two
two desk控制完电脑后如何取消控制?
desk控制完电脑后如何取消控制?
1.首先,按住快捷键:win R,调出“运行”。
2.接着,在“运行”里面输入“msconfig”。
3.然后,点击“确定”。
4.然后,找到“服务”。
5.接着,将所有服务“全部禁止”。
6.然后,选择“应用”和“确定”
苹果应用商店的更新是增量更新吗?
首先回答问题之前我想问一下您是开发人员还是普通用户。如果是普通用户,我很兴奋,一个普通用户能想到这个并提出这个问题,真的很了不起。对,很了不起!very Good!
如果你是普通用户,我直接在这里简短回答你一下:苹果在iOS7之后就已经支持增量更新了。但是,回到你的问题,苹果应用商店的更新是增量更新吗?回答是:有的是,有的不是。苹果是支持增量更新,但是有的开发者他么有想去使用这个功能,或者因为技术原因,放弃了这个功能,所以某些app没有增量更新这个功能,你每次下载还是得全部重下载。而一些优化做的比较好的app是支持增量更新的,例如某宝之类的。
如果你是程序狗,下拉2行,不影响其他用户阅读,咱们去深水区探讨下,我抛砖引玉,也希望大神来接着给点意见。
关于iOS应用的增量更新,iOS7.0以后就已经支持,具体参见文档
Q: How can I reduce the downloaded size of my app update for users that already have the previous version installed?
A: This document is specific to app updates. See Technical QampA QA1795: Reducing the size of my App for a collection of techniques to reduce the size of an app when it is downloaded and installed for the first time.
Starting with iOS 6, the app store will automatically produce an update package for all new versions of apps submitted to the store. When generating the update package, the app store compares one or more prior versions of your app to the new version and creates an optimized package for each that contains only the content that has changed between versions of your app, excluding any content that did not change. This comparison looks at everything in the application bundle, including the application executable, nibs, localizations, image files, video files, audio files, text files, and files containing data in a custom format.
Note: The ability to create update packages is not currently available to developers who do not distribute their apps through the app store, such as those distributing enterprise apps.
When used optimally, an update package is significantly smaller to download than the full package of the app and the update will install more quickly. Also, in many cases, this mechanism allows updates to large apps to be downloadable over cellular networks where app downloads are subject to a size limit.
In addition to new content, the update package contains instructions on how to transform the prior version of the app into the new version of the app. New files will be added, modified files will be replaced with their updated counterpart, and deleted files will be removed as part of this transformation. As far as the developer and user are concerned, this process is entirely transparent and the resulting updated app will be indistinguishable from a full download of the corresponding updated version of their app.
To optimize the size of your app updates, you should consider two tips:
Do not make unnecessary modifications to files. Compare the contents of the prior and new versions of your app with or another directory comparison tool and verify that youve only changed what you expect within your app bundle.
Content that you expect to change in an update should be stored in separate files from content that you dont expect to change. This reduces the size of the update package and increases its install speed.
For devices running iOS 6.x and iOS 7.0, the update package will include any file, in its entirety, that has changed in the new version of the app. For example, if you have a 10 MB file in your app and only change 1 KB of content within that file in the new version of the app, the update package for that new version will contain the full 10 MB file.
For devices running iOS 7.1 and later, the update package may include only the differences between the old and new versions of a changed file instead of the full file. This may significantly reduce the size of the update package in the case where only a small part of a large file changes, but will increase the updates installation time on the device. For this reason, the two tips above are still important even for updates on iOS 7.1 and later. Minimizing changed content and localizing it to many smaller files instead of one larger monolithic file will reduce the download size in all cases and will speed up installation on devices running iOS 7.1 and later.
7.1以后就已经自动进行增量更新了,但是有很多开发者发现自己的应用每次更新还是下载了全部大小,并不是文档里写的只下载修改的大小,当然有的是文档所写的所有文件都进行了无必要的修改。大部分是因为对bitcode的修改,直接设置为disable,所以苹果不能自动就行增量更新。这里就不解释为什么很多人为什么要将bitcode设置为disable了,大部分从xcode7过来的都深有体会。只说一下为什么苹果为什么从xcode7开始默认打开bitcode?为什么苹果默认要求watchOS和tvOS的App要上传bitcode? 因为把bitcode上传到他自己的中心服务器后,他可以为目标安装App的设备进行优化二进制,减小安装包的下载大小,当然iOS开发者也可以上传多个版本而不是打包到单个包里,但是这样会占用更多的存储空间. 最重要的是允许苹果可以在后台服务器对应用程序进行签名,而不用导出任何密钥到终端开发者那。
这是正常的增量更新方法了。还有“不正常的”热更新。这个也是那些每次打开app就进行远程检查版本是否需要跟新的app的套路,比如那农药啊。我个人之前也喜欢捣鼓这个热更新。因为要睡觉了,先引用下别人写的,有时间再来优化。
iOS主要是使用JSPatch来实现热补丁修复,在项目中引入JSPathc,然后在发现bug时下发JS脚本补丁,替换原生方法,以此实现无需更新APP即时修复bug。
主要实现流程:当客户端出现bug时,iOS开发人员需要开发一段JS脚本用于修复bug,脚本开发完成后,服务端开发人员根据iOS开发人员提供的JS脚本部进行一定的安全策略部署服务端脚本,iOS客户端通过脚本版本检测接口,判断是否需要下载JS脚本,下载脚本成功后,进行加载,运行,进而修复APP的bug。
其中,客户端与服务端在获取JS脚本时会进行安全校验,防止过程中被攻击替换代码,安全校验的简单流程:a.服务端对JS脚本文件生成一个MD5(文件的唯一标识)值并加密——b.将加密的MD5值与JS脚本传给客户端——c.客户端对拿到的脚本文件计算MD5值,且对加密的MD5值进行解密——d.客户端对比计算出的MD5值与解密后的MD5值——e.两个MD5数值相等则通过校验。
热补丁技术不仅可以用来修复bug打补丁,还可以在线更新代码添加新需求哦!
增量更新技术 定义
增量更新是指在进行更新操作时,只更新需要改变的地方,不需要更新或者已经更新过的地方则不会重复更新。也就是,只将App中有发生改变的部分发送给用户,而不是每次都重新下载一个完整的安装包。
原理
生成差异包。将 App 的最新安装包(V2)与历史发布版本的安装包(V1)进行差分对比,得到一个差异包(V2-V1)。下发差异包。当某个老版本(V1)的 App 开始检查更新的时候,需要将自己当前的版本信息发送给服务端,然后服务端判断后,选择对应的差异包(V2-V1)下发。合成新包。校验完整性。校验当前历史包的Hash值以及差异包的Hash(哈希值是一段数据唯一的数值表示形式)值,合成新包后,也要校验新包的Hash值,只有这三个Hash值都与预期匹配,才可以确认新包是完整的。增量更新的注意点:
增量更新是以两个应用版本之间的差异来生成补丁的,无法保证用户每次及时升级到最新,所以必须对所发布的每一个版本都和最新的版本作差分,以使所有版本的用户都可以差分升级,这样操作较为繁琐,不过可以通过脚本批量生成。增量更新成功的前提是,用户手机端必须有能够被拷贝出来且与服务器用于差分的版本一致的APK文件,这样就会造成一些情况,例如,系统内置的APK无法获取到,则无法进行增量更新。
下面有请大神继续补充,我来吃个瓜!