Question

我已经制作了Android应用程序，其中onLaunch我想显示SplashScreen 3秒钟＆amp;然后AppInro（如果第一次在幻灯片中发布）＆amp;然后MainActivity启动。实际上我在最后做了闪屏活动，但我把它设置得很好但是现在在splashScreen MainActivity直接启动之后。 AppIntro没有显示（即使在第一次启动时）在添加SplashScreen活动之前AppIntro工作正常。

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="info.androidhive.introslider">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.CAMERA" />

    <uses-feature android:name="android.hardware.camera" />

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".SpashScreen">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".MainActivity"
            android:label="Order Medicines"
            android:theme="@style/AppTheme.NoActionBar" />
        <activity
            android:name="info.androidhive.welcomeslider.MainActivity"
            //In above line code it shows Can not resolve symbol MainActivity
            android:label="@string/title_activity_splash"
            android:theme="@style/AppTheme"></activity>
    </application>

</manifest>

SplashScreen

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;

public class SpashScreen extends Activity {
    private PrefManager prefManager;

    // Splash screen timer
    private static int SPLASH_TIME_OUT = 3000;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splash);

        new Handler().postDelayed(new Runnable() {

        /*
         * Showing splash screen with a timer. This will be useful when you
         * want to show case your app logo / company
         */

            @Override
            public void run() {

                // This method will be executed once the timer is over
                // Start your app main activity
                Intent i;

                if (prefManager.isFirstTimeLaunch()) {
                    i = new Intent(SpashScreen.this, WelcomeActivity.class);
                    prefManager.setFirstTimeLaunch(false);
                } else {
                    i = new Intent(SpashScreen.this, MainActivity.class);
                }

                startActivity(i);
                finish();
            }
        }, SPLASH_TIME_OUT);
    }

}

AppIntro（WelcomeActivity）

import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.text.Html;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

public class WelcomeActivity extends AppCompatActivity {

    private ViewPager viewPager;
    private MyViewPagerAdapter myViewPagerAdapter;
    private LinearLayout dotsLayout;
    private TextView[] dots;
    private int[] layouts;
    private Button btnSkip, btnNext;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Making notification bar transparent
        if (Build.VERSION.SDK_INT >= 21) {
            getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
        }

        setContentView(R.layout.activity_welcome);

        viewPager = (ViewPager) findViewById(R.id.view_pager);
        dotsLayout = (LinearLayout) findViewById(R.id.layoutDots);
        btnSkip = (Button) findViewById(R.id.btn_skip);
        btnNext = (Button) findViewById(R.id.btn_next);


        // layouts of all welcome sliders
        // add few more layouts if you want
        layouts = new int[]{
                R.layout.welcome_slide1,
                R.layout.welcome_slide2,
                R.layout.welcome_slide3,
                R.layout.welcome_slide4};

        // adding bottom dots
        addBottomDots(0);

        // making notification bar transparent
        changeStatusBarColor();

        myViewPagerAdapter = new MyViewPagerAdapter();
        viewPager.setAdapter(myViewPagerAdapter);
        viewPager.addOnPageChangeListener(viewPagerPageChangeListener);

        btnSkip.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                launchHomeScreen();
            }
        });

        btnNext.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // checking for last page
                // if last page home screen will be launched
                int current = getItem(+1);
                if (current < layouts.length) {
                    // move to next screen
                    viewPager.setCurrentItem(current);
                } else {
                    launchHomeScreen();
                }
            }
        });
    }

    private void addBottomDots(int currentPage) {
        dots = new TextView[layouts.length];

        int[] colorsActive = getResources().getIntArray(R.array.array_dot_active);
        int[] colorsInactive = getResources().getIntArray(R.array.array_dot_inactive);

        dotsLayout.removeAllViews();
        for (int i = 0; i < dots.length; i++) {
            dots[i] = new TextView(this);
            dots[i].setText(Html.fromHtml("&#8226;"));
            dots[i].setTextSize(35);
            dots[i].setTextColor(colorsInactive[currentPage]);
            dotsLayout.addView(dots[i]);
        }

        if (dots.length > 0)
            dots[currentPage].setTextColor(colorsActive[currentPage]);
    }

    private int getItem(int i) {
        return viewPager.getCurrentItem() + i;
    }

    private void launchHomeScreen() {
        startActivity(new Intent(WelcomeActivity.this, MainActivity.class));
        finish();
    }

    //  viewpager change listener
    ViewPager.OnPageChangeListener viewPagerPageChangeListener = new ViewPager.OnPageChangeListener() {

        @Override
        public void onPageSelected(int position) {
            addBottomDots(position);

            // changing the next button text 'NEXT' / 'GOT IT'
            if (position == layouts.length - 1) {
                // last page. make button text to GOT IT
                btnNext.setText(getString(R.string.start));
                btnSkip.setVisibility(View.GONE);
            } else {
                // still pages are left
                btnNext.setText(getString(R.string.next));
                btnSkip.setVisibility(View.VISIBLE);
            }
        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {

        }

        @Override
        public void onPageScrollStateChanged(int arg0) {

        }
    };

    /**
     * Making notification bar transparent
     */
    private void changeStatusBarColor() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            Window window = getWindow();
            window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            window.setStatusBarColor(Color.TRANSPARENT);
        }
    }

    /**
     * View pager adapter
     */
    public class MyViewPagerAdapter extends PagerAdapter {
        private LayoutInflater layoutInflater;

        public MyViewPagerAdapter() {
        }

        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);

            View view = layoutInflater.inflate(layouts[position], container, false);
            container.addView(view);

            return view;
        }

        @Override
        public int getCount() {
            return layouts.length;
        }

        @Override
        public boolean isViewFromObject(View view, Object obj) {
            return view == obj;
        }


        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            View view = (View) object;
            container.removeView(view);
        }
    }
}

Answer 1

您永远不会打开WelcomeActivity - 您直接从MainActivity打开SplashActivity，因此永远不会查询PrefManager。

SplashActivity应该做的是：

new Handler().postDelayed(new Runnable() {

        /*
         * Showing splash screen with a timer. This will be useful when you
         * want to show case your app logo / company
         */

        @Override
        public void run() {

            // This method will be executed once the timer is over
            // Start your app main activity
            Intent i;

            if (prefManager.isFirstTimeLaunch()) {
               i = new Intent(SpashScreen.this, WelcomeActivity.class);
               prefManager.setFirstTimeLaunch(false);
            } else {
               i = new Intent(SplashScreen.this, MainActivity.class)
            }

            startActivity(i);
            finish();
        }
    }, SPLASH_TIME_OUT);

并从WelcomeActivity删除所有首次启动检查代码。

Answer 2

您没有初始化prefManager，请先尝试初始化。

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;

public class SpashScreen extends Activity {
    private PrefManager prefManager;

    // Splash screen timer
    private static int SPLASH_TIME_OUT = 3000;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splash);

        // HERE prefManager INITIALIZED
        prefManager = getPreferences(Context.MODE_PRIVATE);

        new Handler().postDelayed(new Runnable() {

        /*
         * Showing splash screen with a timer. This will be useful when you
         * want to show case your app logo / company
         */

            @Override
            public void run() {

                // This method will be executed once the timer is over
                // Start your app main activity
                Intent i;

                if (prefManager.isFirstTimeLaunch()) {
                    i = new Intent(SpashScreen.this, WelcomeActivity.class);
                    prefManager.setFirstTimeLaunch(false);
                } else {
                    i = new Intent(SpashScreen.this, MainActivity.class);
                }

                startActivity(i);
                finish();
            }
        }, SPLASH_TIME_OUT);
    }

}

Answer 3

你没有初始化prefManager，这是正确的方法这对我有用。

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_splash_screen);

    try {
        int netStatus = NetworkUtil.getConnectivityStatus(getBaseContext());
        if (netStatus == 0) {
            Intent intent = new Intent(SplashScreen.this,NoInternetActivity.class);
            startActivity(intent);
            finish();

        } else {
            new Handler().postDelayed(new Runnable() {
                @Override
                public void run() {
                    PrefManager prefManager = new PrefManager(getApplicationContext());
                    // This method will be executed once the timer is over
                    // Start your app main activity
                    if(prefManager.isFirstTimeLaunch()){
                        intent = new Intent(SplashScreen.this, WelcomeActivity.class);
                        prefManager.setFirstTimeLaunch(true);
                    }else {
                        intent = new Intent(SplashScreen.this,MainActivity.class);
                    }
                    startActivity(intent);
                    // close this activity
                    finish();
                }
            }, SPLASH_TIME_OUT);
        }
    }catch (RuntimeException e){
        e.printStackTrace();
    }
    }

@Override
protected void attachBaseContext(Context base) {
    super.attachBaseContext(base);
    MultiDex.install(this);
}

}

显示闪屏＆amp;然后AppIntro（第一次启动）比mainactivity不工作

3 个答案: