ViewPager+Fragmrnt最简单结合方法
Fragment和ViewPager
本博文系本菜鸟第一次博文展示,有错误之处请虽然提出
FragmentPagerAdapter
谷歌官方提供了这么一个adapter(FragmentPagerAdapter),
- 与正常的PagerAdapter相比:
用FragmentPagerAdapter时:仅仅须要复写getItem(int position),getCount()两个方法
public MyPagerAdapter(FragmentManager fm) {
super(fm)
}
@Override
public Fragment getItem(int position) {
return null;
}
@Override
public int getCount() {
return 0;
}
- 用PagerAdapter时:通常要复写大部分方法:
@Override
public int getCount() {
return 0;
}
@Override
public boolean isViewFromObject(View view, Object object) {
return false;
}
public MyPagerAdapter() {
super();
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
return super.instantiateItem(container, position);
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
super.destroyItem(container, position, object);
}
以下附上FragmentPagerAdapter的代码
/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.support.v4.app;
import android.os.Parcelable;
import android.support.v4.view.PagerAdapter;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
/**
* Implementation of {@link android.support.v4.view.PagerAdapter} that
* represents each page as a {@link Fragment} that is persistently
* kept in the fragment manager as long as the user can return to the page.
*
* <p>This version of the pager is best for use when there are a handful of
* typically more static fragments to be paged through, such as a set of tabs.
* The fragment of each page the user visits will be kept in memory, though its
* view hierarchy may be destroyed when not visible. This can result in using
* a significant amount of memory since fragment instances can hold on to an
* arbitrary amount of state. For larger sets of pages, consider
* {@link FragmentStatePagerAdapter}.
*
* <p>When using FragmentPagerAdapter the host ViewPager must have a
* valid ID set.</p>
*
* <p>Subclasses only need to implement {@link #getItem(int)}
* and {@link #getCount()} to have a working adapter.
*
* <p>Here is an example implementation of a pager containing fragments of
* lists:
*
* {@sample development/samples/Support4Demos/src/com/example/android/supportv4/app/FragmentPagerSupport.java
* complete}
*
* <p>The <code>R.layout.fragment_pager</code> resource of the top-level fragment is:
*
* {@sample development/samples/Support4Demos/res/layout/fragment_pager.xml
* complete}
*
* <p>The <code>R.layout.fragment_pager_list</code> resource containing each
* individual fragment's layout is:
*
* {@sample development/samples/Support4Demos/res/layout/fragment_pager_list.xml
* complete}
*/
public abstract class FragmentPagerAdapter extends PagerAdapter {
private static final String TAG = "FragmentPagerAdapter";
private static final boolean DEBUG = false;
private final FragmentManager mFragmentManager;
private FragmentTransaction mCurTransaction = null;
private Fragment mCurrentPrimaryItem = null;
public FragmentPagerAdapter(FragmentManager fm) {
mFragmentManager = fm;
}
/**
* Return the Fragment associated with a specified position.
*/
public abstract Fragment getItem(int position);
@Override
public void startUpdate(ViewGroup container) {
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
if (mCurTransaction == null) {
mCurTransaction = mFragmentManager.beginTransaction();
}
final long itemId = getItemId(position);
// Do we already have this fragment?
String name = makeFragmentName(container.getId(), itemId);
Fragment fragment = mFragmentManager.findFragmentByTag(name);
if (fragment != null) {
if (DEBUG) Log.v(TAG, "Attaching item #" + itemId + ": f=" + fragment);
mCurTransaction.attach(fragment);
} else {
fragment = getItem(position);
if (DEBUG) Log.v(TAG, "Adding item #" + itemId + ": f=" + fragment);
mCurTransaction.add(container.getId(), fragment,
makeFragmentName(container.getId(), itemId));
}
if (fragment != mCurrentPrimaryItem) {
fragment.setMenuVisibility(false);
fragment.setUserVisibleHint(false);
}
return fragment;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
if (mCurTransaction == null) {
mCurTransaction = mFragmentManager.beginTransaction();
}
if (DEBUG) Log.v(TAG, "Detaching item #" + getItemId(position) + ": f=" + object
+ " v=" + ((Fragment)object).getView());
mCurTransaction.detach((Fragment)object);
}
@Override
public void setPrimaryItem(ViewGroup container, int position, Object object) {
Fragment fragment = (Fragment)object;
if (fragment != mCurrentPrimaryItem) {
if (mCurrentPrimaryItem != null) {
mCurrentPrimaryItem.setMenuVisibility(false);
mCurrentPrimaryItem.setUserVisibleHint(false);
}
if (fragment != null) {
fragment.setMenuVisibility(true);
fragment.setUserVisibleHint(true);
}
mCurrentPrimaryItem = fragment;
}
}
@Override
public void finishUpdate(ViewGroup container) {
if (mCurTransaction != null) {
mCurTransaction.commitAllowingStateLoss();
mCurTransaction = null;
mFragmentManager.executePendingTransactions();
}
}
@Override
public boolean isViewFromObject(View view, Object object) {
return ((Fragment)object).getView() == view;
}
@Override
public Parcelable saveState() {
return null;
}
@Override
public void restoreState(Parcelable state, ClassLoader loader) {
}
/**
* Return a unique identifier for the item at the given position.
*
* <p>The default implementation returns the given position.
* Subclasses should override this method if the positions of items can change.</p>
*
* @param position Position within this adapter
* @return Unique identifier for the item at position
*/
public long getItemId(int position) {
return position;
}
private static String makeFragmentName(int viewId, long id) {
return "android:switcher:" + viewId + ":" + id;
}
}
在代码中能够看出来,谷歌官方的api已经对Fragment的生命周期进行了一定的管理 大大的方便了有这样的须要的程序员们
本菜鸟在开发过程中同一时候用了ViewPager和Fragment打造首页展示页面 可是之前封装的Fragmrnt在使用过程中发生了一些错误
之前封装过一个BaseFragment来帮助自己减轻代码负担, 封装的时候并没实用v4包的Fragment
注意事项:该api相应的Fragment必须是v4包的Fragment 假设不是的话会报错,请注意.
本人博文:转载请注明 http://blog.csdn.net/qq_25436769/article/details/50765557
ViewPager+Fragmrnt最简单结合方法的更多相关文章
- 非常简单的方法实现ViewPager自动循环轮播
非常简单的方法实现ViewPager自动循环轮播,见红色代码部分,其它的代码可以忽略不看. 简洁高效是我解决问题的首要出发点. package com.shuivy.happylendandreadb ...
- MySQL笔记-最简单的方法来解决找不到mysqld.sock文件的问题
首先,环境:ubuntu 14.04,采用apt-get的方式安装的,手动安装可能路径设置稍有区别. 1.安装MySQL后,用命令行首次启动时发现找不到Mysqld.sock文件,提示: ERROR ...
- mfc显示静态图片最简单的方法
一致都是研究如何调用opencv显示动态图片,但是很多时候在显示图标的时候,都是需要显示静态图片,现在将最简单的方法总结下: 1.添加picture控件 2.添加资源,要求为bmp 3.修改属性 结果 ...
- ECshop设置301最快捷最简单的方法
ECshop设置301最快捷最简单的方法 在 init.php中加入以下代码 if (strtolower($_SERVER['SERVER_NAME'])!='www.fz1688.com') { ...
- git 的简单使用方法
git 的简单使用方法1. 服务器 安装完成2. ssh 中的账号创建完成3. 创建 ssh 账号,会在 ssh 的安装目录下的home 目录里面,多了用户家目录4. 进入该目录 ,创建一个新的文件夹 ...
- JavaScript,一个超级简单的方法判断浏览器的内核前缀
先说明,此处的方法是说超级简单的方法,不是指代码超级少,而是用非常简单的知识点,只要懂得怎么写JavaScript的行内样式就可以判断. 大家应该还记得JavaScript行内样式怎么写吧?(看来我是 ...
- NET MVC1项目升级到MVC2最简单的方法
NET MVC1项目升级到MVC2最简单的方法 把MVC1项目升级到MVC2,最简单的做法如下: 新建MVC2项目 新建一个MVC2项目,把原来MVC1的项目文件全部拷贝到新建MVC2项目目录里,依照 ...
- js 获取当天23点59分59秒 时间戳 (最简单的方法)
js 获取当天23点59分59秒 时间戳 (最简单的方法) new Date(new Date(new Date().toLocaleDateString()).getTime()+24*60*60* ...
- [ASP.NET]更简单的方法:FormsAuthentication登录ReturnUrl使用绝对路径
转自:http://www.cnblogs.com/dudu/p/formsauthentication-returnurl-absoluteuri.html [ASP.NET]更简单的方法:Form ...
随机推荐
- .ds_store是什么文件
.ds_store是什么文件 .DS_Store是Mac OS保存文件夹的自定义属性的隐藏文件,如文件的图标位置或背景色,相当于Windows的desktop.ini. 1,禁止.DS_store生成 ...
- 原生ajax实现方式
http://www.cnblogs.com/rubylouvre/archive/2013/01/08/2851051.html <!DOCTYPE html> <html lan ...
- A电脑能ping 通B电脑,但B电脑无法ping能和访问B
过程: A电脑共享了打印机,B电脑想连接A的打印机,发现拒绝访问,无法登录A电脑 问题: A电脑能ping 通B电脑,但B电脑无法ping能和访问B 原因:A电脑禁用了共享访问 处理:使用一键共享设置 ...
- Reference Counting GC (Part two :Partial Mark & Sweep)
目录 部分标记清除算法 前提 dec_ref_cnt()函数 new_obj()函数 scan_hatch_queue()函数 paint_gray()函数 scan_gray()函数 collect ...
- JQ each 各种标签
类选择器: $("input[class=class1]").each(function(){ alert($(this).val()); }); ID选择器: $("i ...
- 【Uva 1625】Color Length
[Link]: [Description] 给你两个序列,都由大写字母组成; 每次,把两个序列中的一个的开头字母加在字符串的尾端,然后在那个序列中删掉那个开头字母; 最后得到一个字符串; 这个字符串显 ...
- 用Understand阅读 VS2010项目源码
一.查看vs2010项目 打开understand,File-New-Project...-Next-Next [向导第三步,选"Import Visual Sudio project fi ...
- HDU4596 Yet another end of the world 扩展欧几里德性质
这题坑了,我真该吃翔啊,竟然一開始方程设错了并且没有去想连列的问题,我真是坑货,做不出就该又一次理一下嘛.操蛋. 题意:给了N组x,y,z然后 问你是否存在两个或者两个以上的id,是的 id%x的值在 ...
- IsoAlgo3d三维管道软件
IsoAlgo3d三维管道软件 eryar@163.com 1.概述 IsoAlgo3d三维管道软件主要用于将目前国际主流管道设计软件AVEVA PDMS和Intergraph SmartPlatn3 ...
- 关于obj.currentStyle.property、window.getComputedStyle(obj,null).property、obj.style.property的理解
首先是obj,style.property 我一直用这个obj.style.property这个属性来修改内联和外联的obj属性,但是从网上看到了obj.style.property居然只能读取内嵌的 ...