一直以来，无论是博客、新闻、还是推荐用户列表。只能加载固定的数量，也没有刷新功能。
为了实现这个功能，也试过很多第三方的开源控件，如pulltorefreshlistvie等。无意中发现了google官方发布了一个新的控件（swiperefreshlayout），支持下拉刷新，这个控件在google应用中都有出现过。效果也是非常的不错。
具体的使用方法及代码如下：
1 <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
2 android:layout_width="fill_parent"
3 android:layout_height="fill_parent"
4 android:orientation="vertical" >
5
6 <android.support.v4.widget.swiperefreshlayout
7 android:id="@ id/swiperefreshlayouthomeblog"
8 android:layout_width="match_parent"
9 android:layout_height="match_parent" >
10
11 <listview
12 android:id="@ id/listviewhomeblog"
13 android:layout_width="match_parent"
14 android:layout_height="wrap_content" >
15 listview>
16 android.support.v4.widget.swiperefreshlayout>
17
18 linearlayout> 需要注意的一点就是swiperefreshlayout中只能包含一个控件。其他属性和其他layout大体相同。
第一点，下拉刷新：
使用的话，需要在activity或者fragment中导入并实现android.support.v4.widget.swiperefreshlayout.onrefreshlistener接口，并且要重写onrefresh()方法。
第二点，分页处理：
需要实现onscrolllistener接口，并且重写和onscrollstatechangedonscroll和两个方法。
具体代码如下
1 package com.arlen.cnblogs.fragment;
2
3 import java.util.arraylist;
4 import java.util.list;
5
6 import android.content.intent;
7 import android.os.bundle;
8 import android.support.v4.app.fragment;
9 import android.support.v4.widget.swiperefreshlayout;
10 import android.support.v4.widget.swiperefreshlayout.onrefreshlistener;
11 import android.util.log;
12 import android.view.layoutinflater;
13 import android.view.view;
14 import android.view.viewgroup;
15 import android.widget.abslistview;
16 import android.widget.abslistview.onscrolllistener;
17 import android.widget.adapterview;
18 import android.widget.adapterview.onitemclicklistener;
19 import android.widget.adapterview.onitemlongclicklistener;
20 import android.widget.listview;
21
22 import com.arlen.cnblogs.blogactivity;
23 import com.arlen.cnblogs.r;
24 import com.arlen.cnblogs.adapter.bloglistadapter;
25 import com.arlen.cnblogs.entity.blog;
26 import com.arlen.cnblogs.task.bloglisttask;
27 import com.arlen.cnblogs.utils.appmacros;
28 import com.arlen.cnblogs.utils.apputils;
29
30 public class bloghomefragment extends fragment implements
31 onitemlongclicklistener, onitemclicklistener, onrefreshlistener,
32 onscrolllistener {
33 private static final string tag = bloghomefragment.class.getsimplename();
34
35 private swiperefreshlayout swiperefreshlayout;
36 private listview listview;
37
38 private bloglistadapter adapter;
39
40 private string path;
41 private int pagesize;
42 private int pageindex = 1;
43 private list bloglist;
44
45 private int lastvisibleindex;
46 private int maxvisibleindex = 400;
47
48 private intent intent;
49
50 public bloghomefragment() {
51 super();
52 }
53
54 @override
55 public void oncreate(bundle savedinstancestate) {
56 super.oncreate(savedinstancestate);
57 log.i(tag, "oncreate");
58 }
59
60 @override
61 public view oncreateview(layoutinflater inflater, viewgroup container,
62 bundle savedinstancestate) {
63 log.i(tag, "oncreateview");
64 view rootview = inflater.inflate(r.layout.fragment_blog_home,
65 container, false);
66 return rootview;
67 }
68
69 @override
70 public void onviewcreated(view view, bundle savedinstancestate) {
71 super.onviewcreated(view, savedinstancestate);
72 log.i(tag, "onviewcreated");
73 initcomponent();
74 initdata();
75 }
76
77 @override
78 public void onitemclick(adapterview parent, view view, int position,
79 long id) {
80 log.i(tag, "onitemclick -- " position);
81 showblogitem(bloglist.get(position));
82 }
83
84 @override
85 public boolean onitemlongclick(adapterview parent, view view,
86 int position, long id) {
87 log.i(tag, "onitemlongclick -- " position);
88 return false;
89 }
90
91 @override
92 public void onrefresh() {
93 new bloglisttask(bloglist, swiperefreshlayout, adapter).execute(path,
94 "refresh");
95 }
96
97 @override
98 public void onscrollstatechanged(abslistview view, int scrollstate) {
99 if (adapter.getcount() < maxvisibleindex) {
100 if (scrollstate == onscrolllistener.scroll_state_idle
101 && lastvisibleindex == adapter.getcount() - 1) {
102
103 pageindex ;
104 initpath(pageindex);
105 swiperefreshlayout.setrefreshing(true);
106 new bloglisttask(bloglist, swiperefreshlayout, adapter)
107 .execute(path, "loadmore");
108 }
109 } else {
110 // toast.maketext(getactivity(), "最后一页!",
111 // toast.length_short).show();
112 }
113 }
114
115 @override
116 public void onscroll(abslistview view, int firstvisibleitem,
117 int visibleitemcount, int totalitemcount) {
118 lastvisibleindex = firstvisibleitem visibleitemcount - 1;
119 }
120
121 private void initcomponent() {
122 swiperefreshlayout = (swiperefreshlayout) this.getactivity()
123 .findviewbyid(r.id.swiperefreshlayouthomeblog);
124 swiperefreshlayout.setonrefreshlistener(this);
125 swiperefreshlayout.setcolorschemeresources(
126 android.r.color.holo_blue_bright,
127 android.r.color.holo_green_light,
128 android.r.color.holo_orange_light,
129 android.r.color.holo_red_light);
130
131 listview = (listview) this.getactivity().findviewbyid(
132 r.id.listviewhomeblog);
133 listview.setonitemclicklistener(this);
134 listview.setonitemlongclicklistener(this);
135 listview.setonscrolllistener(this);
136 }
137
138 private void initdata() {
139 bloglist = new arraylist();
140 adapter = new bloglistadapter(getactivity(), bloglist);
141 listview.setadapter(adapter);
142
143 initpath(1);
144 swiperefreshlayout.setrefreshing(true);
145 new bloglisttask(bloglist, swiperefreshlayout, adapter).execute(path,
146 "init");
147 }
148
149 private void initpath(int pageindex) {
150 // http://wcf.open.cnblogs.com/blog/sitehome/paged/{pageindex}/{pagesize}
151 path = appmacros.recent_blogs_paged;
152 pagesize = appmacros.page_size;
153 path = path.replace("{pageindex}", "" pageindex);
154 path = path.replace("{pagesize}", "" pagesize);
155
156 log.i(tag, "pageindex：" pageindex);
157 }
158
159 private void showblogitem(blog blogentry) {
160 intent = new intent(this.getactivity(), blogactivity.class);
161
162 if (blogentry.getauthoravatar() != null) {
163 intent.putextra("avatar", blogentry.getauthoravatar().tostring());
164 } else {
165 intent.putextra("avatar", "");
166 }
167 intent.putextra("title", blogentry.getblogtitle());
168 intent.putextra("author", blogentry.getauthorname());
169 intent.putextra("published",
170 apputils.parsedatetostring(blogentry.getpublisheddatedate()));
171 intent.putextra("id", blogentry.getblogid());
172 intent.putextra("link", blogentry.getblogtitle());
173
174 startactivity(intent);
175 }
176 } 在之前的项目中，使用了handler thread来加载数据刷新控件，但是感觉代码比较混乱。在新的版本中使用了asynctask来替换。具体实现如下：
1 package com.arlen.cnblogs.task;
2
3 import java.util.arraylist;
4 import java.util.list;
5
6 import com.arlen.cnblogs.adapter.bloglistadapter;
7 import com.arlen.cnblogs.entity.blog;
8 import com.arlen.cnblogs.utils.apputils;
9 import com.arlen.cnblogs.utils.httputil;
10
11 import android.os.asynctask;
12 import android.support.v4.widget.swiperefreshlayout;
13
14 public class bloglisttask extends asynctask {
15 private list bloglist;
16 private list newlist = new arraylist();
17 private swiperefreshlayout swiperefreshlayout;
18 private bloglistadapter adapter;
19
20 public bloglisttask(list bloglist,
21 swiperefreshlayout swiperefreshlayout, bloglistadapter adapter) {
22 super();
23 this.bloglist = bloglist;
24 this.swiperefreshlayout = swiperefreshlayout;
25 this.adapter = adapter;
26 }
27
28 protected void doinbackground(string... params) {
29
30 newlist = httputil.getbloglist(params[0]);
31
32 if (params[1].equals("init")) {
33 bloglist.addall(newlist);
34 } else if (params[1].equals("refresh")) {
35 newlist.addall(bloglist);
36 apputils.removeduplicate(newlist);
37 bloglist.clear();
38 bloglist.addall(newlist);
39 } else if (params[1].equals("loadmore")) {
40 bloglist.addall(newlist);
41 apputils.removeduplicate(bloglist);
42 }
43 return null;
44 }
45
46 @override
47 protected void onpreexecute() {
48 super.onpreexecute();
49 newlist.clear();
50 }
51
52 @override
53 protected void onpostexecute(void result) {
54 super.onpostexecute(result);
55
56 swiperefreshlayout.setrefreshing(false);
57 adapter.updatabloglist(bloglist);
58 adapter.notifydatasetchanged();
59 }
60
61 } 刷新数据后可能会出现数据重复，要去除重复，首先要在类中重写equals（）方法，应为要考虑到不同类型，使用了泛型方法来对user、blog、news和comment来进行去重。具体如下：
1 @override
2 public boolean equals(object object) {
3 if (object instanceof blog) {
4 blog blog = (blog) object;
5 return string.valueof(blog.getblogid()).equals(
6 string.valueof(this.getblogid()));
7 } else {
8 return super.equals(object);
9 }
10 } 1 public static void removeduplicate(list list) {
2 for (int i = 0; i < list.size(); i ) {
3 for (int j = i 1; j < list.size(); j ) {
4 if (list.get(i).equals(list.get(j))) {
5 list.remove(j);
6 }
7 }
8 }
9 } 项目地址：https://github.com/zhangtingkuo/androidcnblogs
转载于:https://www.cnblogs.com/zhangtingkuo/p/4052623.html
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