Android8.1 Launcher3修改app图标

首先将chrome加入进来：
vendor/mediatek/proprietary/packages/3rd-party/chrome/
这个目录下创建一个chrome模块，
将apk放到这里，并添加mk文件：

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)

LOCAL_MODULE := chrome
LOCAL_MODULE_TAGS := optional
LOCAL_SRC_FILES := $(LOCAL_MODULE).apk
LOCAL_MODULE_CLASS := APPS
LOCAL_MODULE_SUFFIX := $(COMMON_ANDROID_PACKAGE_SUFFIX)
LOCAL_CERTIFICATE := PRESIGNED
LOCAL_MULTILIB := 32
LOCAL_DEX_PREOPT := ture
include $(BUILD_PREBUILT)

然后在device/mediatek/common/device.mk中添加一句：

PRODUCT_PACKAGES += chrome

这样就能顺利的将chrome编译到我们的项目中来了；然后在mk中找到原生的浏览器的定义地方，将他注释就ok。
下面就是替换chrome的图标
Launcher中基本关于图片的处理都在这个类中：
src/com/android/launcher3/IconCache.java
当然图标的生成和我们要做的替换也是不例外的,共有3个地方：
a.

@Thunk synchronized void addIconToDBAndMemCache(LauncherActivityInfo app,
            PackageInfo info, long userSerial, boolean replaceExisting) {
        final ComponentKey key = new ComponentKey(app.getComponentName(), app.getUser());
        CacheEntry entry = null;
        if (!replaceExisting) {
            entry = mCache.get(key);
            // We can't reuse the entry if the high-res icon is not present.
            if (entry == null || entry.isLowResIcon || entry.icon == null) {
                entry = null;
            }
        }
        if (entry == null) {
            entry = new CacheEntry();
            entry.icon = LauncherIcons.createIconBitmap(getFullResIcon(app), mContext);
            /*  begin */
            if (app.getComponentName() != null && app.getComponentName().getPackageName() != null
                    && app.getComponentName().getPackageName().equals("com.android.chrome")) {
                entry.icon = IconUtil.getBitmap(mContext, R.drawable.icon_chrome);
            }
            /*  end */
        }
        entry.title = app.getLabel();
        entry.contentDescription = mUserManager.getBadgedLabelForUser(entry.title, app.getUser());
        mCache.put(key, entry);

        Bitmap lowResIcon = generateLowResIcon(entry.icon);
        ContentValues values = newContentValues(entry.icon, lowResIcon, entry.title.toString(),
                app.getApplicationInfo().packageName);
        addIconToDB(values, app.getComponentName(), info, userSerial);
    }

b.

protected CacheEntry cacheLocked(
            @NonNull ComponentName componentName,
            @NonNull Provider infoProvider,
            UserHandle user, boolean usePackageIcon, boolean useLowResIcon) {
     .....
     
     /*  begin */
        if (componentName != null && componentName.getPackageName() != null && componentName.getPackageName().equals("com.android.chrome")) {
            entry.icon = IconUtil.getBitmap(mContext, R.drawable.icon_chrome);
        }
    /*  end */
        return entry;
    }

c.

private CacheEntry getEntryForPackageLocked(String packageName, UserHandle user,
            boolean useLowResIcon) {
       ......
        /* begin */
                    if("com.android.chrome".equals(packageName)){
                        icon = IconUtil.getBitmap(mContext,R.drawable.icon_chrome);
                    }
         /* end */
                    Bitmap lowResIcon =  generateLowResIcon(icon);
                    entry.title = appInfo.loadLabel(mPackageManager);
                    entry.contentDescription = mUserManager.getBadgedLabelForUser(entry.title, user);
                    entry.icon = useLowResIcon ? lowResIcon : icon;
                    entry.isLowResIcon = useLowResIcon;
......

还有一个getBitmap()方法：

public static Bitmap getBitmap(Context context, int res) {
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inPreferredConfig = Bitmap.Config.ARGB_4444;
        return BitmapFactory.decodeResource(context.getResources(), res, options);
    }

这样就大功告成啦!