ViewPager + Fragment 實現類微信界面

時間 2019-11-14

標籤 viewpager fragment 實現微信界面欄目 Android 简体版

原文原文鏈接

　　在現在的互聯網時代，微信已經是一個超級App。這篇經過ViewPager + Fragment實現一個相似於微信的界面，以前有用FragmentTabHost實現過相似界面，ViewPager的實現方式相對於FragmentTabHost的方式更簡單明瞭。java

ViewPager:android

　　ViewPager繼承自ViewGroup,是一個容器類，能夠往裏添加View.
微信

　　ViewPager的使用很簡單，經過setAdapter()方法設置一個PagerAdapter便可，這個PagerAdapter須要本身寫，實現裏面的一些方法。本篇要和Fragment結合，因此實現的是FragmentPagerAdapter類，FragmentPagerAdapter繼承自PagerAdapter.app

　　ViewPager經過addOnPageChangeListener（）方法能夠設置一個ViewPager.OnPageChangeListener監聽，當Pager發生變化時就調用相應的方法。ide

Fragment:佈局

　　Fragment有本身的生命週期，有興趣的能夠本身經過各類方式研究下（本身打Log看是最簡單的一種方式），這裏就不在贅述。和ViewPager結合，有幾個Pager就須要實現幾個不一樣的Fragment.this

先看一下最後實現的效果圖：spa

佈局上分爲三部分：3d

　　最上面的layout_top.xml,主要就是上面那個標題，就一個TextView，中間的ViewPager,最下面的layout_bottom.xml包括三個線性佈局，每一個線性佈局包括一個ImageView和TextView.code

activity_main.xml:

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     xmlns:tools="http://schemas.android.com/tools"
 4     android:layout_width="match_parent"
 5     android:layout_height="match_parent"
 6     android:orientation="vertical"
 7     tools:context="com.example.administrator.viewpagerl.MainActivity">
 8 
 9     <include layout="@layout/layout_top"></include>
10     
11     <android.support.v4.view.ViewPager
12         android:id="@+id/ViewPagerLayout"
13         android:layout_width="match_parent"
14         android:layout_height="match_parent"
15         android:layout_weight="1">
16     </android.support.v4.view.ViewPager>
17 
18     <include layout="@layout/layout_bottom"></include>
19 
20 </LinearLayout>

layout_top.xml

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:orientation="horizontal"
 4     android:layout_width="match_parent"
 5     android:layout_height="wrap_content"
 6     android:paddingTop="3dp"
 7     android:paddingBottom="3dp"
 8     android:background="@android:color/darker_gray">
 9 
10     <TextView
11         android:id="@+id/ViewTitle"
12         android:layout_marginLeft="20dp"
13         android:layout_marginTop="5dp"
14         android:textSize="25sp"
15         android:layout_width="wrap_content"
16         android:layout_height="wrap_content" />
17 
18 </LinearLayout>

View Code

layout_bottom.xml

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:orientation="horizontal" android:layout_width="match_parent"
 4     android:layout_height="wrap_content"
 5     android:layout_alignParentBottom="true"
 6     android:paddingTop="3dp"
 7     android:paddingBottom="3dp"
 8     android:background="@android:color/holo_green_light">
 9 
10     <LinearLayout
11         android:id="@+id/firstLinearLayout"
12         android:layout_width="wrap_content"
13         android:layout_height="wrap_content"
14         android:orientation="vertical"
15         android:gravity="center_horizontal"
16         android:layout_weight="1">
17         <ImageView
18             android:id="@+id/firstImageView"
19             android:background="@drawable/tab_weixin"
20             android:layout_width="wrap_content"
21             android:layout_height="wrap_content" />
22         <TextView
23             android:id="@+id/firstTextView"
24             android:layout_width="wrap_content"
25             android:layout_height="wrap_content"
26             android:text="微信"
27             />
28     </LinearLayout>
29     <LinearLayout
30         android:id="@+id/secondLinearLayout"
31         android:layout_width="wrap_content"
32         android:layout_height="wrap_content"
33         android:orientation="vertical"
34         android:gravity="center_horizontal"
35         android:layout_weight="1">
36         <ImageView
37             android:id="@+id/secondImageView"
38             android:layout_width="wrap_content"
39             android:layout_height="wrap_content"
40             android:background="@drawable/tab_setting"/>
41         <TextView
42             android:id="@+id/secondTextView"
43             android:layout_width="wrap_content"
44             android:layout_height="wrap_content"
45             android:text="朋友"
46             />
47     </LinearLayout>
48     <LinearLayout
49         android:id="@+id/threeLinearLayout"
50         android:layout_width="wrap_content"
51         android:layout_height="wrap_content"
52         android:orientation="vertical"
53         android:gravity="center_horizontal"
54         android:layout_weight="1">
55         <ImageView
56             android:id="@+id/threeImageView"
57             android:layout_width="wrap_content"
58             android:layout_height="wrap_content"
59             android:background="@drawable/tab_find"/>
60         <TextView
61             android:id="@+id/threeTextView"
62             android:layout_width="wrap_content"
63             android:layout_height="wrap_content"
64             android:text="發現"
65             />
66     </LinearLayout>
67 </LinearLayout>

View Code

　　上面有提到，ViewPager須要實現一個Pageradapter，很簡單繼承FragmentPagerAdapter,實現裏面的getItem()和getCount()方法便可。

ViewPagerFragmentAdapter .java

 1 package com.example.administrator.viewpagerl;
 2 
 3 import android.support.v4.app.Fragment;
 4 import android.support.v4.app.FragmentManager;
 5 import android.support.v4.app.FragmentPagerAdapter;
 6 import android.util.Log;
 7 
 8 import java.util.ArrayList;
 9 import java.util.List;
10 
11 public class ViewPagerFragmentAdapter extends FragmentPagerAdapter {
12 
13     private List<Fragment> mList = new ArrayList<Fragment>();
14     public ViewPagerFragmentAdapter(FragmentManager fm , List<Fragment> list) {
15         super(fm);
16         this.mList = list;
17     }
18 
19     @Override
20     public Fragment getItem(int position) {
21         return mList.get(position);
22     }
23 
24     @Override
25     public int getCount() {
26         return mList != null ? mList.size() : 0;
27     }
28 }

　　ViewPager的每一個Pager都須要一個Fragment,Fragment會實例化佈局，顯示在ViewPager的每一個Pager中

ChatFragment.java

 1 package com.example.administrator.fragment;
 2 
 3 import android.os.Bundle;
 4 import android.support.annotation.Nullable;
 5 import android.support.v4.app.Fragment;
 6 import android.util.Log;
 7 import android.view.LayoutInflater;
 8 import android.view.View;
 9 import android.view.ViewGroup;
10 import android.widget.TextView;
11 
12 import com.example.administrator.viewpagerl.R;
13 
14 public class ChatFragment extends Fragment {
15 
16     View mView;
17     @Nullable
18     @Override
19     public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
20         if (mView == null) {
21             mView = inflater.inflate(R.layout.fragment_layout,null);
22         }
23         ((TextView)mView.findViewById(R.id.mTextView)).setText("聊天界面");
24         return mView;
25     }
26 }

　　這裏須要三個Fragment,由於這裏使用的佈局很簡單，三個佈局基本是一致的，FriendFragment、FindFragment 這裏就都不貼出代碼了。微信裏面的聊天列表，朋友列表都是在Fragment裏面實例化的佈局裏有個ListView,經過ListView的方式實現的，這裏只是爲了記錄ViewPager就沒有實現那些，有興趣的能夠本身搞搞，其實也不難。

　　在Activity裏面只須要給ViewPager設置上面那個Adapter,設置一個監聽知道Pager如何變化便可。點擊最下面微信、朋友、發現三個按鈕，經過ViewPager的setCurrentItem()方法就能跳轉到對應的Pager，除了這些還有就是經過一些簡單的邏輯，控制一下界面的改變就行，沒有太難的東西。

MainActivity.java

  1 package com.example.administrator.viewpagerl;
  2 
  3 import android.support.v4.app.Fragment;
  4 import android.support.v4.app.FragmentManager;
  5 import android.support.v4.view.ViewPager;
  6 import android.support.v7.app.AppCompatActivity;
  7 import android.os.Bundle;
  8 import android.util.Log;
  9 import android.view.View;
 10 import android.widget.LinearLayout;
 11 import android.widget.TextView;
 12 
 13 import com.example.administrator.fragment.ChatFragment;
 14 import com.example.administrator.fragment.FindFragment;
 15 import com.example.administrator.fragment.FriendFragment;
 16 
 17 import java.util.ArrayList;
 18 import java.util.List;
 19 
 20 public class MainActivity extends AppCompatActivity implements View.OnClickListener {
 21 
 22     private static final String TAG = "MainActivity.TAG";
 23     TextView titleTextView;
 24     public LinearLayout firstLinearLayout;
 25     public LinearLayout secondLinearLayout;
 26     public LinearLayout threeLinearLayout;
 27     ViewPager mViewPager;
 28     ViewPagerFragmentAdapter mViewPagerFragmentAdapter;
 29     FragmentManager mFragmentManager;
 30 
 31     String[] titleName = new String[] {"微信","朋友","發現"};
 32     List<Fragment> mFragmentList = new ArrayList<Fragment>();
 33     @Override
 34     protected void onCreate(Bundle savedInstanceState) {
 35         super.onCreate(savedInstanceState);
 36         mFragmentManager = getSupportFragmentManager();
 37         setContentView(R.layout.activity_main);
 38         initFragmetList();
 39         mViewPagerFragmentAdapter = new ViewPagerFragmentAdapter(mFragmentManager,mFragmentList);
 40         initView();
 41         initViewPager();
 42     }
 43 
 44     @Override
 45     protected void onResume() {
 46         super.onResume();
 47     }
 48 
 49     public void initViewPager() {
 50         mViewPager.addOnPageChangeListener(new ViewPagetOnPagerChangedLisenter());
 51         mViewPager.setAdapter(mViewPagerFragmentAdapter);
 52         mViewPager.setCurrentItem(0);
 53         titleTextView.setText(titleName[0]);
 54         updateBottomLinearLayoutSelect(true,false,false);
 55     }
 56 
 57     public void initFragmetList() {
 58         Fragment chat = new ChatFragment();
 59         Fragment friend = new FriendFragment();
 60         Fragment find = new FindFragment();
 61         mFragmentList.add(chat);
 62         mFragmentList.add(friend);
 63         mFragmentList.add(find);
 64     }
 65 
 66     public void initView() {
 67         titleTextView = (TextView) findViewById(R.id.ViewTitle);
 68         mViewPager = (ViewPager) findViewById(R.id.ViewPagerLayout);
 69         firstLinearLayout = (LinearLayout) findViewById(R.id.firstLinearLayout);
 70         firstLinearLayout.setOnClickListener(this);
 71         secondLinearLayout = (LinearLayout) findViewById(R.id.secondLinearLayout);
 72         secondLinearLayout.setOnClickListener(this);
 73         threeLinearLayout = (LinearLayout) findViewById(R.id.threeLinearLayout);
 74         threeLinearLayout.setOnClickListener(this);
 75     }
 76 
 77     @Override
 78     public void onClick(View v) {
 79         switch (v.getId()) {
 80             case R.id.firstLinearLayout:
 81                 mViewPager.setCurrentItem(0);
 82                 updateBottomLinearLayoutSelect(true,false,false);
 83                 break;
 84             case R.id.secondLinearLayout:
 85                 mViewPager.setCurrentItem(1);
 86                 updateBottomLinearLayoutSelect(false,true,false);
 87                 break;
 88             case R.id.threeLinearLayout:
 89                 mViewPager.setCurrentItem(2);
 90                 updateBottomLinearLayoutSelect(false,false,true);
 91                 break;
 92             default:
 93                 break;
 94         }
 95     }
 96     private void updateBottomLinearLayoutSelect(boolean f, boolean s, boolean t) {
 97         firstLinearLayout.setSelected(f);
 98         secondLinearLayout.setSelected(s);
 99         threeLinearLayout.setSelected(t);
100     }
101     class ViewPagetOnPagerChangedLisenter implements ViewPager.OnPageChangeListener {
102         @Override
103         public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
104 //            Log.d(TAG,"onPageScrooled");
105         }
106         @Override
107         public void onPageSelected(int position) {
108             Log.d(TAG,"onPageSelected");
109             boolean[] state = new boolean[titleName.length];
110             state[position] = true;
111             titleTextView.setText(titleName[position]);
112             updateBottomLinearLayoutSelect(state[0],state[1],state[2]);
113         }
114         @Override
115         public void onPageScrollStateChanged(int state) {
116             Log.d(TAG,"onPageScrollStateChanged");
117         }
118     }
119 }