这篇文章是基于OSCHINA Android客户端4.1.7版本的分析，之前很多人都分析过源码，但是都是几年前的代码分析，随着时间的推移，开源中国的源码也在变化，接下来的一段时间我将分享我通过学习开源中国的代码所获得东西。
研究一个APP或者一个网站的源码，最开始的时候一定会从APP或者网站的入口学习。OSCHINA的入口从下的配置文件可以找到AndroidManifest.xml
<application android:name=".OSCApplication" android:allowBackup="false" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:theme="@style/App.Theme.Light" tools:replace="android:allowBackup"> <meta-data android:name="android.max_aspect" android:value="2.1" /> <activity android:name=".improve.main.splash.SplashActivity" android:label="@string/app_name" android:screenOrientation="portrait" android:theme="@style/App.Theme.Launch"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> ...... ...... </application>通过可以判断开源中国的入口文件就是SplashActivity
SplashActivity源码
package net.oschina.app.improve.main.splash; import android.content.Context; import android.content.Intent; import android.text.TextUtils; import android.view.View; import android.widget.FrameLayout; import com.baidu.mobstat.SendStrategyEnum; import com.baidu.mobstat.StatService; import net.oschina.app.OSCApplication; import net.oschina.app.R; import net.oschina.app.Setting; import net.oschina.app.improve.account.AccountHelper; import net.oschina.app.improve.app.AppOperator; import net.oschina.app.improve.base.activities.BaseActivity; import net.oschina.app.improve.bean.Launcher; import net.oschina.app.improve.bean.User; import net.oschina.app.improve.main.MainActivity; import net.oschina.app.improve.main.introduce.IntroduceActivity; import net.oschina.app.improve.main.tabs.DynamicTabFragment; import net.oschina.app.improve.main.update.OSCSharedPreference; import net.oschina.app.improve.utils.CacheManager; import java.io.File; import butterknife.Bind; /** * 启动页设计 * Created by huanghaibin on 2017/11/25. */ public class SplashActivity extends BaseActivity { @Bind(R.id.frameSplash) FrameLayout mFlameSplash; @Bind(R.id.fl_content) FrameLayout mFlameContent; private boolean isShowAd; public static void show(Context context) { System.out.println("SplashActivity:"+"show()方法"); context.startActivity(new Intent(context, SplashActivity.class)); } @Override protected int getContentView() { System.out.println("SplashActivity:"+"getContentView()方法"); return R.layout.activity_splash; } @Override protected void initWidget() { super.initWidget(); } @Override protected void initData() { super.initData(); System.out.println("SplashActivity:"+"initData()方法"); StatService.setSendLogStrategy(this, SendStrategyEnum.APP_START, 1, false); StatService.start(this); Launcher launcher = CacheManager.readJson(OSCApplication.getInstance(), "Launcher", Launcher.class); String savePath = OSCApplication.getInstance().getCacheDir() + "/launcher"; System.out.println("SplashActivity:"+"launcher方法"); File file = new File(savePath); if (launcher != null && !launcher.isExpired() && file.exists()) { System.out.println("SplashActivity:"+"initData()方法"); isShowAd = true; mFlameSplash.setVisibility(View.GONE); mFlameContent.setVisibility(View.VISIBLE); addFragment(R.id.fl_content, AdFragment.newInstance(launcher)); } AppOperator.runOnThread(new Runnable() { @Override public void run() { doMerge(); } }); } private void doMerge() { // 判断是否是新版本 if (Setting.checkIsNewVersion(this)) { // Cookie迁移 System.out.println("SplashActivity:"+"doMerge()方法"); String cookie = OSCApplication.getInstance().getProperty("cookie"); if (!TextUtils.isEmpty(cookie)) { OSCApplication.getInstance().removeProperty("cookie"); User user = AccountHelper.getUser(); user.setCookie(cookie); AccountHelper.updateUserCache(user); OSCApplication.reInit(); } } // 栏目相关数据合并操作 DynamicTabFragment.initTabPickerManager(); if (isShowAd) return; // Delay... try { Thread.sleep(800); } catch (InterruptedException e) { e.printStackTrace(); } // 完成后进行跳转操作 redirectTo(); } private void redirectTo() { System.out.println("SplashActivity:"+"redirectTo() 方法"); if (OSCSharedPreference.getInstance().isFirstInstall()) { IntroduceActivity.show(this); } else { MainActivity.show(this); } finish(); } @Override public void onBackPressed() { //super.onBackPressed(); } }一个activity启动最开始应该是onCreate()方法，这个类中没有onCreate方法。是因为onCreate方法在抽象类BaseActivity中，基类中写了onCreate方法，以后的无论什么类继承基类就都可以，免去了重复代码。
