要在你的工具栏中使用自定义标题，你需要做的是记住，工具栏只是一个花哨的ViewGroup，所以你可以添加一个自定义标题，如下所示:

<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar_top"
    android:layout_height="wrap_content"
    android:layout_width="match_parent"
    android:minHeight="?android:attr/actionBarSize"
    android:background="@color/action_bar_bkgnd"
    app:theme="@style/ToolBarTheme" >


     <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Toolbar Title"
        android:layout_gravity="center"
        android:id="@+id/toolbar_title" />


    </android.support.v7.widget.Toolbar>

这意味着你可以样式的TextView，但你想，因为它只是一个常规的TextView。在你的activity中，你可以像这样访问标题:

Toolbar toolbarTop = (Toolbar) findViewById(R.id.toolbar_top);
TextView mTitle = (TextView) toolbarTop.findViewById(R.id.toolbar_title);

工具栏标题是可设置样式的。你所做的任何定制都必须在主题中进行。我给你们举个例子。

工具栏布局:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar
    style="@style/ToolBarStyle.Event"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/colorPrimary"
    android:minHeight="@dimen/abc_action_bar_default_height_material" />

风格:

<style name="ToolBarStyle" parent="ToolBarStyle.Base"/>

<style name="ToolBarStyle.Base" parent="">
    <item name="popupTheme">@style/ThemeOverlay.AppCompat.Light</item>
    <item name="theme">@style/ThemeOverlay.AppCompat.Dark.ActionBar</item>
</style>

<style name="ToolBarStyle.Event" parent="ToolBarStyle">
    <item name="titleTextAppearance">@style/TextAppearance.Widget.Event.Toolbar.Title</item>
</style>

<style name="TextAppearance.Widget.Event.Toolbar.Title" parent="TextAppearance.Widget.AppCompat.Toolbar.Title">
    <!--Any text styling can be done here-->
    <item name="android:textStyle">normal</item>
    <item name="android:textSize">@dimen/event_title_text_size</item>
</style>

尝试在单独的视图中使用工具栏和标题。在右端取一个视图，并赋予它们等于工具栏权重的权重。这样你的小个子就会放在中间。

<android.support.design.widget.AppBarLayout
    android:id="@+id/app_bar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay"
    android:background="@color/white_color">
  <LinearLayout
   android:id="@+id/toolbar_layout"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:background="@color/white_color">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="0dp"
        android:layout_height="?attr/actionBarSize"
        android:background="@color/white_color"
        app:popupTheme="@style/AppTheme.PopupOverlay"
        app:contentInsetLeft="0dp"
        app:contentInsetStart="0dp"
        android:layout_weight="0.2"

        app:contentInsetStartWithNavigation="0dp"
        app:navigationIcon="@color/greyTextColor">
       </android.support.v7.widget.Toolbar>


        <com.an.customfontview.CustomTextView
            android:id="@+id/headingText"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="0.6"
            android:gravity="center"
            android:text="Heading"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true"
            android:textColor="@color/colorPrimary"
            android:textSize="@dimen/keyboard_number"
            android:layout_gravity="center_horizontal|center_vertical"
            app:textFontPath="fonts/regular.ttf" />
            <ImageView
                android:id="@+id/search_icon"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_alignParentEnd="true"
                android:layout_centerVertical="true"
                android:visibility="visible"
                android:layout_weight="0.2"
                android:layout_gravity="center_horizontal|center_vertical"
                android:src="@drawable/portfolio_icon"/>
        </LinearLayout>

       </android.support.design.widget.AppBarLayout>

没有工具栏TextView，我们可以自定义字体使用下面的代码

getSupportActionBar().setDisplayShowTitleEnabled(false);
or
getActionBar().setDisplayShowTitleEnabled(false);

public void updateActionbar(String title){
    SpannableString spannableString = new SpannableString(title);
    spannableString.setSpan(new TypefaceSpanString(this,  "futurastdmedium.ttf"),
            0, spannableString.length(),
            Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
    mToolbar.setTitle(spannableString);
}

这是我用一个导航图标和一个文本视图所做的 现在您可以进行扩展，以便在任何需要的地方应用它。但你必须把它应用到每一项活动中

(toolbar[0] as AppCompatTextView).let {
            it.viewTreeObserver.addOnDrawListener {
                it.layoutParams = it.layoutParams.apply {
                    width = Toolbar.LayoutParams.MATCH_PARENT
                    (this as ViewGroup.MarginLayoutParams).apply {
                        marginEnd = toolbar[1].width
                    }
                }
                it.textAlignment = View.TEXT_ALIGNMENT_CENTER
            }

        }

    public class TestActivity extends AppCompatActivity {
    private Toolbar toolbar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.setContentView(R.layout.activity_test);

        toolbar = (Toolbar) findViewById(R.id.tool_bar); // Attaching the layout to the toolbar object
        setSupportActionBar(toolbar);

        customizeToolbar(toolbar);
    }

    public void customizeToolbar(Toolbar toolbar){
        // Save current title and subtitle
        final CharSequence originalTitle = toolbar.getTitle();
        final CharSequence originalSubtitle = toolbar.getSubtitle();

        // Temporarily modify title and subtitle to help detecting each
        toolbar.setTitle("title");
        toolbar.setSubtitle("subtitle");

        for(int i = 0; i < toolbar.getChildCount(); i++){
            View view = toolbar.getChildAt(i);

            if(view instanceof TextView){
                TextView textView = (TextView) view;


                if(textView.getText().equals("title")){
                    // Customize title's TextView
                    Toolbar.LayoutParams params = new Toolbar.LayoutParams(Toolbar.LayoutParams.WRAP_CONTENT, Toolbar.LayoutParams.MATCH_PARENT);
                    params.gravity = Gravity.CENTER_HORIZONTAL;
                    textView.setLayoutParams(params);

                    // Apply custom font using the Calligraphy library
                    Typeface typeface = TypefaceUtils.load(getAssets(), "fonts/myfont-1.otf");
                    textView.setTypeface(typeface);

                } else if(textView.getText().equals("subtitle")){
                    // Customize subtitle's TextView
                    Toolbar.LayoutParams params = new Toolbar.LayoutParams(Toolbar.LayoutParams.WRAP_CONTENT, Toolbar.LayoutParams.MATCH_PARENT);
                    params.gravity = Gravity.CENTER_HORIZONTAL;
                    textView.setLayoutParams(params);

                    // Apply custom font using the Calligraphy library
                    Typeface typeface = TypefaceUtils.load(getAssets(), "fonts/myfont-2.otf");
                    textView.setTypeface(typeface);
                }
            }
        }

        // Restore title and subtitle
        toolbar.setTitle(originalTitle);
        toolbar.setSubtitle(originalSubtitle);
    }
}