一般的app第一次安裝啟動的時候,都會有一個啟動頁面和引導頁的畫面,然后才進入主程序。anndroid中的ViewPagerAdapter 是一個繼承與PageAdapter的 頁面引導適配器。由於我的筆記本太卡,AndroidStudio hold不住,裝X不成功,狠心卸載了,買新電腦之前還是用eclipse頂着。最近也寫了個demo試了一下,覺得還可以。
1.新建一個項目,結構如圖:
初始頁面splash.xml
1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 2 xmlns:tools="http://schemas.android.com/tools" 3 android:layout_width="match_parent" 4 android:layout_height="match_parent" 5 tools:context=".SplashActivity" > 6 7 <ImageView 8 android:layout_width="match_parent" 9 android:layout_height="match_parent" 10 android:adjustViewBounds="true" 11 android:background="@drawable/welcome_android" 12 android:scaleType="centerCrop" /> 13 14 <TextView 15 android:id="@+id/txtTime" 16 android:layout_width="wrap_content" 17 android:layout_height="wrap_content" 18 android:layout_alignParentRight="true" 19 android:layout_alignParentTop="true" 20 android:layout_marginRight="20dp" 21 android:layout_marginTop="21dp" 22 android:textSize="18dp" 23 android:text="3秒" /> 24 25 </RelativeLayout>
SplashActivity.java后台代碼
1 package com.wym.dxdmallandroid; 2 3 import java.util.Timer; 4 import java.util.TimerTask; 5 6 import com.dxd.dxdmallandroid.R; 7 8 import android.app.Activity; 9 import android.content.Intent; 10 import android.content.SharedPreferences; 11 import android.os.Bundle; 12 import android.os.Handler; 13 import android.os.Message; 14 import android.view.View; 15 import android.widget.TextView; 16 17 /** 18 * Author:WYM 19 */ 20 public class SplashActivity extends Activity { 21 boolean isFirstIn = false; 22 23 private static final int GO_HOME = 1000; 24 private static final int GO_GUIDE = 1001; 25 private static final long SPLASH_DELAY_MILLIS = 3000;// 延遲3秒 26 private static final String SHAREDPREFERENCES_NAME = "first_pref";//存取程序是否是第一次啟動 27 private TextView txtTime; 28 private int recLen = 3; 29 Timer timer = new Timer(); 30 /** 31 * Handler:跳轉到不同界面 32 */ 33 private Handler mHandler = new Handler() { 34 35 @Override 36 public void handleMessage(Message msg) { 37 switch (msg.what) { 38 case GO_HOME: 39 goHome(); 40 break; 41 case GO_GUIDE: 42 goGuide(); 43 break; 44 } 45 super.handleMessage(msg); 46 } 47 }; 48 49 50 51 @Override 52 protected void onCreate(Bundle savedInstanceState) { 53 super.onCreate(savedInstanceState); 54 setContentView(R.layout.splash); 55 txtTime=(TextView) findViewById(R.id.txtTime); 56 TimerTask task = new TimerTask() { 57 @Override 58 public void run() { 59 runOnUiThread(new Runnable() { //ui thread 60 @Override 61 public void run() { 62 txtTime.setText(recLen+"秒"); 63 recLen--; 64 if(recLen<-1) 65 { 66 timer.cancel(); 67 txtTime.setVisibility(View.GONE); 68 } 69 } 70 }); 71 } 72 }; 73 timer.schedule(task, 1000, 1000); // timeTask 74 init(); 75 } 76 77 private void init() { 78 79 // 讀取SharedPreferences中需要的數據 80 // 使用SharedPreferences來記錄程序的使用次數 81 SharedPreferences preferences = getSharedPreferences( 82 SHAREDPREFERENCES_NAME, MODE_PRIVATE); 83 84 // 取得相應的值,如果沒有該值,說明還未寫入,用true作為默認值 85 isFirstIn = preferences.getBoolean("isFirstIn", true); 86 87 88 // 判斷程序與第幾次運行,如果是第一次運行則跳轉到引導界面,否則跳轉到主界面 89 if (!isFirstIn) { 90 // 使用Handler的postDelayed方法,3秒后執行跳轉到MainActivity 91 mHandler.sendEmptyMessageDelayed(GO_HOME, SPLASH_DELAY_MILLIS); 92 } else { 93 mHandler.sendEmptyMessageDelayed(GO_GUIDE, SPLASH_DELAY_MILLIS); 94 } 95 96 } 97 98 //跳轉到主頁 99 private void goHome() { 100 Intent intent = new Intent(SplashActivity.this, MainActivity.class); 101 SplashActivity.this.startActivity(intent); 102 SplashActivity.this.finish(); 103 } 104 105 //跳轉到初始頁 106 private void goGuide() { 107 Intent intent = new Intent(SplashActivity.this, GuideActivity.class); 108 SplashActivity.this.startActivity(intent); 109 SplashActivity.this.finish(); 110 } 111 112 }
2.簡單的OnPageChangeListener運用,ViewPagerAdapter的layout文件和java代碼。viewpager是google SDk中自帶的一個附加包的一個類,可以用來實現屏幕間的切換。ViewPager的適配器一般有兩種,傳入List<View> views 對應的adapter就是ViewPagerAdapter,如果傳的是fragment[] framgments的話就是FragmentPagerAdapter或者FragmentStatePagerAdapter。我傳的就是List<View>,所以用ViewPagerAdapter
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <android.support.v4.view.ViewPager android:id="@+id/viewpager" android:layout_width="match_parent" android:layout_height="match_parent" /> <!-- <LinearLayout android:id="@+id/ll" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:layout_marginBottom="24.0dp" android:orientation="horizontal" > <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:clickable="true" android:padding="15.0dip" android:src="@drawable/dot" /> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:clickable="true" android:padding="15.0dip" android:src="@drawable/dot" /> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:clickable="true" android:padding="15.0dip" android:src="@drawable/dot" /> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:clickable="true" android:padding="15.0dip" android:src="@drawable/dot" /> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:clickable="true" android:padding="15.0dip" android:src="@drawable/dot" /> </LinearLayout> --> </RelativeLayout>
1 package com.wym.dxdmallandroid; 2 3 import java.util.ArrayList; 4 import java.util.List; 5 6 import com.dxd.dxdmallandroid.R; 7 import com.wym.splansh.adapter.ViewPagerAdapter; 8 9 import android.app.Activity; 10 import android.os.Bundle; 11 import android.support.v4.view.ViewPager; 12 import android.support.v4.view.ViewPager.OnPageChangeListener; 13 import android.view.LayoutInflater; 14 import android.view.View; 15 16 /** 17 * @Version 1.0 18 * 19 * 20 */ 21 public class GuideActivity extends Activity implements OnPageChangeListener { 22 23 private ViewPager vp; 24 private ViewPagerAdapter vpAdapter; 25 private List<View> views; 26 27 // 底部小點圖片 28 //private ImageView[] dots; 29 30 // 記錄當前選中位置 31 private int currentIndex; 32 33 @Override 34 protected void onCreate(Bundle savedInstanceState) { 35 super.onCreate(savedInstanceState); 36 setContentView(R.layout.guide); 37 // 初始化頁面 38 initViews(); 39 // 初始化底部小點 40 //initDots(); 41 } 42 43 @SuppressWarnings("deprecation") 44 private void initViews() { 45 LayoutInflater inflater = LayoutInflater.from(this); 46 47 views = new ArrayList<View>(); 48 // 初始化引導圖片列表 49 views.add(inflater.inflate(R.layout.what_new_one, null)); 50 views.add(inflater.inflate(R.layout.what_new_two, null)); 51 views.add(inflater.inflate(R.layout.what_new_three, null)); 52 views.add(inflater.inflate(R.layout.what_new_four, null)); 53 views.add(inflater.inflate(R.layout.what_new_five, null)); 54 // 初始化Adapter 55 vpAdapter = new ViewPagerAdapter(views, this); 56 57 vp = (ViewPager) findViewById(R.id.viewpager); 58 vp.setAdapter(vpAdapter); 59 // 綁定回調 60 vp.setOnPageChangeListener(this); 61 } 62 63 // private void initDots() { 64 // LinearLayout ll = (LinearLayout) findViewById(R.id.ll); 65 // 66 // dots = new ImageView[views.size()]; 67 // 68 // // 循環取得小點圖片 69 // for (int i = 0; i < views.size(); i++) { 70 // dots[i] = (ImageView) ll.getChildAt(i); 71 // dots[i].setEnabled(true);// 都設為灰色 72 // } 73 // 74 // currentIndex = 0; 75 // dots[currentIndex].setEnabled(false);// 設置為白色,即選中狀態 76 // } 77 78 private void setCurrentDot(int position) { 79 if (position < 0 || position > views.size() - 1 80 || currentIndex == position) { 81 return; 82 } 83 84 // dots[position].setEnabled(false); 85 // dots[currentIndex].setEnabled(true); 86 87 currentIndex = position; 88 } 89 90 // 當滑動狀態改變時調用 91 @Override 92 public void onPageScrollStateChanged(int arg0) { 93 } 94 95 // 當當前頁面被滑動時調用 96 @Override 97 public void onPageScrolled(int arg0, float arg1, int arg2) { 98 } 99 100 // 當新的頁面被選中時調用 101 @Override 102 public void onPageSelected(int arg0) { 103 // 設置底部小點選中狀態 104 setCurrentDot(arg0); 105 } 106 107 }