PreferenceScreen 设置title颜色(andro

系统设置里面自定义Fragment 设置 PreferenceScreen的标题颜色

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:settings="http://schemas.android.com/apk/res-auto"
    android:key="multi_help_menu_main"
    android:title="@string/multi_help_menu_main_title">

    <Preference
        android:key="multi_help_menu_recursos"
        android:title="@string/multi_recursos_title"
        android:icon="@drawable/ic_multi_recursos"
        android:fragment="com.android.settings.multihelpmenu.MultiHelpMenuMultiRecursosFragment" />

    <Preference
        android:key="multi_help_menu_done"
        android:title="@string/multi_help_menu_done_title"
        android:icon="@drawable/ic_multi_help_menu_done"
        android:fragment="com.android.settings.multihelpmenu.MultiHelpMenuDoneFragment" />

    <Preference
        android:key="multi_help_menu_question_mark"
        android:title="@string/multi_help_menu_question_mark_title"
        android:icon="@drawable/ic_multi_help_menu_question_mark"
        android:fragment="com.android.settings.multihelpmenu.MultiHelpMenuQuestionFragment" />

    <Preference
        android:key="multi_help_menu_build"
        android:title="@string/multi_help_menu_build_title"
        android:icon="@drawable/ic_multi_help_menu_build"
        android:fragment="com.android.settings.multihelpmenu.MultiHelpMenuBuildFragment" />

</PreferenceScreen>
---------------------------------自定义Fragment-----------------------------------
package xxx;

import android.app.settings.SettingsEnums;
import android.content.Context;
import android.os.Bundle;
import com.android.settings.R;
import com.android.settings.dashboard.DashboardFragment;
import com.android.settings.SettingsActivity;

import android.graphics.drawable.Drawable;
import com.android.settings.Utils;
import androidx.preference.Preference;
import androidx.preference.PreferenceFragmentCompat;
import androidx.preference.PreferenceScreen;
import android.util.Log;

public class MultiHelpMenuFragment extends DashboardFragment {
    private static final String TAG = "MultiHelpMenuFragment";
    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
    }
    @Override
    public int getMetricsCategory() {
        return SettingsEnums.SETTINGS_MULTI_HELP_MENU_CATEGORY;
    }
    @Override
    protected String getLogTag() {
        return TAG;
    }
    @Override
    protected int getPreferenceScreenResId() {
        return R.xml.multi_help_menu_main;
    }
    @Override
    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
        super.onCreatePreferences(savedInstanceState, rootKey);
        final PreferenceScreen screen = getPreferenceScreen();
        if (screen == null) {
            return;
        }
        // Tint the homepage icons
        final int tintColor = Utils.getHomepageIconColor(getContext());
        final int count = screen.getPreferenceCount();
        for (int i = 0; i < count; i++) {
            final Preference preference = screen.getPreference(i);
            if (preference == null) {
                break;
            }
            final Drawable icon = preference.getIcon();
            if (icon != null) {
                icon.setTint(tintColor);
            }
        }
    }
}

设置title颜色没有，但是没有相关属性；
思路是先看下源码，用的是Androidx,那就继承它重写给view赋值；
androidx.preference_preference.jar

package androidx.preference;

import android.content.Context;
import android.graphics.Color;
import android.util.AttributeSet;
import android.util.Log;
import android.widget.TextView;
import androidx.annotation.RestrictTo;
import androidx.annotation.RestrictTo.Scope;
import androidx.core.content.res.TypedArrayUtils;
import androidx.preference.PreferenceManager.OnNavigateToScreenListener;
import androidx.preference.R.attr;

public class PreferenceScreen extends PreferenceGroup {
    private static final String TAG = "CustomPreferenceScreen";
    private boolean mShouldUseGeneratedIds = true;

    @RestrictTo({Scope.LIBRARY_GROUP_PREFIX})
    public PreferenceScreen(Context context, AttributeSet attrs) {
        super(context, attrs, TypedArrayUtils.getAttr(context, attr.preferenceScreenStyle, 16842891));
    }

    protected void onClick() {
        if (this.getIntent() == null && this.getFragment() == null && this.getPreferenceCount() != 0) {
            OnNavigateToScreenListener listener = this.getPreferenceManager().getOnNavigateToScreenListener();
            if (listener != null) {
                listener.onNavigateToScreen(this);
            }

        }
    }

    protected boolean isOnSameScreenAsChildren() {
        return false;
    }

    public boolean shouldUseGeneratedIds() {
        return this.mShouldUseGeneratedIds;
    }

    public void setShouldUseGeneratedIds(boolean shouldUseGeneratedIds) {
        if (this.isAttached()) {
            throw new IllegalStateException("Cannot change the usage of generated IDs while attached to the androidx.preference hierarchy");
        } else {
            this.mShouldUseGeneratedIds = shouldUseGeneratedIds;
        }
    }


    @Override
    public void onBindViewHolder(PreferenceViewHolder holder) {
        super.onBindViewHolder(holder);
        TextView titleView = (TextView)holder.findViewById(16908310);
        Log.i(TAG, "CustomPreferenceScreen titleView: " +titleView);

        if (titleView != null) {
            titleView.setTextColor(Color.RED);
        }
    }
}

但是它和普通的preference又有区别，没有走onBindViewHolder方法，所以这个titile不是preference所绑定的layout
通过view布局分析title对应view是哪个（layout inspector 13好像获取不了系统view的布局图）
adb shell dumpsys activity top 分析应该是Toolbar

          android.view.ViewStub{db71278 G.E...... ......I. 0,0-0,0 #10201c5 android:id/action_mode_bar_stub}
          android.widget.FrameLayout{f639d51 V.E...... ........ 0,0-600,976 #1020002 android:id/content}
            androidx.coordinatorlayout.widget.CoordinatorLayout{4fed9b6 V.ED..... ........ 0,0-600,976 #7f0a018a app:id/content_parent
}
              com.google.android.material.appbar.AppBarLayout{98e36c2 V.E...... ........ 0,0-600,144 #7f0a0092 app:id/app_bar}
                com.google.android.material.appbar.CollapsingToolbarLayout{f9c56b7 V.ED..... ........ 0,0-600,144 #7f0a0173 app:id/col
lapsing_toolbar}
                  android.widget.Toolbar{86de24 V.E...... ........ 0,24-600,88 #7f0a003f app:id/action_bar}
                    android.widget.TextView{4f3bd8d V.ED..... ........ 80,18-80,46}
                    android.widget.ImageButton{796db42 VFED..C.. ........ 8,0-64,64}
                    android.view.View{915a753 V.ED..... ........ 80,0-584,64}
                    android.widget.ActionMenuView{465b890 V.E...... ........ 592,0-592,64}
              android.widget.FrameLayout{2489cd3 V.E...... ........ 0,144-600,384 #7f0a0189 app:id/content_frame}

最后定位到标题显示在CollapsingToolbarLayout上面， 但是不属于toobar (无法通过setTitleTextColor来改变颜色)，通过TextPaint绘制;

+++ core/SettingsBaseActivity.java  
 import com.google.android.material.resources.TextAppearanceConfig;
 import com.google.android.setupcompat.util.WizardManagerHelper;
 import com.google.android.setupdesign.util.ThemeHelper;
+import android.widget.TextView;
+import android.graphics.Color;
 
 /** Base activity for Settings pages */
 public class SettingsBaseActivity extends FragmentActivity implements CategoryHandler {
             return;
         }
         setActionBar(toolbar);
-
         if (DEBUG_TIMING) {
             Log.d(TAG, "onCreate took " + (System.currentTimeMillis() - startTime) + " ms");
         }
 
     @Override
     public void setTitle(CharSequence title) {
+        Log.d(TAG, "setTitle  "+title);
         super.setTitle(title);
         if (mCollapsingToolbarLayout != null) {
+            Log.d(TAG, "mCollapsingToolbarLayout setTitle  "+title);
             mCollapsingToolbarLayout.setTitle(title);
+            mCollapsingToolbarLayout.setExpandedTitleColor(Color.BLUE);
+            
         }
     }

CollapsingToolbarLayout