0x01 前言
对于现在大部分的APP，第一次打开刚安装或更新安装的APP都会有几个引导界面，通常这几个引导页是告诉用户
APP有些什么功能或者修改了什么bug、新增了什么功能等等等。
下面就用Xamarin.Android来简单实现一下。主要用到的是ViewPager，当然也就离不开Xamarin.Android.Support.v4
如果遇到不能编译的问题，可以参考Xamarin.Android之简单的抽屉布局的出错处理方案。
0x02 页面布局编写
新建一个Android项目
添加几个简单的布局页面。
首先是添加个启动页面，splash.axml
1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout 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.support.v4.view.ViewPager 7 android:id="@+id/viewpager" 8 android:layout_width="match_parent" 9 android:layout_height="match_parent" /> 10 <LinearLayout 11 android:id="@+id/ll" 12 android:orientation="horizontal" 13 android:layout_width="wrap_content" 14 android:layout_height="wrap_content" 15 android:layout_marginBottom="24.0dip" 16 android:layout_alignParentBottom="true" 17 android:layout_centerHorizontal="true"> 18 <ImageView 19 android:layout_width="wrap_content" 20 android:layout_height="wrap_content" 21 android:layout_gravity="center_vertical" 22 android:clickable="true" 23 android:padding="15.0dip" 24 android:src="@drawable/dot" /> 25 <ImageView 26 android:layout_width="wrap_content" 27 android:layout_height="wrap_content" 28 android:layout_gravity="center_vertical" 29 android:clickable="true" 30 android:padding="15.0dip" 31 android:src="@drawable/dot" /> 32 <ImageView 33 android:layout_width="wrap_content" 34 android:layout_height="wrap_content" 35 android:layout_gravity="center_vertical" 36 android:clickable="true" 37 android:padding="15.0dip" 38 android:src="@drawable/dot" /> 39 </LinearLayout> 40 </RelativeLayout>
引导页，用了一个ViewPager，下面的线性布局是用来存放的三个点就是当前所在的引导页面。
用到的ImageView有个src指向drawable下面的dot.xml。内容如下：
1 <?xml version="1.0" encoding="utf-8" ?> 2 <selector 3 xmlns:android="http://schemas.android.com/apk/res/android"> 4 <item android:state_enabled="true" android:drawable="@drawable/dark_dot" /> 5 <item android:state_enabled="false" android:drawable="@drawable/white_dot" /> 6 </selector>
然后是3个引导页的具体内容。
guide_first.axml
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:layout_width="match_parent" 4 android:layout_height="match_parent" 5 android:orientation="vertical"> 6 <TextView 7 android:layout_width="match_parent" 8 android:layout_height="match_parent" 9 android:gravity="center" 10 android:text="guide---first" 11 android:textSize="30sp" /> 12 </LinearLayout>
guide_second.axml
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:layout_width="match_parent" 4 android:layout_height="match_parent" 5 android:orientation="vertical"> 6 <TextView 7 android:layout_width="match_parent" 8 android:layout_height="match_parent" 9 android:gravity="center" 10 android:text="guide--second" 11 android:textSize="30sp" /> 12 </LinearLayout>
guide_third.axml
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:layout_width="match_parent" 4 android:layout_height="match_parent" 5 android:orientation="vertical"> 6 <TextView 7 android:layout_width="match_parent" 8 android:layout_height="wrap_content" 9 android:layout_marginTop="250dp" 10 android:gravity="center" 11 android:text="guide--third" 12 android:textSize="30sp" /> 13 <Button 14 android:id="@+id/startBtn" 15 android:layout_width="wrap_content" 16 android:layout_height="wrap_content" 17 android:layout_alignParentBottom="true" 18 android:layout_centerHorizontal="true" 19 android:text="begin now" 20 android:layout_gravity="center" 21 android:layout_marginBottom="55dp" /> 22 </LinearLayout>
这里没有用图片来展示，就简单的用了文字，没有设计师设计，so....随意一点。
最后是Main.axml
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:layout_width="fill_parent" 4 android:layout_height="fill_parent"> 5 <TextView 6 android:layout_width="fill_parent" 7 android:layout_height="wrap_content" 8 android:gravity="center" 9 android:layout_gravity="center_vertical" 10 android:text="the main page" 11 android:textSize="30sp" /> 12 </LinearLayout>
0x03 Activity的编写
首先SplashActivity
1 using Android.App;
2 using Android.Content;
3 using Android.Content.PM;
4 using Android.OS;
5 using Android.Widget;
6 namespace GuideDemo
7 {
8 [Activity(Label = "GuideDemo", MainLauncher = true, Icon = "@drawable/icon")]
9 public class SplashActivity : Activity
10 {
11 protected override void OnCreate(Bundle savedInstanceState)
12 {
13 base.OnCreate(savedInstanceState);
14 SetContentView(Resource.Layout.splash);
15 //version‘s infomation
16 var version = PackageManager.GetPackageInfo(this.PackageName, PackageInfoFlags.MatchAll).VersionName;
17 var tvVersion = FindViewById<TextView>(Resource.Id.tv_version);
18 tvVersion.Text = "Version " + version;
19 //get infomation from shared preferences
20 var sp = GetSharedPreferences("app_setting", FileCreationMode.Private);
21 new Handler().PostDelayed(() =>
22 {
23 Intent intent;
24 //first or not
25 if (sp.GetString("version", "") != version)
26 {
27 intent = new Intent(this, typeof(GuideActivity));
28 }
29 else
30 {
31 intent = new Intent(this, typeof(MainActivity));
32 }
33 StartActivity(intent);
34 this.Finish();
35 }, 1000);
36 }
37 }
38 }
把是否是第一次开启信息存放到sharepreferences，我这里主要是通过版本号来控制。
然后是GuideActivity
1 using Android.App;
2 using Android.Content;
3 using Android.Content.PM;
4 using Android.OS;
5 using Android.Support.V4.View;
6 using Android.Views;
7 using Android.Widget;
8 using System;
9 using System.Collections.Generic;
10 using static Android.Support.V4.View.ViewPager;
11 namespace GuideDemo
12 {
13 [Activity(Label = "GuideActivity")]
14 public class GuideActivity : Activity
15 {
16 private ViewPager viewPager;
17
18 private List<View> views;
19
20 private View view1, view2, view3;
21
22 private Button btnStart;
23
24 private ImageView[] dots;
25
26 private int currentIndex;
27 private LinearLayout ll;
28 protected override void OnCreate(Bundle savedInstanceState)
29 {
30 base.OnCreate(savedInstanceState);
31 SetContentView(Resource.Layout.activity_guide);
32 viewPager = FindViewById<ViewPager>(Resource.Id.viewpager);
33 //the layout
34 LayoutInflater mLi = LayoutInflater.From(this);
35 view1 = mLi.Inflate(Resource.Layout.guide_first, null);
36 view2 = mLi.Inflate(Resource.Layout.guide_second, null);
37 view3 = mLi.Inflate(Resource.Layout.guide_third, null);
38 views = new List<View>();
39 views.Add(view1);
40 views.Add(view2);
41 views.Add(view3);
42
43 //the adapter
44 viewPager.Adapter = new ViewPagerAdapter(views);
45 //page selected
46 viewPager.PageSelected += PageSelected;
47 ll = FindViewById<LinearLayout>(Resource.Id.ll);
48 //the dot infomation
49 dots = new ImageView[3];
50 for (int i = 0; i < views.Count; i++)
51 {
52 dots[i] = (ImageView)ll.GetChildAt(i);
53 dots[i].Enabled = false;
54 }
55 dots[0].Enabled = true;
56 //the button
57 btnStart = view3.FindViewById<Button>(Resource.Id.startBtn);
58 btnStart.Click += Start;
59 }
60 /// <summary>
61 /// page selected
62 /// </summary>
63 /// <param name="sender"></param>
64 /// <param name="e"></param>
65 private void PageSelected(object sender, PageSelectedEventArgs e)
66 {
67 ll = FindViewById<LinearLayout>(Resource.Id.ll);
68 for (int i = 0; i < views.Count; i++)
69 {
70 dots[i] = (ImageView)ll.GetChildAt(i);
71 dots[i].Enabled = false;
72 }
73 dots[e.Position].Enabled = true;
74 }
75 /// <summary>
76 /// start the main page
77 /// </summary>
78 /// <param name="sender"></param>
79 /// <param name="e"></param>
80 private void Start(object sender, EventArgs e)
81 {
82 //get infomation from shared preferences
83 var sp = GetSharedPreferences("app_setting", FileCreationMode.Private);
84 //the editor
85 var editor = sp.Edit();
86 //update
87 editor.PutString("version", PackageManager.GetPackageInfo(this.PackageName, PackageInfoFlags.MatchAll).VersionName).Commit() ;
88 StartActivity(typeof(MainActivity));
89 this.Finish();
90 }
91 }
92 }
主要是ViewPager处理、页面切换点的处理以及begin now 按钮的点击事件。
其中有个ViewPagerAdapter要自己实现
1 using Android.Support.V4.View;
2 using Android.Views;
3 using System.Collections.Generic;
4 namespace GuideDemo
5 {
6 internal class ViewPagerAdapter : PagerAdapter
7 {
8 private List<View> views;
9 public ViewPagerAdapter(List<View> views)
10 {
11 this.views = views;
12 }
13 public override int Count
14 {
15 get
16 {
17 if (views != null)
18 {
19 return views.Count;
20 }
21 else
22 {
23 return 0;
24 }
25 }
26 }
27 public override bool IsViewFromObject(View view, Java.Lang.Object objectValue)
28 {
29 return view== objectValue;
30 }
31 public override void DestroyItem(ViewGroup container, int position, Java.Lang.Object objectValue)
32 {
33 container.RemoveView(views[position]);
34 }
35 public override Java.Lang.Object InstantiateItem(ViewGroup container, int position)
36 {
37 container.AddView(views[position], 0);
38 return views[position];
39 }
40 }
41 }
最后是MainActivity
1 using Android.App;
2 using Android.OS;
3 namespace GuideDemo
4 {
5 [Activity(Label = "GuideDemo")]
6 public class MainActivity : Activity
7 {
8 protected override void OnCreate(Bundle bundle)
9 {
10 base.OnCreate(bundle);
11
12 SetContentView(Resource.Layout.Main);
13 }
14 }
15 }
到这里就OK了，下面就来看看效果。
0x04 效果图
时间： 2024-10-24 12:07:46