1、Android主题切换日夜间模式
1、Google提供了夜间模式方案
首先你需要准备两套资源，一套日见一套夜间，以color为例：在res中新建values-night，然后新建color.xml，日间夜间资源命名要相同，但颜色不同。
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第一步准备好，就可以这样使用，配合SharedPreferences，记录我们是开夜间还是日间，在Application这样写：
SharedPreferences sp = getSharedPreferences("theme_mode",MODE_PRIVATE); boolean nightMode = sp.getBoolean("is_night_mode", false); AppCompatDelegate.setDefaultNightMode(nightMode ? AppCompatDelegate.MODE_NIGHT_YES : AppCompatDelegate.MODE_NIGHT_NO); -
对于上面的，介绍下 AppCompatDelegate.setDefaultNightMode几种模式：
MODE_NIGHT_NO： 亮色(light)主题，不使用夜间模式 MODE_NIGHT_YES：暗色(dark)主题，使用夜间模式 MODE_NIGHT_AUTO：根据当前时间自动切换 亮色( light )/暗色( dark )主题（22：00-07：00时间段内自动切换为夜间模式） MODE_NIGHT_FOLLOW_SYSTEM(默认选项)：设置为跟随系统，通常为MODE_NIGHT_NO -
在Activity中切换：
// 获取当前模式 int currentNightMode = getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK; // 将为夜间模式保存到SharedPreferences SharedPreferences sp = getSharedPreferences("theme_mode",MODE_PRIVATE); sp.edit().putBoolean("is_night_mode",currentNightMode == Configuration.UI_MODE_NIGHT_NO).commit(); // 切换模式 getDelegate().setDefaultNightMode(currentNightMode == Configuration.UI_MODE_NIGHT_NO ? AppCompatDelegate.MODE_NIGHT_YES : AppCompatDelegate.MODE_NIGHT_NO); // 重启Activity //recreate(); recreate存在一些问题 startActivity(new Intent(this,MainActivity.class)); finish();
2、Android-skin-support
1、使用：
github写的很详细
https://github.com/ximsfei/Android-skin-support#%E5%AF%BC%E5%85%A5
2、原理分析：
LayoutInflater有一个内部接口Factory，系统会使用它去做XML到View的转换，而系统也提供了setFactory的方法，用户设置了，则用我们设置的，这样系统就会走我们Factory的onCreateView,他会返回一个我们定制化的View。
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首先，Activity会在onCreate中初始化Factory，我们没有设置就返回系统默认的：
@Override public void installViewFactory() { LayoutInflater layoutInflater = LayoutInflater.from(mContext); if (layoutInflater.getFactory() == null) { LayoutInflaterCompat.setFactory(layoutInflater, this); //系统默认的 } else { if (!(LayoutInflaterCompat.getFactory(layoutInflater) instanceof AppCompatDelegateImplV9)) { Log.i(TAG, "The Activity's LayoutInflater already has a Factory installed" + " so we can not install AppCompat's"); } } } -
Factory会在layoutInflater.inflate，最终会走Factory.createView，看看系统的：
@Override public View createView(View parent, final String name, @NonNull Context context, @NonNull AttributeSet attrs) { if (mAppCompatViewInflater == null) { mAppCompatViewInflater = new AppCompatViewInflater(); } boolean inheritContext = false; if (IS_PRE_LOLLIPOP) { inheritContext = (attrs instanceof XmlPullParser) // If we have a XmlPullParser, we can detect where we are in the layout ? ((XmlPullParser) attrs).getDepth() > 1 // Otherwise we have to use the old heuristic : shouldInheritContext((ViewParent) parent); } return mAppCompatViewInflater.createView(parent, name, context, attrs, inheritContext, IS_PRE_LOLLIPOP, /* Only read android:theme pre-L (L+ handles this anyway) */ true, /* Read read app:theme as a fallback at all times for legacy reasons */ VectorEnabledTintResources.shouldBeUsed() /* Only tint wrap the context if enabled */ ); } -
再看下去：
public final View createView(View parent, final String name, @NonNull Context context, @NonNull AttributeSet attrs, boolean inheritContext, boolean readAndroidTheme, boolean readAppTheme, boolean wrapContext) { final Context originalContext = context; // We can emulate Lollipop's android:theme attribute propagating down the view hierarchy // by using the parent's context if (inheritContext && parent != null) { context = parent.getContext(); } if (readAndroidTheme || readAppTheme) { // We then apply the theme on the context, if specified context = themifyContext(context, attrs, readAndroidTheme, readAppTheme); } if (wrapContext) { context = TintContextWrapper.wrap(context); } View view = null; // We need to 'inject' our tint aware Views in place of the standard framework versions switch (name) { case "TextView": view = new AppCompatTextView(context, attrs); break; case "ImageView": view = new AppCompatImageView(context, attrs); break; case "Button": view = new AppCompatButton(context, attrs); break; case "EditText": view = new AppCompatEditText(context, attrs); break; case "Spinner": view = new AppCompatSpinner(context, attrs); break; case "ImageButton": view = new AppCompatImageButton(context, attrs); break; case "CheckBox": view = new AppCompatCheckBox(context, attrs); break; case "RadioButton": view = new AppCompatRadioButton(context, attrs); break; case "CheckedTextView": view = new AppCompatCheckedTextView(context, attrs); break; case "AutoCompleteTextView": view = new AppCompatAutoCompleteTextView(context, attrs); break; case "MultiAutoCompleteTextView": view = new AppCompatMultiAutoCompleteTextView(context, attrs); break; case "RatingBar": view = new AppCompatRatingBar(context, attrs); break; case "SeekBar": view = new AppCompatSeekBar(context, attrs); break; } if (view == null && originalContext != context) { // If the original context does not equal our themed context, then we need to manually // inflate it using the name so that android:theme takes effect. view = createViewFromTag(context, name, attrs); } if (view != null) { // If we have created a view, check it's android:onClick checkOnClickListener(view, attrs); } return view; } -
可以看到系统也是根据XML解析的名字new出控件，但上面都是AppCompat类型，其他类型其实的通过类加载器创建出来的，那么XML使用TextView其实是AppCompatTextView，利用这一个原理，看看Android-skin-support：
private View createViewFromFV(Context context, String name, AttributeSet attrs) { View view = null; if (name.contains(".")) { return null; } switch (name) { case "View": view = new SkinCompatView(context, attrs); break; case "LinearLayout": view = new SkinCompatLinearLayout(context, attrs); break; case "RelativeLayout": view = new SkinCompatRelativeLayout(context, attrs); break; case "FrameLayout": view = new SkinCompatFrameLayout(context, attrs); break; case "TextView": view = new SkinCompatTextView(context, attrs); break; case "ImageView": view = new SkinCompatImageView(context, attrs); break; case "Button": view = new SkinCompatButton(context, attrs); break; case "EditText": view = new SkinCompatEditText(context, attrs); break; case "Spinner": view = new SkinCompatSpinner(context, attrs); break; case "ImageButton": view = new SkinCompatImageButton(context, attrs); break; case "CheckBox": view = new SkinCompatCheckBox(context, attrs); break; case "RadioButton": view = new SkinCompatRadioButton(context, attrs); break; case "RadioGroup": view = new SkinCompatRadioGroup(context, attrs); break; case "CheckedTextView": view = new SkinCompatCheckedTextView(context, attrs); break; case "AutoCompleteTextView": view = new SkinCompatAutoCompleteTextView(context, attrs); break; case "MultiAutoCompleteTextView": view = new SkinCompatMultiAutoCompleteTextView(context, attrs); break; case "RatingBar": view = new SkinCompatRatingBar(context, attrs); break; case "SeekBar": view = new SkinCompatSeekBar(context, attrs); break; case "ProgressBar": view = new SkinCompatProgressBar(context, attrs); break; case "ScrollView": view = new SkinCompatScrollView(context, attrs); break; } return view; } -
这就返回了自己定制好的View了，那么回到前面，我们需要在super.onCreate前设置自己的Factory，不可能每个Activity都设置一遍，那么利用Application.ActivityLifecycleCallbacks统一设置：
@Override public void onActivityCreated(Activity activity, Bundle savedInstanceState) { if (activity instanceof AppCompatActivity) { LayoutInflater layoutInflater = activity.getLayoutInflater(); try { Field field = LayoutInflater.class.getDeclaredField("mFactorySet"); field.setAccessible(true); field.setBoolean(layoutInflater, false); LayoutInflaterCompat.setFactory(activity.getLayoutInflater(), getSkinDelegate((AppCompatActivity) activity)); } catch (NoSuchFieldException | IllegalArgumentException | IllegalAccessException e) { e.printStackTrace(); } updateStatusBarColor(activity); updateWindowBackground(activity); } }