现在很多app一打开就是一个viewpager，然后可以用手指滑，每滑一次就换一张图，底下还会有圈圈表示说现在滑到第几章~
通常这些图片都是放功能简介或是使用教学之类的，我的需求很简单，就是上面提到的那样而已。
有两种做法，一种是找现有套件，查了一堆资料每个都跟我推荐viewpagerindicator这套，我之前也看过这套，只是看起来需要有fragment再加上google play范例好像载不到了，所以只好自己实做一个。
viewpager的实作可参考android viewpager使用详解里面的程序码:
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
@overrideprotected void oncreate(bundle savedinstancestate) {
super.oncreate(savedinstancestate);
setcontentview(r.layout.activity_intro);
mviewpager = (viewpager) findviewbyid(r.id.viewpager);
final layoutinflater minflater = getlayoutinflater().from(this);
view v1 = minflater.inflate(r.layout.intro_layout_1, null);
view v2 = minflater.inflate(r.layout.intro_layout_2, null);
view v3 = minflater.inflate(r.layout.intro_layout_3, null);
view v4 = minflater.inflate(r.layout.intro_layout_4, null);
viewlist = new arraylist<view>();
viewlist.add(v1);
viewlist.add(v2);
viewlist.add(v3);
viewlist.add(v4);
mviewpager.setadapter(new myviewpageradapter(viewlist));
mviewpager.setcurrentitem(0);}
myviewpageradapter
public class myviewpageradapter extends pageradapter {
private list<view> mlistviews;
public myviewpageradapter(list<view> mlistviews) {
this.mlistviews = mlistviews;
}
@override
public void destroyitem(viewgroup container, int position, object object) {
container.removeview((view) object);
}
@override
public object instantiateitem(viewgroup container, int position) {
view view = mlistviews.get(position);
container.addview(view);
return view;
}
@override
public int getcount() {
return mlistviews.size();
}
@override
public boolean isviewfromobject(view arg0, object arg1) {
return arg0==arg1;
}}
|
这样子你就有一个viewpager了
下面我们来具体看一下viewpager的用法：
一、viewpager创建步骤
① 在xml布局中加入android.support.v4.view.viewpager
② 加载显示的页卡将layout布局转换为view对象
(1)
|
1
2
|
layoutinflater lf getlayoutinflater().from(this);
lf.inflate(resource,root);
|
(2)
|
1
|
view.inflate(context,resource,root);
|
③ 配置adapter（三种adapter）
(1)pageradapter 数据源：list<view>
(2)fragmentpageradapter 数据源：list<fragment>
(3)fragmentstatepageradapter 数据源：list<fragment>
二、代码示例
新建四个fragment和他们的布局下面是mainactivity的xml布局：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
|
<android.support.v4.view.viewpager
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center" >
<android.support.v4.view.pagertabstrip
android:id="@+id/tab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top" >
</android.support.v4.view.pagertabstrip>
<!-- 底部显示标题与上面的顶部显示不能同时出现
<android.support.v4.view.pagertitlestrip
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom" >
</android.support.v4.view.pagertitlestrip>
-->
</android.support.v4.view.viewpager>
|
第一种pageradapter
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
|
public class mypageradapter extends pageradapter {
private list<view> viewlist;
private list<string> titlelist;
public mypageradapter(list<view> viewlist,list<string> titlelist){
this.viewlist = viewlist;
this.titlelist = titlelist;
}
/**
* 返回页卡的数量
*/
@override
public int getcount() {
return viewlist.size();
}
/**
* view是否来自对象
*/
@override
public boolean isviewfromobject(view arg0, object arg1) {
return arg0==arg1;
}
/**
* 实例化一个页卡
*/
@override
public object instantiateitem(viewgroup container, int position) {
container.addview(viewlist.get(position));
return viewlist.get(position);
}
/**
* 销毁一个页卡
*/
@override
public void destroyitem(viewgroup container, int position, object object) {
container.removeview(viewlist.get(position));
}
/**
* 设置viewpager的标题
*/
@override
public charsequence getpagetitle(int position) {
return titlelist.get(position);
}
}
|
第二种fragmentpageradapter
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
|
public class myfragmentpageradapter extends fragmentpageradapter {
private list<fragment> fraglist;
private list<string> titlelist;
public myfragmentpageradapter(fragmentmanager fm,list<fragment> fraglist,list<string> titlelist) {
super(fm);
this.fraglist = fraglist;
this.titlelist = titlelist;
}
@override
public fragment getitem(int arg0) {
return fraglist.get(arg0);
}
@override
public charsequence getpagetitle(int position) {
return titlelist.get(position);
}
@override
public int getcount() {
return fraglist.size();
}
}
|
第三种fragmentstatepageradapter（该适配器可以动态销毁fragment）
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
public class myfragmentpageradapter2 extends fragmentstatepageradapter {//该适配器可以动态销毁
private list<fragment> fraglist;
private list<string> titlelist;
public myfragmentpageradapter2(fragmentmanager fm,list<fragment> fraglist,list<string> titlelist) {
super(fm);
this.fraglist = fraglist;
this.titlelist = titlelist;
}
@override
public fragment getitem(int arg0) {
return fraglist.get(arg0);
}
@override
public charsequence getpagetitle(int position) {
return titlelist.get(position);
}
@override
public int getcount() {
return fraglist.size();
}
@override
public object instantiateitem(viewgroup arg0, int arg1) {
return super.instantiateitem(arg0, arg1);
}
@override
public void destroyitem(viewgroup container, int position, object object) {
super.destroyitem(container, position, object);
}
}
|
mainactivity里使用getsupportfragmentmanager()该activity必须继承fragmentactivity：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
public class mainactivity extends fragmentactivity implements onpagechangelistener{
private list<view> viewlist;
private list<string> titlelist;
private viewpager pager;
private pagertabstrip tab;//顶部标题
private list<fragment> fraglist;
@override
protected void oncreate(bundle savedinstancestate) {
super.oncreate(savedinstancestate);
setcontentview(r.layout.activity_main);
viewlist = new arraylist<view>();
titlelist = new arraylist<string>();
tab = (pagertabstrip) findviewbyid(r.id.tab);
view view1 = view.inflate(this,r.layout.view1,null);
view view2 = view.inflate(this,r.layout.view2,null);
view view3 = view.inflate(this,r.layout.view3,null);
view view4 = view.inflate(this,r.layout.view4,null);
viewlist.add(view1);
viewlist.add(view2);
viewlist.add(view3);
viewlist.add(view4);
fraglist = new arraylist<fragment>();
fraglist.add(new fragment1());
fraglist.add(new fragment2());
fraglist.add(new fragment3());
fraglist.add(new fragment4());
//为viewpager页卡设置标题
titlelist.add("第一页");
titlelist.add("第二页");
titlelist.add("第三页");
titlelist.add("第四页");
//为pagertabstrip设置一些属性
tab.setbackgroundcolor(color.white);
tab.setdrawfullunderline(false);
tab.settabindicatorcolor(color.blue);
pager = (viewpager) findviewbyid(r.id.pager);
//mypageradapter adapter = new mypageradapter(viewlist,titlelist);
//myfragmentpageradapter adapter = new myfragmentpageradapter(getsupportfragmentmanager(), fraglist, titlelist);
/**
* 使用getsupportfragmentmanager()该activity必须继承fragmentactivity
*/
myfragmentpageradapter2 adapter = new myfragmentpageradapter2(getsupportfragmentmanager(), fraglist, titlelist);
pager.setadapter(adapter);
pager.setonpagechangelistener(this);
}
@override
public void onpagescrollstatechanged(int arg0) {
}
@override
public void onpagescrolled(int arg0, float arg1, int arg2) {
}
@override
public void onpageselected(int arg0) {
toast.maketext(this,"当前是第"+(arg0+1)+"个界面", 0).show();
}
}
|