Fragment Examples - Implementation of the Bottom Navigation Bar (Method 3)
Introduction to this section
We have already explained to you two options for implementing the bottom navigation bar, but these two options are only suitable for ordinary situations. If Like Sina Weibo, I want to put a red dot on the item on the bottom navigation bar, and then add a message number like this, The first two options are useless. Let’s take a look at how other people’s apps do it. Open the developer options on your phone, check the box: Display layout boundaries, and then open the app we’re referring to. , you can see that the bottom navigation bar looks like this:
From the above picture, we can see that this bottom navigation bar is not composed of a simple TextView or RadioGroup. The approximate layout plan may be: a LinearLayout in the outer layer, a RelativeLayout in the middle, and a TextView in the middle. Then there is a TextView with a red circle background or a small red dot in the upper right corner of the TextView; That's about it, and these little dots should be set to invisible in normal times. When you receive push information, there will be relevant category information. It will be visible again when the time comes, and the corresponding information number will be displayed! So let’s realize the effect of this bottom navigation bar. In addition, for the convenience of demonstration, the switching effect of Fragment will not be demonstrated here! In addition, review Fragment to obtain Activity Knowledge points about the components in !
1. Implementation renderings:
In order to facilitate understanding, here we simulate receiving push information by clicking a button, and then display a red dot!
Running renderings:
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>Icon resource:
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>Follow the example and pull out the other three~!
Step 2: Write the layout code of the activity: Because the TextView of the four options and the red dot digital properties in the upper right corner are similar, as follows:
<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="../style/images/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"/>We extract them and write them into style.xml:
<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>Then start writing our activity.xml layout:
<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="../style/images/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="../style/images/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="../style/images/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="../style/images/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: Write Fragment interface layout and classFragment layout consists of four ordinary buttons:
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>Then there is the custom Fragment class, here we pass getActivity .findViewById() to get Activity The little red dot in is just a simple control display!
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: Write MainActivityWe complete the main logic implementation here, some parts are the same as the previous TextView implementation of the bottom navigation bar The effect is similar, I won’t explain it in detail. The code is as follows:
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);
}
}Okay, now you’re done~
3. Code download:
FragmentDemo3.zip：FragmentDemo3.zip download
4. Summary of this section:
Okay, compared to this section The first two sections are a little more complicated, but still relatively easy to understand! In addition, there are only so many implementation examples for implementing a common bottom navigation bar. Let’s start with the next section. Based on this, examples of switching pages based on gesture operations, well, that’s all, thank you~
