如何从启动页面过渡到主要活动？

Question

Currently, my app loads the splash screen and stays that way. I think my main problem is with the Android life cycle. I have the splash page as the onCreate, and the main activity (which starts with private final, below) is also onCreate, but I don't think this is correct. Also, each activity is in one java file. Is this correct? How do I get my splash page to load, kill itself, then load my main activity?

Here's my MainActivity.java:

package com.deliveryfor;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.LatLng;

public class MainActivity extends Activity {

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.splash); 

        Thread Timer = new Thread() { 
            public void run() { 
                try { sleep(3000); 

                startActivity (new Intent ("android.intent.action.SPLASH")); 


                } catch (InterruptedException e) { 
                    e.printStackTrace(); 

                } 

                finally { 

                    finish(); 

                } 

            } 

        }; 

        Timer.start(); 

    }

    private final LatLng LOCATION_STATE = new LatLng(49.27645, -122.917587);
    private final LatLng LOCATION_CITY = new LatLng(49.187500, -122.849000);
    private final LatLng LOCATION_YOU = new LatLng(49.187500, -122.849000);

    private GoogleMap map;



    protected void onCreate() {
        super.onCreate(null);
        setContentView(R.layout.activity_main);

        map  = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();

        map.setMyLocationEnabled(true);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    public void onClick_State(View v) {
        map.setMapType(GoogleMap.MAP_TYPE_HYBRID);
        CameraUpdate update = CameraUpdateFactory.newLatLngZoom(LOCATION_YOU, 9);
        map.animateCamera(update);
    }
    public void onClick_City(View v) {
        map.setMapType(GoogleMap.MAP_TYPE_TERRAIN);
        CameraUpdate update = CameraUpdateFactory.newLatLngZoom(LOCATION_CITY, 16);
        map.animateCamera(update);

    }
    public void onClick_You(View v) {
        map.setMapType(GoogleMap.MAP_TYPE_NORMAL);
        CameraUpdate update = CameraUpdateFactory.newLatLngZoom(LOCATION_STATE, 18);
        map.animateCamera(update);

    }

}

And here's the Menu.java (splash page):

package com.deliveryfor;

import android.app.Activity;
import android.os.Bundle;

public class Menu extends Activity { 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView (R.layout.splash); }




    }

Answer 1

You have to create the Splash Activity as a classical activity, and you have to declare in the Manifest that it will be the first launched activity. Add this line into the activity splash tag:

<intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>

Then, in your SplashActivity.java , in the onCreate(), you add the code that automatically launch your MainActivity . I use a TimerTask like so:

Timer timer = new Timer();
        timer.schedule(new TimerTask(){

            @Override
            public void run() {
                // TODO Auto-generated method stub

                Intent toHomePage = new Intent(context,MainActivity.class);
                startActivity(toHomePage);
                finish();
            }}, 5000);

5000 means that the Intent toHomePage is gonna be launched after 5 seconds. Hope it helps ya!

Answer 2

You need to create an Intent to launch your MainActivity. Right now the code for Menu does nothing apart from creating its UI. The official documentation describes how to do this.

You will need something like this :

Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);

You may also want to reconsider using a splash screen altogether, unless you have a compelling reason for it (which does not seem to be the case). Read this blog post for details. Here's an extract I find quite interesting :

A splash screen can be used to make resources available before an application starts. Personally I think it is not necessary in 98% of the cases. It may be useful for applications actively relying on heavy resources such as Google Earth, Sky Map, or games but this is not applicable to simple utility applications such as feed readers, social network apps, news readers, etc. You should not require a network connection at startup nor do heavy computations.

Answer 3

i use it like this:

public class SplashActivity extends Activity{
    private final static long SPLASH_TIME_OUT = 2000;

    // SplashActivity --> serves as entry-point for the app at several situations
    @Override
    protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_splash);                      
         new Handler().postDelayed(new Runnable() {

              @Override
              public void run() {

                Intent i = new Intent(SplashActivity.this, RegisterActivity.class);
                startActivity(i);
                // close this activity
                finish();
              }
        }, SPLASH_TIME_OUT);
    }   
}

Answer 4

I added this Activity to first page as MainActivity.java:

public class MainActivity extends AppCompatActivity {
    oAuth_Model oAuth_model;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);

        showBasicSplash();
    }
    private void showBasicSplash() {
        new Thread(){
            @Override
            public void run() {
                super.run();

                try {
                    Thread.sleep(1500);
                    handler.sendEmptyMessage(0);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }.start();
    }

    @SuppressLint("HandlerLeak")
    Handler handler = new Handler(){
        public void handleMessage(Message m){
            if (getBoolean(Constant.AFTERLANG)){
                Intent intent = new Intent(MainActivity.this, Landing_three.class);
                startActivity(intent);
                finish();
            }else {
                Intent intent = new Intent(MainActivity.this, Activity_Sec.class);
                startActivity(intent);
                finish();
            }
        }
    };
}

And added this Activity to Manifests.xml :

<activity android:name=".MainActivity"
        android:configChanges="orientation"
        android:screenOrientation="portrait">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

And kill Mainactivity after intent to other activities.

finish();