如何使用导航抽屉打开和关闭更改按钮图像

Posted 2023-04-19

【中文标题】如何使用导航抽屉打开和关闭更改按钮图像

【英文标题】：How do I change my button image with navigation drawer opening and closing

【发布时间】：2013-12-13 07:26:55

【问题描述】：

我的导航片段有一个导航按钮，该按钮变为活动状态并在单击时打开一个导航抽屉菜单：

现在，当我单击它时，它会变为活动状态，如下所示：

但是，我想将它与导航抽屉相关联，这样，即使我没有单击按钮并滑动打开导航抽屉，当导航抽屉菜单打开时，按钮也会在通过滑动关闭时变为活动状态从右到左返回，按钮变为红色/无效。我正在尝试使用的代码如下：

private boolean mIsNavigationOpen = false;
    private DrawerLayout drawerLayout;
    private NavigationPanelFragment dlDrawer;
    private ActionBarDrawerToggle actionBarDrawerToggle;
public boolean isNavigationOpen() 

        return mIsNavigationOpen;

    
//----------Code for Navigation open logo button active/inactive instances
    @SuppressWarnings("deprecation")
    public void setNavigationOpen(final boolean isNavigationOpen) 
        this.mIsNavigationOpen = isNavigationOpen;
        final ImageButton mainButton = (ImageButton) findViewById(R.id.button_main);
        if(isNavigationOpen) 
            mainButton.setBackgroundResource(R.drawable.bg_helios_active);
         else 
            mainButton.setBackgroundDrawable(null);
        
@Override
    protected void onCreate(final Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_activity);
        //----------Code for Navigation Drawer setup
        // 2. App Icon 
        drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        // 2.1 create ActionBarDrawerToggle
                 actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout,
                            R.drawable.arrow_up, R.string.drawer_open, R.string.drawer_close)

                        /** Called when a drawer has settled in a completely closed state. */
                        public void onDrawerClosed(View view) 
                           // getActionBar().setTitle(NavigationPanelFragment.activeFragmentTitle);
                           // invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
                        

                        /** Called when a drawer has settled in a completely open state. */
                        public void onDrawerOpened(View drawerView) 
                         //   getActionBar().setTitle(NavigationPanelFragment.activeFragmentTitle);
                          //  invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
                        
                    ;


                // 2.2 Set actionBarDrawerToggle as the DrawerListener
                drawerLayout.setDrawerListener(actionBarDrawerToggle);
          
@Override
    protected void onPostCreate(Bundle savedInstanceState) 
        super.onPostCreate(savedInstanceState);
        // Sync the toggle state after onRestoreInstanceState has occurred.
         actionBarDrawerToggle.syncState();
    
private void setupOnClickListenerForMainButton() 
        final ImageButton mainButton = (ImageButton) findViewById(R.id.button_main);
        mainButton.setOnClickListener(new OnClickListener() 

            @Override
            public void onClick(final View v) 
                toggleNavigationPanel();


            
        );
    
@Override
    public boolean onMenuItemSelected(final int featureId, final MenuItem item) 
        switch (item.getItemId()) 
            case android.R.id.home:
                toggleNavigationPanel();
                break;

            default:
                break;
        
        return super.onMenuItemSelected(featureId, item);
    
public void onNewsClicked(final View view) 
        if(mIsNavigationOpen) 
            toggleNavigationPanel();
        

        if (isFragmentVisible(NewsFragment.TAG_NEWS_FRAGMENT)) 
            return;
        

        FragmentStackManager.getInstance().clearBackStack(getSupportFragmentManager());
        mActiveFragment = NewsFragment.newInstance(getSupportFragmentManager());
        updateActionBarTitle();
        //For swipe action close drawer on button click
         drawerLayout.closeDrawer(R.id.drawer);
    
public void onListsClicked(final View view) 
        if(mIsNavigationOpen) 
            toggleNavigationPanel();
        

        if (isFragmentVisible(ListsContainerFragment.TAG_LIST_CONTAINER_FRAGMENT)) 
            return;
        

        FragmentStackManager.getInstance().clearBackStack(getSupportFragmentManager());
        mActiveFragment = ListsContainerFragment.newInstance(getSupportFragmentManager());
        updateActionBarTitle();
        //For swipe action close drawer on button click
        drawerLayout.closeDrawer(R.id.drawer);
    
private void toggleNavigationPanel() 
        //final FragmentStackManager manager = FragmentStackManager.getInstance();
        if (mIsNavigationOpen) 
            //NavigationPanelFragment.removeInstance(getSupportFragmentManager());
            updateActionBarTitle();
            drawerLayout.closeDrawer(R.id.drawer);
         else 
            drawerLayout.openDrawer(R.id.drawer);
            final TextView title = (TextView) findViewById(R.id.main_title);
            title.setText(getString(R.string.title_applications));
            //NavigationPanelFragment.newInstance(getSupportFragmentManager(), manager.getTopTitle());
        


        setNavigationOpen(!mIsNavigationOpen);
    

您可能希望专注于 main_button 和 togglenavigationpanel。我添加了条件 if(drawerlayout.isdraweropen(R.id.drawer))closedrawerlayout... 但它没有成功。我想知道是否有人对此有任何想法？

谢谢！

【问题讨论】：

你为什么不使用onDrawerClosed和onDrawerOpened？

如何使用它？能用代码说明一下吗？

另外，我添加了 public void onDrawerClosed(View view) toggleNavigationPanel()public void onDrawerOpened(ViewdrawerView) toggleNavigationPanel() 它适用于滑动但 onclick 它因空指针异常而崩溃

【参考方案1】：

当您设置抽屉时，添加了一个侦听器，该侦听器具有当抽屉处于任一最终状态时的回调，因此您需要做的是在这些回调中重置可绘制对象。我已经展示了我认为你的最终代码应该是什么样子，减去你需要做的一些清理工作，希望它有所帮助

private DrawerLayout drawerLayout;
private NavigationPanelFragment dlDrawer;
private ActionBarDrawerToggle actionBarDrawerToggle;
private ImageButton mDrawerButton; //Store it! - findViewById is *Expensive*
private TextView mTitle;

@Override
protected void onCreate(final Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_activity);
    mTitle = (TextView) findViewById(R.id.main_title);
    mDrawerButton = (ImageButton) findViewById(R.id.button_main);
    drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout,
            R.drawable.arrow_up, R.string.drawer_open, R.string.drawer_close) 

        public void onDrawerClosed(View view) 
            mDrawerButton.setImageResource(R.drawable.bg_helios_inactive);
        

        public void onDrawerOpened(View drawerView) 
            mDrawerButton.setImageResource(R.drawable.bg_helios_active);
        

    ;
    drawerLayout.setDrawerListener(actionBarDrawerToggle);
    setupOnClickListenerForMainButton(;


@Override //Note: I'd imagine this should be in onResume ...
protected void onPostCreate(Bundle savedInstanceState) 
    super.onPostCreate(savedInstanceState);
    actionBarDrawerToggle.syncState();


private void setupOnClickListenerForMainButton() 
    mDrawerButton.setOnClickListener(new OnClickListener() 
        @Override
        public void onClick(final View v) 
            toggleNavigationPanel();
        
    );


...

private void toggleNavigationPanel() 
    //if ( drawerLayout.isOpen() )  //I dont know what methods these objects have
    if ( dlDrawer.isOpen() )  //but one of these must be sensibly storing its own state
        updateActionBarTitle();
        drawerLayout.closeDrawer(R.id.drawer);
     else 
        drawerLayout.openDrawer(R.id.drawer);
        mTitle.setText(getString(R.string.title_applications));
    

【讨论】：

它似乎在 mDrawerButton.setImageResource(R.drawable.bg_helios_active);有一个空指针异常。但是，当我回到我的原始实现并在 Oncreate 的 onDrawerOpened/Ondrawerclosed 中添加 toggleNavigationPanel() 时，它确实识别了导航抽屉的滑动并将 helios 按钮切换为选中和取消选中，但只要我点击 helios button ，它崩溃了一个空指针异常，我想知道是什么导致了崩溃

如果您在由 toggleNavigationPanel() 的操作触发的回调中有 toggleNavigationPanel()，它将如何工作？确保在 oncreate (mDrawerButton) 中找到图像视图并查看您的 logcat 以获取更多信息

我也需要为按钮的点击保留 isNavigationOpen() 函数，所以我将条件定义为 if ( isNavigationOpen() ||drawerLayout.isDrawerOpen(R.id.drawer) ) updateActionBarTitle();抽屉布局.closeDrawer(R.id.drawer); else 抽屉布局.openDrawer(R.id.drawer); mTitle.setText(getString(R.string.title_applications)); ?

保留该变量是自找麻烦，因为抽屉应该知道它的状态，然后您还要存储一个单独的状态表示，这可能会不同步。使用（或在必要时添加）抽屉状态和 isDrawerOpen 方法。 drawLayout.closeDrawer 和 openDrawer 应该更新状态，因此绝对没有理由将其存储在这里，脱离上下文

即使我更改所有内容并将任何内容放在 public void onDrawerClosed(View view) 中，它也会在 android.support.v4.widget.DrawerLayout.updateDrawerState(DrawerLayout.java:459) 处因空指针异常而崩溃在 android.support.v4.widget.DrawerLayout$ViewDragCallback.onViewDragStateChanged(DrawerLayout.java:1348) 在 android.support.v4.widget.ViewDragHelper.setDragState(ViewDragHelper.java:866) 在 android.support.v4.widget.ViewDragHelper $2.run(ViewDragHelper.java:335) 在 android.os.Handler.handleCallback(Handler.java:615) 在 android.os.Handler.dispatchMessage(Handler.java:92)