android开发之viewpager and Fragment
Android ViewPager和Fragment实现顶部导航界面滑动效果
Layout 管理器允许用户可以在页面上，左右滑动来翻动页面。你可以考虑实现PagerAdapter接口来显示
该效果。ViewPager很多时候会结合Fragment一块使用，这种方法使得管理每个页面的生命周期变得很方便。
些adapter的具体实现，可以适合于这种ViewPager结合Fragment使用的情况。这些adapter包括：
其中，有一FragmentPagerAdapter,和 FragmentStatePagerAdapter。
而本文就是通过ViewPager结合Fragment利用FragmentpagerAdapter适配器来实现左右滑动的效果。
1·代码：
activity_main.xml
<span style="font-family:Microsoft YaHei;font-size:18px;"><LinearLayout 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" android:orientation="vertical" > <include layout="@layout/activity_main_top_tab" /> <android.support.v4.view.ViewPager android:id="@+id/id_page_vp" android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" > </android.support.v4.view.ViewPager> </LinearLayout></span>
activity_main_top_tab.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical" > <LinearLayout android:id="@+id/id_switch_tab_ll" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:baselineAligned="false" > <LinearLayout android:id="@+id/id_tab_chat_ll" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_weight="1" android:background="@drawable/guide_round_selector" android:gravity="center" android:orientation="horizontal" android:padding="10dip" > <TextView android:id="@+id/id_chat_tv" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center" android:text="聊天" android:textColor="#0000FF" android:textSize="15dip" /> </LinearLayout> <LinearLayout android:id="@+id/id_tab_friend_ll" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_weight="1" android:background="@drawable/guide_round_selector" android:clickable="true" android:gravity="center" android:orientation="horizontal" android:padding="10dip" android:saveEnabled="false" > <TextView android:id="@+id/id_friend_tv" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center" android:text="好友" android:textColor="#000000" android:textSize="15dip" /> </LinearLayout> <LinearLayout android:id="@+id/id_tab_contacts_ll" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_weight="1" android:background="@drawable/guide_round_selector" android:focusable="false" android:gravity="center" android:orientation="horizontal" android:padding="10dip" > <TextView android:id="@+id/id_contacts_tv" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center" android:text="通讯录" android:textColor="#000000" android:textSize="15dip" /> </LinearLayout> </LinearLayout> <ImageView android:id="@+id/id_tab_line_iv" android:layout_width="200dp" android:layout_height="wrap_content" android:contentDescription="tab" android:background="@drawable/tab_selected_pressed_holo" > </ImageView> <View android:layout_width="match_parent" android:layout_height="1dp" android:background="#000000" /> </LinearLayout>
Fragment显示布局layout1
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@color/colorPrimary" android:weightSum="1"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:weightSum="1" android:id="@+id/linearLayout" android:layout_alignParentTop="true" android:layout_alignBottom="@+id/editText"> <TextView android:id="@+id/atext" android:text="上午" android:gravity="center" android:layout_width="54dp" android:layout_height="wrap_content" android:theme="@style/AlertDialog.AppCompat" android:textSize="20dp" /> <TextView android:id="@+id/text1" android:text="8" android:gravity="center" android:layout_width="44dp" android:layout_height="wrap_content" android:theme="@style/AlertDialog.AppCompat" android:textSize="50dp" /> <TextView android:text=":" android:gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content" android:theme="@style/AlertDialog.AppCompat" android:textSize="50dp" /> <TextView android:id="@+id/text00" android:text="00" android:gravity="center" android:layout_width="70dp" android:layout_height="wrap_content" android:theme="@style/AlertDialog.AppCompat" android:textSize="50dp" /> <Switch android:id="@+id/aswitch" android:gravity="center" android:layout_width="match_parent" android:layout_height="match_parent" /> </LinearLayout> <EditText android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/editText" android:layout_alignParentStart="true" android:layout_alignParentEnd="true" android:layout_above="@+id/btn" android:layout_marginBottom="319dp" android:layout_alignParentTop="true" android:layout_marginTop="176dp" /> <android.support.design.widget.FloatingActionButton android:id="@+id/btn" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="bottom|end" android:src="@android:drawable/ic_dialog_email" android:layout_marginLeft="@dimen/fab_margin" android:layout_marginRight="@dimen/fab_margin" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:layout_marginBottom="14dp" /> </RelativeLayout >
主函数MainActivity.java
package asfas.myclock; import android.graphics.Color; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentActivity; import android.support.v4.view.ViewPager; import android.text.Layout; import android.util.DisplayMetrics; import android.util.Log; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.TextView; import java.util.ArrayList; import java.util.List; public class MainActivity extends FragmentActivity { private List<Fragment> mFragmentList = new ArrayList<Fragment>(); private FragmentAdapter mFragmentAdapter; private ViewPager mPageVp; /** * Tab显示内容TextView */ private TextView mTabChatTv, mTabContactsTv, mTabFriendTv; /** * Tab的那个引导线 */ private ImageView mTabLineIv; /** * Fragment */ private Layout /** * ViewPager的当前选中页 */ private int currentIndex; /** * 屏幕的宽度 */ private int screenWidth; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); findById(); init(); initTabLineWidth(); } private void findById() { mTabContactsTv = (TextView) this.findViewById(R.id.id_contacts_tv); mTabChatTv = (TextView) this.findViewById(R.id.id_chat_tv); mTabFriendTv = (TextView) this.findViewById(R.id.id_friend_tv); mTabLineIv = (ImageView) this.findViewById(R.id.id_tab_line_iv); mPageVp = (ViewPager) this.findViewById(R.id.id_page_vp); } private void init() { mFriendFg = new FriendFragment(); mContactsFg = new ContactsFragment(); mChatFg = new ChatFragment(); mFragmentList.add(mChatFg); mFragmentList.add(mFriendFg); mFragmentList.add(mContactsFg); mFragmentAdapter = new FragmentAdapter( this.getSupportFragmentManager(), mFragmentList); mPageVp.setAdapter(mFragmentAdapter); mPageVp.setCurrentItem(0); mPageVp.setOnPageChangeListener(new ViewPager.OnPageChangeListener() { /** * state滑动中的状态 有三种状态（0，1，2） 1：正在滑动 2：滑动完毕 0：什么都没做。 */ @Override public void onPageScrollStateChanged(int state) { } /** * position :当前页面，及你点击滑动的页面 offset:当前页面偏移的百分比 * offsetPixels:当前页面偏移的像素位置 */ @Override public void onPageScrolled(int position, float offset, int offsetPixels) { LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) mTabLineIv .getLayoutParams(); Log.e("offset:", offset + ""); /** * 利用currentIndex(当前所在页面)和position(下一个页面)以及offset来 * 设置mTabLineIv的左边距 滑动场景： * 记3个页面, * 从左到右分别为0,1,2 * 0->1; 1->2; 2->1; 1->0 */ if (currentIndex == 0 && position == 0)// 0->1 { lp.leftMargin = (int) (offset * (screenWidth * 1.0 / 3) + currentIndex * (screenWidth / 3)); } else if (currentIndex == 1 && position == 0) // 1->0 { lp.leftMargin = (int) (-(1 - offset) * (screenWidth * 1.0 / 3) + currentIndex * (screenWidth / 3)); } else if (currentIndex == 1 && position == 1) // 1->2 { lp.leftMargin = (int) (offset * (screenWidth * 1.0 / 3) + currentIndex * (screenWidth / 3)); } else if (currentIndex == 2 && position == 1) // 2->1 { lp.leftMargin = (int) (-(1 - offset) * (screenWidth * 1.0 / 3) + currentIndex * (screenWidth / 3)); } mTabLineIv.setLayoutParams(lp); } @Override public void onPageSelected(int position) { resetTextView(); switch (position) { case 0: mTabChatTv.setTextColor(Color.BLUE); break; case 1: mTabFriendTv.setTextColor(Color.BLUE); break; case 2: mTabContactsTv.setTextColor(Color.BLUE); break; } currentIndex = position; } }); } /** * 设置滑动条的宽度为屏幕的1/3(根据Tab的个数而定) */ private void initTabLineWidth() { DisplayMetrics dpMetrics = new DisplayMetrics(); getWindow().getWindowManager().getDefaultDisplay() .getMetrics(dpMetrics); screenWidth = dpMetrics.widthPixels; LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) mTabLineIv .getLayoutParams(); lp.width = screenWidth / 3; mTabLineIv.setLayoutParams(lp); } /** * 重置颜色 */ private void resetTextView() { mTabChatTv.setTextColor(Color.BLACK); mTabFriendTv.setTextColor(Color.BLACK); mTabContactsTv.setTextColor(Color.BLACK); } }
Fragment适配器
import java.util.ArrayList; import java.util.List; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentPagerAdapter; public class FragmentAdapter extends FragmentPagerAdapter { List<Fragment> fragmentList = new ArrayList<Fragment>(); public FragmentAdapter(FragmentManager fm,List<Fragment> fragmentList) { super(fm); this.fragmentList = fragmentList; } @Override public Fragment getItem(int position) { return fragmentList.get(position); } @Override public int getCount() { return fragmentList.size(); } }
Fragment显示函数
import android.os.Bundle; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; public class ChatFragment extends Fragment { @Override public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState){ super.onCreateView(inflater, container, savedInstanceState); View chatView = inflater.inflate(R.layout.activity_tab_chat, container,false); return chatView; } @Override public void onActivityCreated(Bundle savedInstanceState){ super.onActivityCreated(savedInstanceState); } }
这是大概 明天修改。
