“返回按钮"使用getSupportActionbar和appcompat v7工具栏

问题描述

我正在使用Appcompat V7库中的新工具栏，并且正在制作带有导航抽屉和片段的应用程序.

I'm using the new toolbar from the Appcompat V7 library and I'm making an application with navigation drawer and with fragments.

在某些片段中，我不想显示汉堡包图标，而是显示箭头...很好，我这样做是这样的:

In some fragments I don't want to show the hamburger icon but the arrow instead... That is fine I did this in this way:

mDrawerToggle.setDrawerIndicatorEnabled(false);

mDrawerToggle.syncState();
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);

getSupportActionBar().setHomeAsUpIndicator(R.drawable.abc_ic_ab_back_mtrl_am_alpha);

我的问题是:如何或在何处设置主页按钮lisener或需要听后退"按钮的内容?我想调用主要的backpressed方法，并用汉堡包图标调回导航抽屉图标.

My question is that: How or where i need to set up the home button lisener or what i need to listen for the "back" button ?I want to call the main backpressed method and to set back the navigation drawer icon with the hamburger icon..

推荐答案

您可以这样做:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    toolbar = (Toolbar)findViewById(R.id.toolbar);
    if (toolbar != null) {
      setSupportActionBar(toolbar);
      getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    }

    setUpNavigationDrawer();

    getFragmentManager().addOnBackStackChangedListener(backStackListener); // listen to the backstack of the fragment manager
}

定义onBackSTackChangedListener:

Define the onBackSTackChangedListener:

private FragmentManager.OnBackStackChangedListener backStackListener = new FragmentManager.OnBackStackChangedListener() {
   @Override
   public void onBackStackChanged() {
       setNavIcon();
   };
}

根据片段的后堆栈设置图标:

Set the icon according to your fragment's backstack:

protected void setNavIcon() {
    int backStackEntryCount = getFragmentManager().getBackStackEntryCount();
    drawerToggle.setDrawerIndicatorEnabled(backStackEntryCount == 0);
}

按下抽屉图标时检测:

public boolean onOptionsItemSelected(MenuItem item) {
    if (drawerToggle.isDrawerIndicatorEnabled() && drawerToggle.onOptionsItemSelected(item)) {
        return true;
    }

    switch (item.getItemId()) {
      case x:
         return true;
      default:
         return false;
    }
}

并按下向上按钮:

public boolean onSupportNavigateUp() {
    onBackPressed();
    return true;
}

这对我有用.祝你好运.

This works for me. Good luck.

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