安卓开发-实现第一次进入软件的引导页

最近做的APP接近尾声了，就是些优化工作了，

我们都知道现在的APP都会有引导页，就是安装之后第一次打开才显示的引导页面（介绍这个软件的几张可以切换的图）

自己做了一下，结合之前学过的

安卓开发_慕课网_ViewPager切换动画（3.0版本以上有效果）

 

思路很简单，APP的主界面还是作为主Activity，只要新添加一个类来判断是不是第一次打开APP

设主activity 名字为：MainActivity.java   判断是不是第一次打开APP且实现引导页面的类 LoginActivity ，另外还需要一个类 这是安卓开发_慕课网_ViewPager切换动画（3.0版本以上有效果）中用到的 ZoomOutPageTransformer.java

1.在主activity中,在一开始 先跳转到LoginActivity类中

 1  protected void onCreate(Bundle savedInstanceState) {

 2         super.onCreate(savedInstanceState);

 3         requestWindowFeature(Window.FEATURE_NO_TITLE);

 4         setContentView(R.layout.activity_main);

 5         startActivity(new Intent(MainActivity.this, LoginActivity.class)); //跳转到LoginActivity类中

 6       //初始化

 7         init();

 8         initEvent();

 9         //默认显示第一个功能的界面(微信界面)

10         setSelect(0);

11     }

2.在LoginActivity类中判断是不是第一次打开，如果是，则显示ViewPager切换动画效果

如果不是，则执行finish();语句，直接结束这个Activity  自然的就回到了主Activity中了

 

LoginActivity代码

 1 package com.example.qunxiong;

 2 

 3 import java.io.OutputStream;

 4 import java.util.ArrayList;

 5 import java.util.List;

 6 

 7 

 8 

 9 import android.app.Activity;

10 import android.content.Context;

11 import android.content.Intent;

12 import android.content.SharedPreferences;

13 import android.content.SharedPreferences.Editor;

14 import android.os.Bundle;

15 import android.support.v4.view.PagerAdapter;

16 import android.support.v4.view.ViewPager;

17 import android.view.View;

18 import android.view.ViewGroup;

19 import android.view.View.OnClickListener;

20 import android.widget.Button;

21 import android.widget.ImageView;

22 import android.widget.ImageView.ScaleType;

23 

24 public class LoginActivity extends Activity {

25     private ViewPager mviewpager; //控件

26     private int[] mImgIds = new int[]{R.drawable.bg_rank_shenqi_0,R.drawable.bg_rank_shenqi_1,R.drawable.bg_rank_shenqi_10};//初始化图片

27     private List<ImageView> mImages = new ArrayList<ImageView>();

28     private Button jump;

29      private SharedPreferences preferences;

30       private Editor editor;

31       private OutputStream os;

32       @Override

33       protected void onCreate(Bundle savedInstanceState) {

34        super.onCreate(savedInstanceState);

35        setContentView(R.layout.login);

36        preferences = getSharedPreferences("phone", Context.MODE_PRIVATE);

37        jump = (Button) findViewById(R.id.jump);

38        jump.setOnClickListener(new OnClickListener() {    

39             @Override

40             public void onClick(View v) {

41                 // TODO Auto-generated method stub

42                 finish();

43             }

44         });

45        //判断是不是首次登录，

46        if (preferences.getBoolean("firststart", true)) {

47         editor = preferences.edit();

48         //将登录标志位设置为false，下次登录时不在显示首次登录界面

49         editor.putBoolean("firststart", false);

50         editor.commit();

51         mviewpager = (ViewPager) findViewById(R.id.id_viewpager);

52         //为ViewPage切换添加动画效果(3.0以上版本才可以有效果)

53         mviewpager.setPageTransformer(true, new ZoomOutPageTransformer());

54         

55         mviewpager.setAdapter(new PagerAdapter() {

56             

57             @Override

58             public Object instantiateItem(View container, int position) {

59                 ImageView imageview = new ImageView(LoginActivity.this);

60                 imageview.setImageResource(mImgIds[position]);

61                 imageview.setScaleType(ScaleType.CENTER_CROP); //设置图片不变形

62                 ((ViewGroup) container).addView(imageview);

63                 mImages.add(imageview);

64                 return imageview;

65             };

66             @Override

67             public void destroyItem(View container, int position, Object object) {

68                 // TODO Auto-generated method stub

69                 

70                 ((ViewPager) container).removeView(mImages.get(position));

71             }

72             public boolean isViewFromObject(View view, Object object) {

73                 // TODO Auto-generated method stub

74                 return view == object;

75             }

76             

77             @Override

78             public int getCount() {                   //返回图片个数

79                 // TODO Auto-generated method stub

80                 return mImgIds.length;

81             }

82         });

83        }

84        else 

85        {

86            finish();

87        }

88        

89       }

90 }

91       

 切换动画效果代码 

ZoomOutPageTransformer.java

 1 package com.example.qunxiong;

 2 

 3 import android.annotation.SuppressLint;

 4 import android.support.v4.view.ViewPager;

 5 import android.view.View;

 6 

 7 public class ZoomOutPageTransformer implements ViewPager.PageTransformer {

 8     private static final float MIN_SCALE = 0.85f;

 9     private static final float MIN_ALPHA = 0.5f;

10     

11     @SuppressLint("NewApi") public void transformPage(View view, float position) {

12         int pageWidth = view.getWidth();

13         int pageHeight = view.getHeight();

14 

15         if (position < -1) { // [-Infinity,-1)

16             // This page is way off-screen to the left.

17             view.setAlpha(0);

18 

19         } else if (position <= 1) { // [-1,1]

20             // Modify the default slide transition to shrink the page as well

21             float scaleFactor = Math.max(MIN_SCALE, 1 - Math.abs(position));

22             float vertMargin = pageHeight * (1 - scaleFactor) / 2;

23             float horzMargin = pageWidth * (1 - scaleFactor) / 2;

24             if (position < 0) {

25                 view.setTranslationX(horzMargin - vertMargin / 2);

26             } else {

27                 view.setTranslationX(-horzMargin + vertMargin / 2);

28             }

29 

30             // Scale the page down (between MIN_SCALE and 1)

31             view.setScaleX(scaleFactor);

32             view.setScaleY(scaleFactor);

33 

34             // Fade the page relative to its size.

35             view.setAlpha(MIN_ALPHA +

36                     (scaleFactor - MIN_SCALE) /

37                     (1 - MIN_SCALE) * (1 - MIN_ALPHA));

38 

39         } else { // (1,+Infinity]

40             // This page is way off-screen to the right.

41             view.setAlpha(0);

42         }

43     }

44 }

View Code