本节引言
前面我们已经跟大家讲解了实现底部导航栏的两种方案,但是这两种方案只适合普通的情况,如果 是像新浪微博那样的,想在底部导航栏上的item带有一个红色的小点,然后加上一个消息数目这样, 前面两种方案就显得无力了,我们来看看别人的APP是怎么做的,打开手机的开发者选项,勾选里面的: 显示布局边界,然后打开我们参考的那个App,可以看到底部导航栏是这样的:
从上面这个图我们就可以看出,这种底部导航栏不是简单的TextView或者RadioGroup构成的, 大概布局方案可能是:外层一个LinearLayout,中间一个RelativeLayout,而在中间有一个TextView, 然后再在TextView的右上角有一个红色圆圈背景的TextView或者一个红色的小点; 大概就这样,而这些小点平时的时候应该设置的不可见,当收到信息推送,即有相关类别信息的 时候再可见,并且显示对应的信息数目!那么下面我们就来实现下这种底部导航栏的效果, 另外,为了方便演示,这里就不演示Fragment的切换效果了!另外顺道复习下Fragment获得Activity 中的组件的知识点!
1.实现效果图:
为了方便理解,这里通过点击按钮的形式,模拟收到推送信息,然后显示红色点!
运行效果图:
2.实现流程:
好的,接下来我们就来实现上面这个效果~
Step 1:相关资源文件的准备:
和前面一样,准备好drawable系列的资源:
文字资源:tab_menu_text.xml
<?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:color="@color/text_yellow" android:state_selected="true" /> <item android:color="@color/text_gray" /> </selector>
图标资源:tab_menu_better.xml
<?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:drawable="@mipmap/tab_better_pressed" android:state_selected="true" /> <item android:drawable="@mipmap/tab_better_normal" /> </selector>
照着把其他三个也撸出来~!
Step 2:编写activity的布局代码:
因为四个选项的TextView以及右上角的红点数字属性都差不多,如下:
<TextView android:id="@+id/tab_menu_channel" android:layout_marginTop="5dp" android:layout_width="wrap_content" android:layout_height="48dp" android:layout_centerInParent="true" android:textColor="@drawable/tab_menu_text" android:drawableTop="@drawable/tab_menu_channel" android:text="@string/tab_menu_alert"/> <TextView android:layout_width="20dp" android:layout_height="20dp" android:background="@mipmap/bg_num" android:layout_toRightOf="@+id/tab_menu_channel" android:layout_marginLeft="-10dp" android:text="99+" android:textSize="12sp" android:gravity="center" android:textColor="@color/text_white"/>
我们将他们抽取出来,写到style.xml里:
<style name="tab_menu_text"> <item name="android:layout_marginTop">5dp</item> <item name="android:layout_width">wrap_content</item> <item name="android:layout_height">48dp</item> <item name="android:layout_centerInParent">true</item> <item name="android:textColor">@drawable/tab_menu_text</item> </style> <style name="tab_menu_bgnum"> <item name="android:layout_width">20dp</item> <item name="android:layout_height">20dp</item> <item name="android:background">@mipmap/bg_num</item> <item name="android:layout_marginLeft">-10dp</item> <item name="android:textSize">12sp</item> <item name="android:gravity">center</item> <item name="android:textColor">@color/text_white</item> </style>
然后开始编写我们的activity.xml布局:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <RelativeLayout android:id="@+id/ly_top_bar" android:layout_width="match_parent" android:layout_height="48dp" android:background="@color/bg_topbar"> <TextView android:id="@+id/txt_topbar" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_centerInParent="true" android:gravity="center" android:text="信息" android:textColor="@color/text_topbar" android:textSize="18sp" /> <View android:layout_width="match_parent" android:layout_height="2px" android:layout_alignParentBottom="true" android:background="@color/div_white" /> </RelativeLayout> <LinearLayout android:id="@+id/ly_tab_menu" android:layout_width="match_parent" android:layout_height="56dp" android:layout_alignParentBottom="true" android:background="@color/bg_white" android:orientation="horizontal"> <LinearLayout android:id="@+id/ly_tab_menu_channel" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center"> <RelativeLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:padding="5dp"> <TextView android:id="@+id/tab_menu_channel" style="@style/tab_menu_text" android:drawableTop="@drawable/tab_menu_channel" android:text="@string/tab_menu_alert" /> <TextView android:id="@+id/tab_menu_channel_num" style="@style/tab_menu_bgnum" android:layout_toRightOf="@+id/tab_menu_channel" android:text="99+" android:visibility="gone" /> </RelativeLayout> </LinearLayout> <LinearLayout android:id="@+id/ly_tab_menu_message" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center"> <RelativeLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:padding="5dp"> <TextView android:id="@+id/tab_menu_message" style="@style/tab_menu_text" android:drawableTop="@drawable/tab_menu_message" android:text="@string/tab_menu_profile" /> <TextView android:id="@+id/tab_menu_message_num" style="@style/tab_menu_bgnum" android:layout_toRightOf="@+id/tab_menu_message" android:text="99+" android:visibility="gone" /> </RelativeLayout> </LinearLayout> <LinearLayout android:id="@+id/ly_tab_menu_better" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center"> <RelativeLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:padding="5dp"> <TextView android:id="@+id/tab_menu_better" style="@style/tab_menu_text" android:drawableTop="@drawable/tab_menu_better" android:text="@string/tab_menu_pay" /> <TextView android:id="@+id/tab_menu_better_num" style="@style/tab_menu_bgnum" android:layout_toRightOf="@+id/tab_menu_better" android:text="99+" android:visibility="gone" /> </RelativeLayout> </LinearLayout> <LinearLayout android:id="@+id/ly_tab_menu_setting" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center"> <RelativeLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:padding="5dp"> <TextView android:id="@+id/tab_menu_setting" style="@style/tab_menu_text" android:drawableTop="@drawable/tab_menu_setting" android:text="@string/tab_menu_alert" /> <ImageView android:id="@+id/tab_menu_setting_partner" android:layout_width="12dp" android:layout_height="12dp" android:layout_marginLeft="-5dp" android:layout_toRightOf="@id/tab_menu_setting" android:visibility="gone" android:src="@mipmap/partner_red" /> </RelativeLayout> </LinearLayout> </LinearLayout> <View android:id="@+id/div_tab_bar" android:layout_width="match_parent" android:layout_height="2px" android:layout_above="@id/ly_tab_menu" android:background="@color/div_white" /> <FrameLayout android:id="@+id/ly_content" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_above="@id/div_tab_bar" android:layout_below="@id/ly_top_bar"/> </RelativeLayout>
Step 3:编写Fragment界面布局以及类
Fragment布局由四个普通按钮构成:
fg_my.xml:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:padding="5dp"> <Button android:id="@+id/btn_one" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="第一个显示信息"/> <Button android:id="@+id/btn_two" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="第二个显示信息"/> <Button android:id="@+id/btn_three" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="第三个显示信息"/> <Button android:id="@+id/btn_four" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="第四个显示信息"/> </LinearLayout>
接着是自定义的Fragment类,这里的话我们通过getActivity.findViewById()来获得Activity 中的小红点,这里仅仅是简单的控制显示而已! MyFragment.java:
public class MyFragment extends Fragment implements View.OnClickListener{ private Context mContext; private Button btn_one; private Button btn_two; private Button btn_three; private Button btn_four; public MyFragment() { } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fg_my,container,false); //UI Object btn_one = (Button) view.findViewById(R.id.btn_one); btn_two = (Button) view.findViewById(R.id.btn_two); btn_three = (Button) view.findViewById(R.id.btn_three); btn_four = (Button) view.findViewById(R.id.btn_four); //Bind Event btn_one.setOnClickListener(this); btn_two.setOnClickListener(this); btn_three.setOnClickListener(this); btn_four.setOnClickListener(this); return view; } @Override public void onClick(View v) { switch (v.getId()){ case R.id.btn_one: TextView tab_menu_channel_num = (TextView) getActivity ().findViewById(R.id.tab_menu_channel_num); tab_menu_channel_num.setText("11"); tab_menu_channel_num.setVisibility(View.VISIBLE); break; case R.id.btn_two: TextView tab_menu_message_num = (TextView) getActivity ().findViewById(R.id.tab_menu_message_num); tab_menu_message_num.setText("20"); tab_menu_message_num.setVisibility(View.VISIBLE); break; case R.id.btn_three: TextView tab_menu_better_num = (TextView) getActivity ().findViewById(R.id.tab_menu_better_num); tab_menu_better_num.setText("99+"); tab_menu_better_num.setVisibility(View.VISIBLE); break; case R.id.btn_four: ImageView tab_menu_setting_partner = (ImageView) getActivity ().findViewById(R.id.tab_menu_setting_partner); tab_menu_setting_partner.setVisibility(View.VISIBLE); break; } } }
Step 4:编写MainActivity
我们在这里完成主要的逻辑实现,有些部分和前面TextView实现底部导航栏的效果类似, 就不具体讲解了,代码如下:
MainActivity.java:
/** * Created by Coder-pig on 2015/8/30 0030. */ public class MainActivity extends AppCompatActivity implements View.OnClickListener { //Activity UI Object private LinearLayout ly_tab_menu_channel; private TextView tab_menu_channel; private TextView tab_menu_channel_num; private LinearLayout ly_tab_menu_message; private TextView tab_menu_message; private TextView tab_menu_message_num; private LinearLayout ly_tab_menu_better; private TextView tab_menu_better; private TextView tab_menu_better_num; private LinearLayout ly_tab_menu_setting; private TextView tab_menu_setting; private ImageView tab_menu_setting_partner; private FragmentManager fManager; private FragmentTransaction fTransaction; private MyFragment fg1; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); bindViews(); ly_tab_menu_channel.performClick(); fg1 = new MyFragment(); fManager = getFragmentManager(); fTransaction = fManager.beginTransaction(); fTransaction.add(R.id.ly_content, fg1).commit(); } private void bindViews() { ly_tab_menu_channel = (LinearLayout) findViewById(R.id.ly_tab_menu_channel); tab_menu_channel = (TextView) findViewById(R.id.tab_menu_channel); tab_menu_channel_num = (TextView) findViewById(R.id.tab_menu_channel_num); ly_tab_menu_message = (LinearLayout) findViewById(R.id.ly_tab_menu_message); tab_menu_message = (TextView) findViewById(R.id.tab_menu_message); tab_menu_message_num = (TextView) findViewById(R.id.tab_menu_message_num); ly_tab_menu_better = (LinearLayout) findViewById(R.id.ly_tab_menu_better); tab_menu_better = (TextView) findViewById(R.id.tab_menu_better); tab_menu_better_num = (TextView) findViewById(R.id.tab_menu_better_num); ly_tab_menu_setting = (LinearLayout) findViewById(R.id.ly_tab_menu_setting); tab_menu_setting = (TextView) findViewById(R.id.tab_menu_setting); tab_menu_setting_partner = (ImageView) findViewById(R.id.tab_menu_setting_partner); ly_tab_menu_channel.setOnClickListener(this); ly_tab_menu_message.setOnClickListener(this); ly_tab_menu_better.setOnClickListener(this); ly_tab_menu_setting.setOnClickListener(this); } @Override public void onClick(View v) { switch (v.getId()) { case R.id.ly_tab_menu_channel: setSelected(); tab_menu_channel.setSelected(true); tab_menu_channel_num.setVisibility(View.INVISIBLE); break; case R.id.ly_tab_menu_message: setSelected(); tab_menu_message.setSelected(true); tab_menu_message_num.setVisibility(View.INVISIBLE); break; case R.id.ly_tab_menu_better: setSelected(); tab_menu_better.setSelected(true); tab_menu_better_num.setVisibility(View.INVISIBLE); break; case R.id.ly_tab_menu_setting: setSelected(); tab_menu_setting.setSelected(true); tab_menu_setting_partner.setVisibility(View.INVISIBLE); break; } } //重置所有文本的选中状态 private void setSelected() { tab_menu_channel.setSelected(false); tab_menu_message.setSelected(false); tab_menu_better.setSelected(false); tab_menu_setting.setSelected(false); } }
好的,至此,就大功告成了~
3.代码下载:
FragmentDemo3.zip:FragmentDemo3.zip下载
4.本节小结:
好的,本节相比前面两节稍微复杂了一点,不过还是比较容易弄懂的! 另外,关于实现普通底部导航栏的实现例子就写这么多吧,下一节开始我们来写下 在此基础上的根据手势操作切换页面的例子,嗯,就说这么多,谢谢~
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