Warning: Cannot update during an existing state transition (such as within `render`). Render 报错

react事件绑定的三种常见方式以及解决Cannot update during an existing state transition (such as within `render`). Render methods should be a pure function of props and state问题思路

在 React 组件中,每个方法的上下文都会指向该组件的实例,即自动绑定 this 为当前组件. 而且 React 还会对这种引用进行缓存,以达到 CPU 和内存的优化.在使用 ES6 classes 或者纯函数时,这种自动绑定就不复存在了,我们需要手动实现 this 的绑定. 1.bind方法进行绑定,这个方法可以帮助我们绑定事件处理器内的 this ,并可以向事件处理器中传递参数,如下图清晰明了: bind方法绑定 2.箭头函数进行绑定,箭头函数不仅是函数的“语法糖”,它还自动绑定了定义…

Oracle存储过程执行update语句不报错不生效问题

转载链接:http://lin49940.iteye.com/blog/466626 今天一个同事写oracle 的存储过程遇到了一个问题, 他在里面update 操作不能完成更新的操作, 但是又不会报错. 如一个表 A(id, code, name, type) 在存储过程中的更新操作的语句: update A x set x.type = 变量A where x.code = 变量B; 变量A 和变量B 都定义好了, 并且都成功赋值了. 这是一个很简单的更新语句, 简单到一开始对为什么发生…

ALTER添加列后，立即UPDATE该列会报错

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异常堆栈如下: 2015-11-24 16:49:11,495 ERROR org.apache.hive.service.cli.operation.Operation: Error running hive query: org.apache.hive.service.cli.HiveSQLException: Illegal Operation state transition from CLOSED to ERROR at org.apache.hive.service.c…

论文阅读：Flow-level State Transition as a New Switch Primitive for SDN

Name of article:Flow-level State Transition as a New Switch Primitive for SDN Origin of the article:Moshref M , Bhargava A , Gupta A , et al. [ACM Press the 2014 ACM conference - Chicago, Illinois, USA (2014.08.17-2014.08.22)] Proceedings of the 2014…

React报错：Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix,

今天在开发时报了以下错误,记录一下我们不能在组件销毁后设置state,防止出现内存泄漏的情况出现原因直接告诉你了,组件都被销毁了,还设置个锤子的state啊解决方案: 利用生命周期钩子函数:componentWillUnmount 将报错的地方移入此钩子里进行处理 componentWillUnmount(){//处理逻辑 }…

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ecstore在MySQL5.7下维护报错WARNING:512 @ ALTER IGNORE TABLE

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mac brew update 报错

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React篇-报错信息：warning: Can't call setState (or forceUpdate) on an unmounted component.

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yum -y update 报错：GPG key retrieval failed: [Errno 14] Could not open/read file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

用的是centos6.5的镜像,yum源太老了,修改了之后想更新一下: yum -y update 执行报错: warning: rpmts_HdrFromFdno: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5 GPG key retrieval failed: [Errno 14] Could not o…

(TODO:)下载图片,报错:warning: could not load any Objective-C class information from the dyld shared cache. This will significantly reduce the quality of type information available.

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关于mvc5+EF里面的db.Entry(model).State = EntityState.Modified报错问题

最近在使用mvc5+EF的的时候用到了这句话 db.Entry(model).State = EntityState.Modified 看上去很简单的修改数据,但是一直报错,说是key已经存在,不能修改. 搞了很久,突发奇想的把前面的代码 var approvalModel = CurrentUser.ApplicationForms.SingleOrDefault(t => t.ID == id).Approval; if(approvalModel!=null){ db.Entry(mode…

终端ssh登录mac用shell打包ipa报错：replacing existing signature

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【maven 报错】maven项目执行maven install时报错Error assembling WAR: webxml attribute is required (or pre-existing WEB-INF/web.xml if executing in update mode)

在使用maven新建的web项目中,执行执行如上的这两个操作,报错: [ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.5.1:compile (default-compile) on project bioligyInfo: Fatal error compiling: tools.jar not found: C:\Program Files\Java\jre1.8.0_73\..…

Maven-010-maven 编译报错：Failure to ... in ... was cached in the local repository, resolution will not be reattempted until the update interval of nexus has elapsed or updates are forced.

今晚在编译 maven 项目的时候,命令行报错,出现 Failure to ... in ... 类似错误,详细的错误信息如下所示: [INFO] ------------------------------------------------------------------------ [INFO] Building arrow [INFO] ------------------------------------------------------------------------ […

【Xamarin报错】libpng warning : iCCP: Not recognizing known sRGB profile that has been edited

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【maven 报错】maven项目update之后报错One or more constraints have not been satisfied.

在右键项目Update Project之后报错:One or more constraints have not been satisfied.Spring 4.1 requires Java 1.6 or newer. 解决问题: The solution is I have to goto to the ".settings" folder which is at the project location and deleted "org.eclipse.wst.comm…

mysql执行update报错1175解决方法

mysql执行update报错 update library set status=true where 1=1 Error Code: 1175. You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column To disable safe mode, toggle the option in Preferences -> SQL Queries and…

Sybase ASE报错：server Error: 8242, Severity: 16, State: 1

昨天上午,同事反映某系统在执行存储过程的过程中报错了,报错的信息异常如下: 05:00000:00009:2014/06/09 15:45:30.34 server Error: 8242, Severity: 16, State: 1 05:00000:00009:2014/06/09 15:45:30.34 server The table 'USER_FILES' in database 'PRODB' is bound to metadata cache memory. Unbind t…

sqlplus 连接数据库报错SP2-0642: SQL*Plus internal error state 2130, context 0:0:0

sqlplus 连接数据库报错SP2-0642: SQL*Plus internal error state 2130, context 0:0:0 问题描述: 使用sqlplus客户端登录数据库,报错SP2-0642,而使用其它方式plsql或者tnsnames等方式连接数据库均没有问题 [oracle@test2 ~]$ sqlplus adt/passwd@192.168.112.235:1521/srv_test1 SQL*Plus: Release 10.2.0.1.0 - Produ…

解决Undefined symbols for architecture x86_64: 报错和 ld: warning: ld: warning: ignoring file警告

出现这种错误的情况: 用iphone5模拟器编译程序正常, 用iphone5s以上的模拟器编译出现Undefined symbols for architecture x86_64: 报错和 ld: warning: ld: warning: ignoring file警告, 用真机编译正常... 网上找了很多解决方法都没办法解决..都是说更改bulid setting的一些相关设置..然后都木有什么卵用... 这里附上我的解决方法..其实也不是很麻烦...(我没有更改bulid settin…

Maven项目下update maven后Eclipse报错：java.lang.ClassNotFoundException: ContextLoaderL

Maven项目下update maven后Eclipse报错:java.lang.ClassNotFoundException: ContextLoaderL 严重: Error configuring application listener of class org.springframework.web.context.ContextLoaderListener java.lang.ClassNotFoundException: org.springframework.web.co…

支付宝支付php的demo或sdk报错 Warning: openssl_sign() [function.openssl-sign]: Unknown signature algorithm. in

最近在做支付宝支付,在本地测试一切正常,上传到服务器就遇到报错: Warning: openssl_sign() [function.openssl-sign]: Unknown signature algorithm. in 后来查了查,是我的服务器上PHP环境支持openssl_sign()但却不支持 OPENSSL_ALGO_SHA256这样的参数,问了一下大佬,才发现这个参数是在php5.4.8以上版本才支持,低版本的是使用的SHA256,于是乎试了一下,搞定! 报错原因是支付宝的dem…