Android 10.0 系统framework层修改第三方app的dpi的属性功能实现

1.前言

在系统10.0的rom定制化开发中，在对于某些第三方app的适配工作中，由于第三方的app的特定默认的 dpi等configuation等参数设置有点大，导致显得字体有点大，控件有点宽等，导致安装后显示很不协调，所以就需要分析app加载的时候就修改相关的dpi等属性值来实现功能

2.系统framework层修改第三方app的dpi的属性功能实现的核心类




frameworks/base/core/java/android/content/res/Configuration.java



frameworks\base\core\java\android\app\Activity.java

3.系统framework层修改第三方app的dpi的属性功能实现的核心功能分析和实现

Configuration指的是Configuration.java这个类所代表的配置信息它主要就是表示系统的配置信息等，比如屏幕方向, 触摸屏的触摸方式等 Configuration有哪些属性 Manifest指：在Manifest文件中，activity标签的configChanges是否可以使用 Java指：android.content.res.Configuration类中是否存在对应的属性 Configuration和Resouce的关系从Resouce获取资源时，默认使用当前Configuration相匹配的资源。但也可以在运行时，更新Resouce关联的Configuration。 Android 活动(Activity) 活动代表了一个具有用户界面的单一屏幕，如 Java 的窗口或者帧。Android 的活动是 ContextThemeWrapper 类的子类。如果你曾经用 C,C++ 或者 Java 语言编程，你应该知道这些程序从 main() 函数开始。很类似的，Android 系统初始化它的程序是通过活动中的 onCreate() 回调的调用开始的。存在有一序列的回调方法来启动一个活动，同时有一序列的方法来关闭活动

3.1 Configuration.java中相关的信息配置

在实现系统framework层修改第三方app的dpi的属性功能中，通过上述的分析得知，在 Configuration.java中相关的源码配置中得知，在Configuration.java中的相关配置中，看下系统参数的相关配置




 



    public int densityDpi;



 



    /** @hide Hack to get this information from WM to app running in compat mode. */




    public int compatScreenWidthDp;



    /** @hide Hack to get this information from WM to app running in compat mode. */




    public int compatScreenHeightDp;



    /** @hide Hack to get this information from WM to app running in compat mode. */




    public int compatSmallestScreenWidthDp;



 



    public Configuration() {



        unset();



    }



 



    public Configuration(Configuration o) {



        setTo(o);



    }



 



    public void setTo(Configuration o) {



        fontScale = o.fontScale;



        mcc = o.mcc;



        mnc = o.mnc;



        locale = o.locale == null ? null : (Locale) o.locale.clone();



        o.fixUpLocaleList();



        mLocaleList = o.mLocaleList;



        userSetLocale = o.userSetLocale;



        touchscreen = o.touchscreen;



        keyboard = o.keyboard;



        keyboardHidden = o.keyboardHidden;



        hardKeyboardHidden = o.hardKeyboardHidden;



        navigation = o.navigation;



        navigationHidden = o.navigationHidden;



        orientation = o.orientation;



        screenLayout = o.screenLayout;



        colorMode = o.colorMode;



        uiMode = o.uiMode;



        screenWidthDp = o.screenWidthDp;



        screenHeightDp = o.screenHeightDp;



        smallestScreenWidthDp = o.smallestScreenWidthDp;



        densityDpi = o.densityDpi;



        compatScreenWidthDp = o.compatScreenWidthDp;



        compatScreenHeightDp = o.compatScreenHeightDp;



        compatSmallestScreenWidthDp = o.compatSmallestScreenWidthDp;



        assetsSeq = o.assetsSeq;



        seq = o.seq;



        windowConfiguration.setTo(o.windowConfiguration);



    }

在实现系统framework层修改第三方app的dpi的属性功能中，通过上述的分析得知，在 Configuration.java中相关的源码配置中得知，在 setTo(Configuration o)中负责对系统Configuration.java 的相关配置进行重新配置，而 densityDpi = o.densityDpi;就是对dpi进行重新设置，在系统属性 densityDpi代表对dpi的属性设置，在app中可以对这个属性进行设置针对当前app的configuration 的设置功能，接下来看下怎么样配置某个app的相关属性

3.2 Activity.java中相关页面启动功能的设置

在实现系统framework层修改第三方app的dpi的属性功能中，通过上述的分析得知，在Activity中主要负责显示app的每个页面，在这里的每个页面都是从生命周期中生成到销毁的过程，所以说可以在这里根据包名进入到Activity里面的时候，来设置dpi的属性值




 /**




     * Called when the activity is starting.  This is where most initialization



     * should go: calling {@link #setContentView(int)} to inflate the



     * activity's UI, using {@link #findViewById} to programmatically interact



     * with widgets in the UI, calling



     * {@link #managedQuery(android.net.Uri , String[], String, String[], String)} to retrieve



     * cursors for data being displayed, etc.



     *



     * <p>You can call {@link #finish} from within this function, in



     * which case onDestroy() will be immediately called after {@link #onCreate} without any of the



     * rest of the activity lifecycle ({@link #onStart}, {@link #onResume}, {@link #onPause}, etc)



     * executing.



     *



     * <p><em>Derived classes must call through to the super class's



     * implementation of this method.  If they do not, an exception will be



     * thrown.</em></p>



     *



     * @param savedInstanceState If the activity is being re-initialized after



     *     previously being shut down then this Bundle contains the data it most



     *     recently supplied in {@link #onSaveInstanceState}.  <b><i>Note: Otherwise it is null.</i></b>



     *



     * @see #onStart



     * @see #onSaveInstanceState



     * @see #onRestoreInstanceState



     * @see #onPostCreate



     */



    @MainThread



    @CallSuper



    protected void onCreate(@Nullable Bundle savedInstanceState) {



        if (DEBUG_LIFECYCLE) Slog.v(TAG, "onCreate " + this + ": " + savedInstanceState);



 



        if (mLastNonConfigurationInstances != null) {



            mFragments.restoreLoaderNonConfig(mLastNonConfigurationInstances.loaders);



        }



        if (mActivityInfo.parentActivityName != null) {



            if (mActionBar == null) {



                mEnableDefaultActionBarUp = true;



            } else {



                mActionBar.setDefaultDisplayHomeAsUpEnabled(true);



            }



        }



        if (savedInstanceState != null) {



            mAutoFillResetNeeded = savedInstanceState.getBoolean(AUTOFILL_RESET_NEEDED, false);



            mLastAutofillId = savedInstanceState.getInt(LAST_AUTOFILL_ID,



                    View.LAST_APP_AUTOFILL_ID);



 



            if (mAutoFillResetNeeded) {



                getAutofillManager().onCreate(savedInstanceState);



            }



 



            Parcelable p = savedInstanceState.getParcelable(FRAGMENTS_TAG);



            mFragments.restoreAllState(p, mLastNonConfigurationInstances != null




                    ? mLastNonConfigurationInstances.fragments : null);



        }



        mFragments.dispatchCreate();



        dispatchActivityCreated(savedInstanceState);



        if (mVoiceInteractor != null) {



            mVoiceInteractor.attachActivity(this);



        }



        mRestoredFromBundle = savedInstanceState != null;



        mCalled = true;



 



   //add core start




    ActivityManager acitivitymg = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);



    List<ActivityManager.RunningTaskInfo> runningTasks = acitivitymg.getRunningTasks(1);



 



    if (runningTasks != null && !runningTasks.isEmpty()) {



        ComponentName topActivity = runningTasks.get(0).topActivity;



        String packageName = topActivity.getPackageName();



        if ("com.pne.funcation".equals(packageName)) {



            Resources resources = getResources();



            if (resources != null) {



                Configuration configuration = resources.getConfiguration();



 



                if (configuration != null) {



                    DisplayMetrics displayMetrics = new DisplayMetrics();



                    getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);



                    int densityDpi = displayMetrics.densityDpi;



                    // change dpi



                    if (densityDpi != 160) {



                        configuration.densityDpi = 160;



                        resources.updateConfiguration(configuration, 



                                                      resources.getDisplayMetrics());



                    }



                }



            }



        }



    }



    //add core end




    }

在实现系统framework层修改第三方app的dpi的属性功能中，通过上述的分析得知，在Activity的相关源码中，在onCreate(@Nullable Bundle savedInstanceState)中负责构造每一个页面的布局属性开始启动每一个activity页面功能，所以可以在这里通过获取正在运行的app页面，来获取当前的包名根据if ("com.pne.funcation".equals(packageName)) 来设置 Configuration这个app的属性，然后调用resources.updateConfiguration(configuration, resources.getDisplayMetrics()); 来设置configuration.densityDpi = 160;来修改这个app的dpi的功能，就这样实现了相关的功能

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