JamesMusic浅读--------3，欢迎界面。

来源：互联网发布：java缓存过程面试编辑：程序博客网时间：2024/06/08 15:13

我们通过读代码发现，数据库写操作是在欢迎界面里面设置的，那么我们先实现欢迎界面。

为了更好的复制代码，我们先实现一些简单的Helper类。

首先是设置字体的，这个很简单。

//Caches the custom fonts in memory to improve rendering performance.public class TypefaceHelper {public static final String TYPEFACE_FOLDER = "fonts";public static final String TYPEFACE_EXTENSION = ".ttf";private static Hashtable<String, Typeface> sTypeFaces = new Hashtable<String, Typeface>(4);public static Typeface getTypeface(Context context, String fileName) {Typeface tempTypeface = sTypeFaces.get(fileName);if (tempTypeface==null) {    String fontPath = new StringBuilder(TYPEFACE_FOLDER).append('/')    .append(fileName)    .append(TYPEFACE_EXTENSION)    .toString();        tempTypeface = Typeface.createFromAsset(context.getAssets(), fontPath);    sTypeFaces.put(fileName, tempTypeface);}return tempTypeface;}}

现在开始实现WelcomActivity类。由于欢迎界面是用Fragment呈现的，我们用Fragment来管理。

public class WelcomeActivity extends AppCompatActivity {    private Context mContext;    private Common mApp;    private ViewPager welcomeViewPager;  //  private LinePageIndicator indicator;    private String mAccountName;  //  private MusicFoldersFragment mMusicFoldersFragment;//    public static BuildingLibraryProgressFragment mBuildingLibraryProgressFragment;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        mContext = this;        mApp = (Common) this.getApplicationContext();        overridePendingTransition(R.anim.fade_in, R.anim.fade_out);        setContentView(R.layout.activity_welcome);        setTheme(R.style.AppTheme);        if (getActionBar()!=null)            getActionBar().hide();        welcomeViewPager = (ViewPager) findViewById(R.id.welcome_pager);        FragmentManager fm = getSupportFragmentManager();        welcomeViewPager.setAdapter(new WelcomePagerAdapter(fm));        welcomeViewPager.setOffscreenPageLimit(6);    }    class  WelcomePagerAdapter extends FragmentStatePagerAdapter{        public WelcomePagerAdapter(FragmentManager fm) {            super(fm);        }        @Override        public Fragment getItem(int position) {            return  new WelcomeFragment();        }        @Override        public int getCount() {            return 1;        }    }}

第一个界面搞定了。

下面在添加一个Fragment

/** * Created by kankan on 2016/5/26. */public class MusicFoldersFragment extends Fragment {    @Nullable    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {        View view = inflater.inflate(R.layout.fragment_welcome_screen_2, container, false);        return view;    }}

在修改一下Adapter。这样结果如图

下面就是添加目录选择的功能了。

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