Question

我正在开发一款壁纸应用，我正在使用启动画面。

我的应用程序始终显示与启动画面相同的图像，但我想显示随机启动画面。

因此，每当我的应用启动时，它都会显示不同的图像作为启动画面。

我该如何做到这一点？

启动画面XML：

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ImageView android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:src="@drawable/splash_screen"
        android:scaleType="centerCrop"/>


</LinearLayout>

启动屏幕活动：

import java.util.ArrayList;
import java.util.List;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.Window;
import android.widget.Toast;

import com.android.volley.Request.Method;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.usd.amazingwallpapershd.R;
import com.usd.amazingwallpapershd.app.AppConst;
import com.usd.amazingwallpapershd.app.AppController;
import com.usd.amazingwallpapershd.picasa.model.Category;

@SuppressLint("NewApi")
public class SplashActivity extends Activity {
    private static final String TAG = SplashActivity.class.getSimpleName();
    private static final String TAG_FEED = "feed", TAG_ENTRY = "entry",
            TAG_GPHOTO_ID = "gphoto$id", TAG_T = "$t",
            TAG_ALBUM_TITLE = "title";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().requestFeature(Window.FEATURE_ACTION_BAR);
        getActionBar().hide();
        setContentView(R.layout.activity_splash);

        // Picasa request to get list of albums
        String url = AppConst.URL_PICASA_ALBUMS
                .replace("_PICASA_USER_", AppController.getInstance()
                        .getPrefManger().getGoogleUserName());

        Log.d(TAG, "Albums request url: " + url);

        // Preparing volley's json object request
        JsonObjectRequest jsonObjReq = new JsonObjectRequest(Method.GET, url,
                null, new Response.Listener<JSONObject>() {

                    @Override
                    public void onResponse(JSONObject response) {
                        Log.d(TAG, "Albums Response: " + response.toString());
                        List<Category> albums = new ArrayList<Category>();
                        try {
                            // Parsing the json response
                            JSONArray entry = response.getJSONObject(TAG_FEED)
                                    .getJSONArray(TAG_ENTRY);

                            // loop through albums nodes and add them to album
                            // list
                            for (int i = 0; i < entry.length(); i++) {
                                JSONObject albumObj = (JSONObject) entry.get(i);
                                // album id
                                String albumId = albumObj.getJSONObject(
                                        TAG_GPHOTO_ID).getString(TAG_T);

                                // album title
                                String albumTitle = albumObj.getJSONObject(
                                        TAG_ALBUM_TITLE).getString(TAG_T);

                                Category album = new Category();
                                album.setId(albumId);
                                album.setTitle(albumTitle);

                                // add album to list
                                albums.add(album);

                                Log.d(TAG, "Album Id: " + albumId
                                        + ", Album Title: " + albumTitle);
                            }

                            // Store albums in shared pref
                            AppController.getInstance().getPrefManger()
                                    .storeCategories(albums);

                            // String the main activity
                            Intent intent = new Intent(getApplicationContext(),
                                    MainActivity.class);
                            startActivity(intent);
                            // closing spalsh activity
                            finish();

                        } catch (JSONException e) {
                            e.printStackTrace();
                            Toast.makeText(getApplicationContext(),
                                    getString(R.string.msg_unknown_error),
                                    Toast.LENGTH_LONG).show();
                        }

                    }
                }, new Response.ErrorListener() {

                    @SuppressWarnings("deprecation")
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        Log.e(TAG, "Volley Error: " + error.getMessage());

                        // show error toast
                        Toast.makeText(getApplicationContext(),
                                getString(R.string.splash_error),
                                Toast.LENGTH_LONG).show();

                        // Unable to fetch albums
                        // check for existing Albums data in Shared Preferences
                        if (AppController.getInstance().getPrefManger()
                                .getCategories() != null
                                && AppController.getInstance().getPrefManger()
                                        .getCategories().size() > 0) {
                            // String the main activity
                            Intent intent = new Intent(getApplicationContext(),
                                    MainActivity.class);
                            startActivity(intent);
                            // closing spalsh activity
                            finish();
                        } else {
                            // Albums data not present in the shared preferences
                            // Launch settings activity, so that user can modify
                            // the settings

                            // Intent i = new Intent(SplashActivity.this,
                            // SettingsActivity.class);
                            // // clear all the activities
                            // i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK
                            // | Intent.FLAG_ACTIVITY_CLEAR_TASK);
                            // startActivity(i);

                            AlertDialog alertDialog = new AlertDialog.Builder(
                                    SplashActivity.this).create();
                            alertDialog
                                    .setMessage("Please connect to the internet and try again");
                            alertDialog.setButton("OK",
                                    new DialogInterface.OnClickListener() {
                                        public void onClick(
                                                DialogInterface dialog,
                                                int which) {
                                            finish();
                                        }
                                    });
                            alertDialog.show();

                        }

                    }
                });

        // disable the cache for this request, so that it always fetches updated
        // json
        jsonObjReq.setShouldCache(false);

        // Making the request
        AppController.getInstance().addToRequestQueue(jsonObjReq);

    }

}

Answer 1

创建一个包含所有可绘制id的数组，使用nextInt生成介于0和数组长度之间的值。然后将其设置为背景。

我没有测试过，但它应该可以正常工作。

int[] ids = new int[]{R.drawable.yourimage,R.drawable.yourimage2};
Random randomGenerator = new Random();
int r= randomGenerator.nextInt(ids.length);
this.yourImageView.setImageDrawable(getResources().getDrawable(ids[r]));

Answer 2

// Randomise a background
        int[] yourListOfImages= {R.drawable.splash_1, R.drawable.splash_2, R.drawable.splash_3, R.drawable.splash_4, R.drawable.splash_5, R.drawable.splash_6};

        Random random = new Random(System.currentTimeMillis());
        int posOfImage = random.nextInt(yourListOfImages.length - 1);

        ImageView imageView= (ImageView) findViewById(R.id.splash_imageview);
        imageView.setBackgroundResource(yourListOfImages[posOfImage]);

如何显示随机启动画面（android）

2 个答案: