto.getUrl())
                .resize(200, 320)
                .centerCrop()
                .into(imageView);
    }

    @Override
    public int getItemCount() {
        return (mWallPhotos.length);
    }

    public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

        public ImageView mPhotoImageView;

        public MyViewHolder(View itemView) {

            super(itemView);
            mPhotoImageView = itemView.findViewById(R.id.iv_photo);
            itemView.setOnClickListener(this);

        }

        @Override
        public void onClick(View view) {

            int position = getAdapterPosition();
            if (position != RecyclerView.NO_POSITION) {
                WallPhoto WallPhoto = mWallPhotos[position];
                Intent intent = new Intent(mContext, DetailActivity.class);
                intent.putExtra(DetailActivity.EXTRA_TRAVEL_PHOTO, WallPhoto);
                startActivity(intent);
            }
        }


    }


}

private void checkPermission() {
    PermissionListener permissionlistener = new PermissionListener() {
        @Override
        public void onPermissionGranted() {
        }

        @Override
        public void onPermissionDenied(List<String> deniedPermissions) {
        }
    };

    TedPermission.with(this)
            .setPermissionListener(permissionlistener)
            .setPermissions(
                    Manifest.permission.SET_WALLPAPER,
                    Manifest.permission.WRITE_EXTERNAL_STORAGE,
                    Manifest.permission.READ_PHONE_STATE,
                    Manifest.permission.INTERNET,
                    Manifest.permission.ACCESS_COARSE_LOCATION,
                    Manifest.permission.ACCESS_FINE_LOCATION)
            .check();
}

}

牆圖

public class WallPhoto implements Parcelable {

public static final Creator<WallPhoto> CREATOR = new Creator<WallPhoto>() {
    @Override
    public WallPhoto createFromParcel(Parcel in) {
        return new WallPhoto(in);
    }

    @Override
    public WallPhoto[] newArray(int size) {
        return new WallPhoto[size];
        


    }
};
private String mUrl;

public WallPhoto(String url) {
    mUrl = url;
}

protected WallPhoto(Parcel in) {
    mUrl = in.readString();
}

public static WallPhoto[] getWallPhotos() {

    return new WallPhoto[]{


            new WallPhoto("https://i.pinimg.com/736x/55/42/b4/5542b4fce27fb35f586db30f22aa7a06.jpg"),
            new WallPhoto("https://i.pinimg.com/736x/dd/46/07/dd4607dfa77d3954ebd3bc5514d3b160.jpg"),
            new WallPhoto("https://i.pinimg.com/736x/b1/a6/d6/b1a6d66f1dc350a6eb07098b031a6a86.jpg"),
            new WallPhoto("https://i.pinimg.com/736x/ea/43/16/ea43160566df2e94804dc8494abad75d.jpg"),
            new WallPhoto("https://i.pinimg.com/736x/2c/9c/e1/2c9ce1ebebcdd9f94bffa7d3a75ba172.jpg"),
            new WallPhoto("https://i.pinimg.com/736x/a7/0a/3d/a70a3d6f310f63df2556233466c0d1a5.jpg"),
            new WallPhoto("https://i.pinimg.com/736x/54/b3/20/54b320780750126d3c2c014af78e2642.jpg"),
            new WallPhoto("https://i.pinimg.com/736x/3f/cc/ec/3fccec232da73ea7efe334cdfa920085.jpg"),
            new WallPhoto("https://i.pinimg.com/736x/3b/c1/9f/3bc19f6a11ce39f1ce534b800001e4e0.jpg"),
            new WallPhoto("https://i.pinimg.com/736x/37/a8/6e/37a86eac7b57ad3f768771870aca68ca.jpg"),
            
    };
}

public String getUrl() {
    return mUrl;
}

public void setUrl(String url) {
    mUrl = url;
}

@Override
public int describeContents() {
    return 0;
}

@Override
public void writeToParcel(Parcel parcel, int i) {
    parcel.writeString(mUrl);
}

}

Answer 1

public void shuffle() {
    int mWallPhotoSize = mWallphoto.length();
    WallPhoto[] shuffleWallphoto = new WallPhoto[mWallPhotoSize];

    boolean[] checkNumber = new boolean[mWallPhotoSize];
    for (int i = 0; i < mWallPhotoSize; i++) {
        int randomNumber = (int)(Math.random()*mWallPhotoSize);
        if (!checkNumber[randomNumber]) {
            checkNumber[randomNumber] = true;
            shuffleWallphoto[i] = mWallphoto[randomNumber];
        } else {
            i--;
        }
        
    }

    mWallphoto = shuffleWallphoto;

}