异常：Caused by: java.lang.NoClassDefFoundError: Could not initialize class net.sf.log4jdbc.Properties
参考文章：
使用Log4jdbc-log4j2监听MyBatis中运行的SQL和Connection
使用 log4jdbc格式化输出SQL，maven配置如下：
<dependency>
<groupId>org.bgee.log4jdbc-log4j2</groupId>
<artifactId>log4jdbc-log4j2-jdbc4</artifactId>
<version>1.16</version>
</dependency>
datasouce.xml配置如下：
<!-- DataSource -->
<bean id="dataSourceSpied" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="${db.driver}"></property>
<property name="url" value="${db.url}"></property>
<property name="username" value="${db.username}"></property>
<property name="password" value="${db.password}"></property>
</bean>
<!-- log4jdbc -->
<bean id="dataSource" class="net.sf.log4jdbc.sql.jdbcapi.DataSourceSpy">
<constructor-arg ref="dataSourceSpied" />
</bean>
异常信息：
java.lang.IllegalStateException: Failed to load ApplicationContext
at org.springframework.test.context.CacheAwareContextLoaderDelegate.loadContext(CacheAwareContextLoaderDelegate.java:99) ~[spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.TestContext.getApplicationContext(TestContext.java:122) ~[spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:109) ~[spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:75) ~[spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:312) ~[spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:211) [spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:288) [spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) [junit-4.11.jar:na]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:284) [spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:231) [spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:88) [spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) [junit-4.11.jar:na]
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) [junit-4.11.jar:na]
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) [junit-4.11.jar:na]
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) [junit-4.11.jar:na]
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) [junit-4.11.jar:na]
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) [spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71) [spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.junit.runners.ParentRunner.run(ParentRunner.java:309) [junit-4.11.jar:na]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174) [spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) [.cp/:na]
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) [.cp/:na]
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459) [.cp/:na]
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675) [.cp/:na]
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382) [.cp/:na]
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192) [.cp/:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userDao' defined in file [C:\stsworkspace\git\tqc\tqc-common-dal\target\classes\spring\applicationContext-dal.xml]: Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in URL [file:/C:/stsworkspace/git/tqc/tqc-common-dal/target/classes/spring/datasource.xml]: Cannot resolve reference to bean 'dataSource' while setting bean property 'dataSource'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in URL [file:/C:/stsworkspace/git/tqc/tqc-common-dal/target/classes/spring/datasource.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [net.sf.log4jdbc.sql.jdbcapi.DataSourceSpy]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: Could not initialize class net.sf.log4jdbc.Properties
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:529) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:626) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932) ~[spring-context-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479) ~[spring-context-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:120) ~[spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:60) ~[spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.delegateLoading(AbstractDelegatingSmartContextLoader.java:100) ~[spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.loadContext(AbstractDelegatingSmartContextLoader.java:248) ~[spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.CacheAwareContextLoaderDelegate.loadContextInternal(CacheAwareContextLoaderDelegate.java:64) ~[spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.test.context.CacheAwareContextLoaderDelegate.loadContext(CacheAwareContextLoaderDelegate.java:91) ~[spring-test-3.2.3.RELEASE.jar:3.2.3.RELEASE]
... 25 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in URL [file:/C:/stsworkspace/git/tqc/tqc-common-dal/target/classes/spring/datasource.xml]: Cannot resolve reference to bean 'dataSource' while setting bean property 'dataSource'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in URL [file:/C:/stsworkspace/git/tqc/tqc-common-dal/target/classes/spring/datasource.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [net.sf.log4jdbc.sql.jdbcapi.DataSourceSpy]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: Could not initialize class net.sf.log4jdbc.Properties
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:329) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:107) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1387) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1128) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByName(AbstractAutowireCapableBeanFactory.java:1146) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1096) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
... 39 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in URL [file:/C:/stsworkspace/git/tqc/tqc-common-dal/target/classes/spring/datasource.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [net.sf.log4jdbc.sql.jdbcapi.DataSourceSpy]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: Could not initialize class net.sf.log4jdbc.Properties
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:288) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1045) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:949) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:487) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:323) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
... 51 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [net.sf.log4jdbc.sql.jdbcapi.DataSourceSpy]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: Could not initialize class net.sf.log4jdbc.Properties
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:163) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:121) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:280) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
... 60 common frames omitted
Caused by: java.lang.NoClassDefFoundError: Could not initialize class net.sf.log4jdbc.Properties
at net.sf.log4jdbc.log.SpyLogFactory.getSpyLogDelegator(SpyLogFactory.java:69) ~[log4jdbc-log4j2-jdbc4-1.16.jar:na]
at net.sf.log4jdbc.sql.jdbcapi.DataSourceSpy.<init>(DataSourceSpy.java:90) ~[log4jdbc-log4j2-jdbc4-1.16.jar:na]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_11]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_11]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_11]
at java.lang.reflect.Constructor.newInstance(Constructor.java:408) ~[na:1.8.0_11]
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:148) ~[spring-beans-3.2.3.RELEASE.jar:3.2.3.RELEASE]
... 62 common frames omitted
16:44:15.402 [main] DEBUG o.s.t.c.s.DirtiesContextTestExecutionListener - After test class: context [[TestContext@8a9f61 testClass = TestUserDao, testInstance = [null], testMethod = [null], testException = [null], mergedContextConfiguration = [MergedContextConfiguration@16905e testClass = TestUserDao, locations = '{classpath*:/spring/applicationContext*.xml, classpath*:/spring/datasource.xml}', classes = '{}', contextInitializerClasses = '[]', activeProfiles = '{}', contextLoader = 'org.springframework.test.context.support.DelegatingSmartContextLoader', parent = [null]]]], dirtiesContext [false].
产生原因：
我的日志环境使用的是slf4j，log4jdbc-log4j2默认只支持log4j2，如果想要支持slf4j，则需要增加如下配置：
Configure log4jdbc-log4j2 options log4jdbc-log4j2 can be configured in the exact same way than log4jdbc (see below). Please note two changes as compared to log4jdbc: log4jdbc.spylogdelegator.name: this is a new option, allowing to provide the qualified class name of the logger to use. Notably, if you want to use the SLF4J logger rather than Log4j 2, you must set this option to the valuenet.sf.log4jdbc.log.slf4j.Slf4jSpyLogDelegator.
解决方案：
在classpath的jdbc.properties中增加如下配置：
#jdbc settings
#db.driver=com.mysql.jdbc.Driver
#db.url=jdbc:mysql://127.0.0.1:3306/tqc
db.driver=net.sf.log4jdbc.sql.jdbcapi.DriverSpy
db.url=jdbc:log4jdbc:mysql://127.0.0.1:3306/tqc
db.username=aaa
db.password=aaa
log4jdbc.log4j2.properties中增加如下配置
dbc.spylogdelegator.name=net.sf.log4jdbc.log.slf4j.Slf4jSpyLogDelegator
log4jdbc.debug.stack.prefix=
log4jdbc.sqltiming.warn.threshold=
log4jdbc.sqltiming.error.threshold=
log4jdbc.dump.booleanastruefalse=
log4jdbc.dump.sql.maxlinelength=
log4jdbc.dump.fulldebugstacktrace=
log4jdbc.statement.warn=
log4jdbc.dump.sql.select=
log4jdbc.dump.sql.insert=
log4jdbc.dump.sql.update=
log4jdbc.dump.sql.delete=
log4jdbc.dump.sql.create=
log4jdbc.dump.sql.addsemicolon=
log4jdbc.auto.load.popular.drivers=
log4jdbc.trim.sql=
log4jdbc.trim.sql.extrablanklines=
log4jdbc.suppress.generated.keys.exception=
log4jdbc.drivers=
异常：Caused by: java.lang.NoClassDefFoundError: Could not initialize class net.sf.log4jdbc.Properties的更多相关文章
- 异常-----java.lang.NoClassDefFoundError: Could not initialize class net.sf.cglib.core.KeyFactory
SSH 类库问题 java.lang.NoClassDefFoundError: Could not initialize class net.sf.cglib.proxy.Enhancer2009- ...
- java.lang.NoClassDefFoundError: Could not initialize class net.sf.json.util.JSONUtils
页面报错: root: java.lang.NoClassDefFoundError: Could not initialize class net.sf.json.util.JSONUtils 出错 ...
- 类找不到异常 Caused by: java.lang.NoClassDefFoundError
错误原因:在部署应用的时候,服务器报错,Caused by: java.lang.ClassNotFoundException: org.quartz.impl.JobDetailImpl,某个类找不 ...
- Caused by: java.lang.NoClassDefFoundError: Could not initialize class org.elasticsearch.threadpool.ThreadPool
springboot中遇到的, 将guava添加到项目中即可.(当时添加的是guava 18)
- Java 上传文件到 SFTP 抛异常 java.lang.NoClassDefFoundError: Could not initialize class sun.security.ec.SunEC 的解决办法
最近从 Op 那里报来一个问题,说是SFTP上传文件不成功.拿到的 Exception 如下: Caused by: java.lang.NoClassDefFoundError: Could not ...
- java.lang.NoClassDefFoundError: Could not initialize class异常处理
借鉴:http://blog.csdn.net/sleepdancer/article/details/9207425 static { InputStream in = XXX.class.getR ...
- 【转】Caused by: java.lang.NoClassDefFoundError: android.support.v7.gridlayout.R$dimen 异常解决方法
在使用gridlayout中遇到 Caused by: java.lang.NoClassDefFoundError: android.support.v7.gridlayout.R$dimen 问题 ...
- 异常：Caused by: java.lang.NoClassDefFoundError: org/springframework/web/context/WebApplicationContext
说明项目没有加载jar包 异常:Caused by: java.lang.NoClassDefFoundError: org/springframework/web/context/WebApplic ...
- 1.spring异常：Caused by: java.lang.NoClassDefFoundError: org/aopalliance/intercept/MethodInterceptor
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springfr ...
随机推荐
- c/c++常用代码--清空目录
#pragma once #include <io.h>#include <stdio.h>#include <string>#include <direct ...
- Notes of the scrum meeting(11/1)
meeting time:9:00~10:30p.m.,November 1st,2013 meeting place:20号公寓楼前 attendees: 顾育豪 ...
- android 中设置HttpURLConnection 超时并判断是否超时
设置超时: URL url1 = new URL(url); HttpURLConnection conn = (HttpURLConnection) url1.openConnection(); c ...
- Xcode Provisioning 路径
~/Library/MobileDevice/Provisioning Profiles
- BZOJ 1083: [SCOI2005]繁忙的都市 裸的最小生成树
题目链接: http://www.lydsy.com/JudgeOnline/problem.php?id=1083 代码: #include<iostream> #include< ...
- git撤销删除
问题描述: 使用git时本地文件删除了,提交至github,希望撤销修改,找回源文件 问题解决: (1)查看git log,查看日志信息 注: 使用 git log 可以查看提交的日志 ...
- Spring3+hibernate4+struts2整合的 过程中发生如下错误
严重: Error configuring application listener of class org.springframework.web.context.ContextLoaderLis ...
- Unit Test Generator
- uva 11986
假设有n只老鼠 每只老鼠有两种状态 死或活 则n只老鼠有 2^n方种状态 所以n只老鼠可以确定2^n只瓶子 #include <cstdio> #include <cstdlib&g ...
- Xamarin.Android 入门之：Android的生命周期
一.前言 活动是Android应用程序的基本构建块,他们可以在许多不同的状态存在.当你把一个Android程序置于后台,过一段时间再打开发现之前的数据还存在. 二.活动状态 下面的图表说明了一个活动可 ...