ToolBar使用详解

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注意：使用ToolBar的话，一定要将当前Activity或者Application的Theme设置为NoActionBar样式，如<style name=”AppTheme” parent=”Theme.AppCompat.Light.NoActionBar”>,否则ActionBar和ToolBar两者都会显示，而且setSupportActionBar方法将会抛出异常，其实使用了ToolBar完全可以把ActionBar抛到一边去，只是使用ToolBar就能完成所有ActionBar的功能。

    ToolBar是在Android5.0中提出来的，ActionBar在Android3.0提出来的。ActionBar是系统为我们创建一个View并显示在应用的顶端，直接继承自Object，因此我们如果要对这块内容的视图进行定制就需要严格按照ActionBar的方式进行工作。ToolBar是一个继承自ViewGroup的控件，因此我们可以用ViewGroup的方式去创建任何我们想要的视图内容，也可在布局文件中写入我们想要的内容，因此ToolBar比ActionBar更加灵活。同时ToolBar相对于ViewGroup的好处在于，提供了更多便捷的方法来控制显示方式，这些方式主要是针对标题栏的特性而定制的，比如我们可以通过setTitle方法为其设置标题。下图是网上找的Toolbar提供的便捷方法所对应的修改的内容：

上图对应方法有：toolbar.setTitle(“AndroidViewDemo”); 、toolbar.inflateMenu(R.menu.ac_toolbar_menu); 、toolbar.setOnMenuItemClickListener(new Toolbar.OnMenuItemClickListener() {…}等。

    Toolbar与ActionBar一样也支持对弹出菜单样式的修改，只不过在将Toolbar单独作为控件使用的情况下不能像ActionBar那样便捷地通过Theme来修改，Toolbar提供了一个setPopupTheme方法和对应的app.popupTheme属性来设置弹出菜单的样式。

    标题栏本身就是一个特殊的View为何不然View自己来处理呢？所以还是建议使用ToolBar的。如果你习惯了ActionBar那么你也可以在创建完Toolbar之后通过setSupportActionBar方法将Toolbar设置为当前Activity的ActionBar，之后的所有操作跟ActionBar都是一样的了。

简单使用：

一、编写菜单栏布局（标题栏右边最多显示三个Action，其余则隐藏）

menu_main.xml

<menu xmlns:android=“http://schemas.android.com/apk/res/android”
    xmlns:app=“http://schemas.android.com/apk/res-auto”>
    <item
        android:id=“@+id/menu_tool”
        android:icon=“@drawable/toolbar1”
        app:showAsAction=“ifRoom”
        android:orderInCategory=“50”
        android:title=“Tool”>
    </item>
    <item
        android:id=“@+id/menu_finder”
        android:icon=“@drawable/toolbar2”
        app:showAsAction=“ifRoom”
        android:orderInCategory=“10”
        android:title=“Find”>
    </item>
</menu>

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/menu_tool"
        android:icon="@drawable/toolbar1"
        app:showAsAction="ifRoom"
        android:orderInCategory="50"
        android:title="Tool">
    </item>
    <item
        android:id="@+id/menu_finder"
        android:icon="@drawable/toolbar2"
        app:showAsAction="ifRoom"
        android:orderInCategory="10"
        android:title="Find">
    </item>
</menu>

注意：

    android:title=”XX”属性用于设置当该item在overflow menu显示时显示的文字内容。app:showAsAction=”ifRoom”  用于设置在有足够空间的情况下在toolbar中显示Action的图标。

二、main_activity.xml布局文件中加入<Toolbar/>标签

<android.support.v7.widget.Toolbar xmlns:android=“http://schemas.android.com/apk/res/android”
    xmlns:app=“http://schemas.android.com/apk/res-auto”
    android:id=“@+id/toolbar”
    android:layout_width=“match_parent”
    android:layout_height=“wrap_content”
    android:minHeight=“?attr/actionBarSize”
    android:background=“?attr/colorPrimary”
    app:contentInsetStart=“0dp”
    app:contentInsetLeft=“0dp”
    app:theme=“@style/MyToolBarTheme”
    app:titleTextAppearance=“@style/Toolbar.TitleText”
    >
    <!–此处可以加你想要的View控件，如同LinearLayout类似的使用–>
</android.support.v7.widget.Toolbar>

<!–android:contentInsertStart  contentInsetLeft是没有效果的不能保证控件靠近左边显示–>

<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:minHeight="?attr/actionBarSize"
    android:background="?attr/colorPrimary"
    app:contentInsetStart="0dp"
    app:contentInsetLeft="0dp"
    app:theme="@style/MyToolBarTheme"
    app:titleTextAppearance="@style/Toolbar.TitleText"
    >
    <!--此处可以加你想要的View控件，如同LinearLayout类似的使用-->
</android.support.v7.widget.Toolbar>

<!--android:contentInsertStart  contentInsetLeft是没有效果的不能保证控件靠近左边显示-->

ToolBar在此可以就看成一个普通的ViewGroup，因此它显示的位置可以随意设置，但是如果要模拟ActionBar的功能，则需要将其放置在视图的最顶部。

 三、Activity中获取ToolBar控件并做相应设置

1、初始化

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        toolbar = (Toolbar)findViewById(R.id.toolbar);
        toolbar.setNavigationIcon(R.mipmap.back);
        //设置标题栏左边的图标样式，对应id为android.id.home ，用于返回上一级目录
        setSupportActionBar(toolbar);
        //将ToolBar对象设置为当前Activity的ActionBar
}

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        toolbar = (Toolbar)findViewById(R.id.toolbar);
        toolbar.setNavigationIcon(R.mipmap.back); 
        //设置标题栏左边的图标样式，对应id为android.id.home ，用于返回上一级目录
        setSupportActionBar(toolbar);
        //将ToolBar对象设置为当前Activity的ActionBar
}

2、加载显示Menu布局，重写Activity的onCreateOptionMenu方法

@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
}

@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
}

3、监听标题栏中的点击事件

@Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()){
            case R.id.menu_finder:
                Toast.makeText(MainActivity.this,“touch finderItem”,Toast.LENGTH_SHORT).show();
                AndroidUtils.changeActivity(this,SearchActivity.class); //跳转到搜索页Activity
                break;
            case R.id.menu_tool:
                Toast.makeText(MainActivity.this,“touch toolItem”,Toast.LENGTH_SHORT).show();
                AndroidUtils.showPopupMenu(this,toolbar,R.menu.popmenu,new OnPopupMenuItemClickListener(this)); //弹出共享菜单
                break;
            case android.R.id.home:
                Toast.makeText(MainActivity.this,“touch up navigation”,Toast.LENGTH_SHORT).show();
                AndroidUtils.backToParent(this); //返回上一级目录
                break;
            default: return super.onOptionsItemSelected(item);
        }
        return true;
}
    /**
     * 弹出共享菜单
     */
     public static void showPopupMenu(Context context,
                                     View v,int menuResId, PopupMenu.OnMenuItemClickListener onMenuItemClickListener,
                                     PopupMenu.OnDismissListener onDismissListener,int gravity){
        PopupMenu popup = new PopupMenu(context, v);
        MenuInflater inflater = popup.getMenuInflater();
        inflater.inflate(menuResId, popup.getMenu());
        //利用反射显示图标
        try {
            Field field = popup.getClass().getDeclaredField(”mPopup”);
            field.setAccessible(true);
            MenuPopupHelper mHelper = (MenuPopupHelper) field.get(popup);
            mHelper.setForceShowIcon(true);
        } catch (IllegalAccessException | NoSuchFieldException e) {
            e.printStackTrace();   }
        popup.setOnMenuItemClickListener(onMenuItemClickListener);
        if(onDismissListener!=null) popup.setOnDismissListener(onDismissListener);
        popup.setGravity(gravity);
        popup.show();
    }
    /**
     * 跳转到父Activity
     */
    public static void backToParent(Activity activity){
        Intent upIntent = NavUtils.getParentActivityIntent(activity);
        if(upIntent == null) {
            activity.finish();
            return;
        }
        if (NavUtils.shouldUpRecreateTask(activity, upIntent)) {
            // This activity is NOT part of this app’s task, so create a new task
            // when navigating up, with a synthesized back stack.
            TaskStackBuilder.create(activity)
                    // Add all of this activity’s parents to the back stack
                    .addNextIntentWithParentStack(upIntent)
                            // Navigate up to the closest parent
                    .startActivities();
        } else {
            // This activity is part of this app’s task, so simply
            // navigate up to the logical parent activity.
            NavUtils.navigateUpTo(activity, upIntent);
        }
    }

@Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()){
            case R.id.menu_finder:
                Toast.makeText(MainActivity.this,"touch finderItem",Toast.LENGTH_SHORT).show();
                AndroidUtils.changeActivity(this,SearchActivity.class); //跳转到搜索页Activity
                break;
            case R.id.menu_tool:
                Toast.makeText(MainActivity.this,"touch toolItem",Toast.LENGTH_SHORT).show();
                AndroidUtils.showPopupMenu(this,toolbar,R.menu.popmenu,new OnPopupMenuItemClickListener(this)); //弹出共享菜单
                break;
            case android.R.id.home:
                Toast.makeText(MainActivity.this,"touch up navigation",Toast.LENGTH_SHORT).show();
                AndroidUtils.backToParent(this); //返回上一级目录
                break;
            default: return super.onOptionsItemSelected(item);
        }
        return true;
}
    /**
     * 弹出共享菜单
     */
     public static void showPopupMenu(Context context,
                                     View v,int menuResId, PopupMenu.OnMenuItemClickListener onMenuItemClickListener,
                                     PopupMenu.OnDismissListener onDismissListener,int gravity){
        PopupMenu popup = new PopupMenu(context, v);
        MenuInflater inflater = popup.getMenuInflater();
        inflater.inflate(menuResId, popup.getMenu());
        //利用反射显示图标
        try {
            Field field = popup.getClass().getDeclaredField("mPopup");
            field.setAccessible(true);
            MenuPopupHelper mHelper = (MenuPopupHelper) field.get(popup);
            mHelper.setForceShowIcon(true);
        } catch (IllegalAccessException | NoSuchFieldException e) {
            e.printStackTrace();   }
        popup.setOnMenuItemClickListener(onMenuItemClickListener);
        if(onDismissListener!=null) popup.setOnDismissListener(onDismissListener);
        popup.setGravity(gravity);
        popup.show();
    }
    /**
     * 跳转到父Activity
     */
    public static void backToParent(Activity activity){
        Intent upIntent = NavUtils.getParentActivityIntent(activity);
        if(upIntent == null) {
            activity.finish();
            return;
        }
        if (NavUtils.shouldUpRecreateTask(activity, upIntent)) {
            // This activity is NOT part of this app's task, so create a new task
            // when navigating up, with a synthesized back stack.
            TaskStackBuilder.create(activity)
                    // Add all of this activity's parents to the back stack
                    .addNextIntentWithParentStack(upIntent)
                            // Navigate up to the closest parent
                    .startActivities();
        } else {
            // This activity is part of this app's task, so simply
            // navigate up to the logical parent activity.
            NavUtils.navigateUpTo(activity, upIntent);
        }
    }

注意： NavUtils 类的静态方法navigateUpFromSameTask()的效果是：finishes当前Activity并start或者resume其父Activity，如果父Activity在任务的返回栈中，那么正常回退。注意该方法仅仅适用于当当前应用是当前任务的所有者时方可使用。如果当前应用不是当前任务的所有者时，需要建立一个新的返回栈，如果你Activity能够接受其它应用通过Intent开启你的Activity，那么就需要注意这样的处理，具体内容就是第三步的case android.R.id.home下面的内容。如果你期望回退到父Activity时，其还能保持原来的状态，那么父Activity可能需要设置启动方式为android:launchMode=”singleTop”。

 （补充）四、Fragment中使用ToolBar

@Override  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // …
    setHasOptionsMenu(true);
}
@Override  public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    // Inflate the menu; this adds items to the action bar.
    inflater.inflate(R.menu.my_menu, menu);
    // …
}
@Override  public boolean onOptionsItemSelected(MenuItem item) {
   // handle item selection
   switch (item.getItemId()) {
      case R.id.my_item:
         // Handle this selection
         return true;
      default:
         return super.onOptionsItemSelected(item);
   }
}

@Override  public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState);
    // ...
    setHasOptionsMenu(true);
}
@Override  public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { 
    // Inflate the menu; this adds items to the action bar.
    inflater.inflate(R.menu.my_menu, menu);  
    // ...
}
@Override  public boolean onOptionsItemSelected(MenuItem item) { 
   // handle item selection
   switch (item.getItemId()) {
      case R.id.my_item:
         // Handle this selection
         return true;
      default:
         return super.onOptionsItemSelected(item);
   }
}

可以发现Fragment除了第一步之外其它都是和Activity类似的。

（补充）五、ToolBar的Style设定

ToolBar的构造器中有如下一行语句：

final TintTypedArray a = TintTypedArray.obtainStyledAttributes(getContext(), null,  R.styleable.Toolbar, R.attr.toolbarStyle, 0);方法底层会调用TypedArray array = context.obtainStyledAttributes(null,   R.styleable.Toolbar, R.attr.toolbarStyle, 0);即从主题中定义的toolbarStyle样式文件中和主题直接定义的属性中获取到如下属性：

<declare-styleable name=“Toolbar”>
    <attr format=“reference” name=“titleTextAppearance”/>
    <attr format=“reference” name=“subtitleTextAppearance”/>
    <attr name=“title”/>
    <attr name=“subtitle”/>
    <attr name=“android:gravity”/>
    <attr format=“dimension” name=“titleMargins”/>
    <attr format=“dimension” name=“titleMarginStart”/>
    <attr format=“dimension” name=“titleMarginEnd”/>
    <attr format=“dimension” name=“titleMarginTop”/>
    <attr format=“dimension” name=“titleMarginBottom”/>
    <attr name=“contentInsetStart”/>
    <attr name=“contentInsetEnd”/>
    <attr name=“contentInsetLeft”/>
    <attr name=“contentInsetRight”/>
    <attr format=“dimension” name=“maxButtonHeight”/>
    <attr format=“reference” name=“collapseIcon”/>
    <attr format=“string” name=“collapseContentDescription”/>
    <attr name=“Theme”/> <!–这里可以修改ToolBar除了PopupMenu的所有信息（如背景色：注意java代码中的setBackgroundColor这个方法不要用存在bug！！！效果不好，使用这里的background属性进行设置） 设置的值可以参考主题ThemeOverlay.AppCompat.Dark.ActionBar–>
    <attr name=“popupTheme”/>  <!–这里只能修改由ToolBar创建的弹出菜单，而对于自己通过创建PopupMenu对象显示的只能通过对context设置对应的主题进行设置，设置的值可以参考ThemeOverlay.AppCompat.Light–>
    <attr format=“reference” name=“navigationIcon”/>
    <attr format=“string” name=“navigationContentDescription”/>
    <attr name=“android:minHeight”/>
    <attr name=“logo”/>
    <attr format=“string” name=“logoDescription”/>
    <attr format=“color” name=“titleTextColor”/>
    <attr format=“color” name=“subtitleTextColor”/>
</declare-styleable>

<declare-styleable name="Toolbar">
    <attr format="reference" name="titleTextAppearance"/>
    <attr format="reference" name="subtitleTextAppearance"/>
    <attr name="title"/>
    <attr name="subtitle"/>
    <attr name="android:gravity"/>
    <attr format="dimension" name="titleMargins"/>
    <attr format="dimension" name="titleMarginStart"/>
    <attr format="dimension" name="titleMarginEnd"/>
    <attr format="dimension" name="titleMarginTop"/>
    <attr format="dimension" name="titleMarginBottom"/>
    <attr name="contentInsetStart"/>
    <attr name="contentInsetEnd"/>
    <attr name="contentInsetLeft"/>
    <attr name="contentInsetRight"/>
    <attr format="dimension" name="maxButtonHeight"/>
    <attr format="reference" name="collapseIcon"/>
    <attr format="string" name="collapseContentDescription"/>
    <attr name="Theme"/> <!--这里可以修改ToolBar除了PopupMenu的所有信息（如背景色：注意java代码中的setBackgroundColor这个方法不要用存在bug！！！效果不好，使用这里的background属性进行设置） 设置的值可以参考主题ThemeOverlay.AppCompat.Dark.ActionBar-->
    <attr name="popupTheme"/>  <!--这里只能修改由ToolBar创建的弹出菜单，而对于自己通过创建PopupMenu对象显示的只能通过对context设置对应的主题进行设置，设置的值可以参考ThemeOverlay.AppCompat.Light-->
    <attr format="reference" name="navigationIcon"/>
    <attr format="string" name="navigationContentDescription"/>
    <attr name="android:minHeight"/>
    <attr name="logo"/>
    <attr format="string" name="logoDescription"/>
    <attr format="color" name="titleTextColor"/>
    <attr format="color" name="subtitleTextColor"/>
</declare-styleable>

深入分析：

public class Toolbar extends ViewGroup

Toolbar()@Toolbar.class

public Toolbar(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        // Need to use getContext() here so that we use the themed context
        final TintTypedArray a = TintTypedArray.obtainStyledAttributes(getContext(), attrs,  R.styleable.Toolbar, defStyleAttr, 0);
        mTitleTextAppearance = a.getResourceId(R.styleable.Toolbar_titleTextAppearance, 0);
        ……//get操作
        final CharSequence title = a.getText(R.styleable.Toolbar_title);
        if (!TextUtils.isEmpty(title)) {
            setTitle(title);
        }

        final CharSequence subtitle = a.getText(R.styleable.Toolbar_subtitle);
        if (!TextUtils.isEmpty(subtitle)) {
            setSubtitle(subtitle);
        }
        …..//set操作
}

public Toolbar(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        // Need to use getContext() here so that we use the themed context
        final TintTypedArray a = TintTypedArray.obtainStyledAttributes(getContext(), attrs,  R.styleable.Toolbar, defStyleAttr, 0); 
        mTitleTextAppearance = a.getResourceId(R.styleable.Toolbar_titleTextAppearance, 0);
        ......//get操作
        final CharSequence title = a.getText(R.styleable.Toolbar_title);
        if (!TextUtils.isEmpty(title)) {
            setTitle(title);
        }

        final CharSequence subtitle = a.getText(R.styleable.Toolbar_subtitle);
        if (!TextUtils.isEmpty(subtitle)) {
            setSubtitle(subtitle);
        }
        .....//set操作
}

构造器除了调用ViewGroup的构造器之外，还会获取当前View所属Context的主题相关的属性。

onMeasure()@Toolbar.class

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = 0;
        int height = 0;
        int childState = 0;
        ………//note1
        final int measuredWidth = ViewCompat.resolveSizeAndState(
                Math.max(width, getSuggestedMinimumWidth()),
                widthMeasureSpec, childState & ViewCompat.MEASURED_STATE_MASK);
        final int measuredHeight = ViewCompat.resolveSizeAndState(
                Math.max(height, getSuggestedMinimumHeight()),
                heightMeasureSpec, childState << ViewCompat.MEASURED_HEIGHT_STATE_SHIFT);

        setMeasuredDimension(measuredWidth, shouldCollapse() ? 0 : measuredHeight);
}

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = 0;
        int height = 0;
        int childState = 0;
        .........//note1
        final int measuredWidth = ViewCompat.resolveSizeAndState(
                Math.max(width, getSuggestedMinimumWidth()),
                widthMeasureSpec, childState & ViewCompat.MEASURED_STATE_MASK);
        final int measuredHeight = ViewCompat.resolveSizeAndState(
                Math.max(height, getSuggestedMinimumHeight()),
                heightMeasureSpec, childState << ViewCompat.MEASURED_HEIGHT_STATE_SHIFT);

        setMeasuredDimension(measuredWidth, shouldCollapse() ? 0 : measuredHeight);
}

1、根据Toolbar中子View设置当前Toolbar显示高度宽度。

onLayout()@Toolbar.class

protected void onLayout(boolean changed, int l, int t, int r, int b) {
        final boolean isRtl =  ViewCompat.getLayoutDirection(this) ==  ViewCompat.LAYOUT_DIRECTION_RTL;
        //Horizontal layout direction of this view is from Right to Left.
        final int width = getWidth();
        final int height = getHeight();
        final int paddingLeft = getPaddingLeft();
        final int paddingRight = getPaddingRight();
        final int paddingTop = getPaddingTop();
        final int paddingBottom = getPaddingBottom();
        int left = paddingLeft;
        int right = width - paddingRight;
        ….
        if (shouldLayout(mNavButtonView)) {….}
        if (shouldLayout(mCollapseButtonView)) {….}
        if (shouldLayout(mMenuView)) {….}
        ….

       addCustomViewsWithGravity(mTempViews, Gravity.LEFT);
        //ArrayList<View> mTempViews = new ArrayList<View>();
        final int leftViewsCount = mTempViews.size();
        for (int i = 0; i < leftViewsCount; i++) {
            left = layoutChildLeft(mTempViews.get(i), left, collapsingMargins,
                    alignmentHeight);
        }

        addCustomViewsWithGravity(mTempViews, Gravity.RIGHT);{…… }
        addCustomViewsWithGravity(mTempViews, Gravity.CENTER_HORIZONTAL);{…… }
        mTempViews.clear();
}

protected void onLayout(boolean changed, int l, int t, int r, int b) {
        final boolean isRtl =  ViewCompat.getLayoutDirection(this) ==  ViewCompat.LAYOUT_DIRECTION_RTL;
        //Horizontal layout direction of this view is from Right to Left.
        final int width = getWidth();
        final int height = getHeight();
        final int paddingLeft = getPaddingLeft();
        final int paddingRight = getPaddingRight();
        final int paddingTop = getPaddingTop();
        final int paddingBottom = getPaddingBottom();
        int left = paddingLeft;
        int right = width - paddingRight;
        ....
        if (shouldLayout(mNavButtonView)) {....}
        if (shouldLayout(mCollapseButtonView)) {....}
        if (shouldLayout(mMenuView)) {....}
        ....

       addCustomViewsWithGravity(mTempViews, Gravity.LEFT);
        //ArrayList<View> mTempViews = new ArrayList<View>();
        final int leftViewsCount = mTempViews.size();
        for (int i = 0; i < leftViewsCount; i++) {
            left = layoutChildLeft(mTempViews.get(i), left, collapsingMargins,
                    alignmentHeight);
        }

        addCustomViewsWithGravity(mTempViews, Gravity.RIGHT);{...... } 
        addCustomViewsWithGravity(mTempViews, Gravity.CENTER_HORIZONTAL);{...... } 
        mTempViews.clear();
}

方法先对Toolbar中的导航栏、菜单栏、logo和标题等ActionBar中的属性进行布局。最后才给自己的childView进行布局。

Reference：http://blog.csdn.net/aigestudio/article/details/47090167