关于android-support-v4.jar包的错误 _android

高斋晓开卷，独共圣人语。这篇文章主要讲述关于android-support-v4.jar包的错误相关的知识，希望能为你提供帮助。
1.加入android-support-v4 误 java.lang.ClassNotFoundException: android.support.v4.view.ViewPager in loade
问题：在使用ViewPager加入android-support-v4.jar后提演示样例如以下错

11-15 21:01:21.725: E/AndroidRuntime(32431): Caused by: java.lang.ClassNotFoundException: android.support.v4.view.ViewPager in loader dalvik.system.PathClassLoader[/system/framework/com.google.android.maps.jar:/mnt/asec/com.trinea.android.demo-2/pkg.apk]

完整错误为
我是通过项目 -> 属性 -> Java Build Path -> Add External JARs加入了android-support-v4.jar包的。解决仅仅须要项目 -> 属性 -> Java Build Path -> Remove该jar，直接将jar包拷贝到项目的libs文件夹下就可以。由于项目libs下的jar包会自己主动导入项目。不须要手动导入。自己主动导入的包存在在 Android Private文件夹下。

15 21:01:21.725: E/AndroidRuntime(32431): FATAL EXCEPTION: main -15 21:01:21.725: E/AndroidRuntime(32431): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.trinea.android.demo/com.trinea.android.demo.ViewPagerDemo}: android.view.InflateException: Binary XML file line #7: Error inflating class android.support.v4.view.ViewPager -15 21:01:21.725: E/AndroidRuntime(32431):at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1664) -15 21:01:21.725: E/AndroidRuntime(32431):at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1680) -15 21:01:21.725: E/AndroidRuntime(32431):at android.app.ActivityThread.access$1500(ActivityThread.java:117) -15 21:01:21.725: E/AndroidRuntime(32431):at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) -15 21:01:21.725: E/AndroidRuntime(32431):at android.os.Handler.dispatchMessage(Handler.java:99) -15 21:01:21.725: E/AndroidRuntime(32431):at android.os.Looper.loop(Looper.java:130) -15 21:01:21.725: E/AndroidRuntime(32431):at android.app.ActivityThread.main(ActivityThread.java:3703) -15 21:01:21.725: E/AndroidRuntime(32431):at java.lang.reflect.Method.invokeNative(Native Method) -15 21:01:21.725: E/AndroidRuntime(32431):at java.lang.reflect.Method.invoke(Method.java:507) -15 21:01:21.725: E/AndroidRuntime(32431):at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841) -15 21:01:21.725: E/AndroidRuntime(32431):at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599) -15 21:01:21.725: E/AndroidRuntime(32431):at dalvik.system.NativeStart.main(Native Method) -15 21:01:21.725: E/AndroidRuntime(32431): Caused by: android.view.InflateException: Binary XML file line #7: Error inflating class android.support.v4.view.ViewPager -15 21:01:21.725: E/AndroidRuntime(32431):at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:581) -15 21:01:21.725: E/AndroidRuntime(32431):at android.view.LayoutInflater.rInflate(LayoutInflater.java:623) -15 21:01:21.725: E/AndroidRuntime(32431):at android.view.LayoutInflater.inflate(LayoutInflater.java:408) -15 21:01:21.725: E/AndroidRuntime(32431):at android.view.LayoutInflater.inflate(LayoutInflater.java:320) -15 21:01:21.725: E/AndroidRuntime(32431):at android.view.LayoutInflater.inflate(LayoutInflater.java:276) -15 21:01:21.725: E/AndroidRuntime(32431):at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:212) -15 21:01:21.725: E/AndroidRuntime(32431):at android.app.Activity.setContentView(Activity.java:1681) -15 21:01:21.725: E/AndroidRuntime(32431):at com.trinea.android.demo.ViewPagerDemo.onCreate(ViewPagerDemo.java:28) -15 21:01:21.725: E/AndroidRuntime(32431):at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) -15 21:01:21.725: E/AndroidRuntime(32431):at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1628) -15 21:01:21.725: E/AndroidRuntime(32431):... 11 more -15 21:01:21.725: E/AndroidRuntime(32431): Caused by: java.lang.ClassNotFoundException: android.support.v4.view.ViewPager in loader dalvik.system.PathClassLoader[/system/framework/com.google.android.maps.jar:/mnt/asec/com.trinea.android.demo-2/pkg.apk] -15 21:01:21.725: E/AndroidRuntime(32431):at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240) -15 21:01:21.725: E/AndroidRuntime(32431):at java.lang.ClassLoader.loadClass(ClassLoader.java:551) -15 21:01:21.725: E/AndroidRuntime(32431):at java.lang.ClassLoader.loadClass(ClassLoader.java:511) -15 21:01:21.725: E/AndroidRuntime(32431):at android.view.LayoutInflater.createView(LayoutInflater.java:471) -15 21:01:21.725: E/AndroidRuntime(32431):at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:570)

【关于android-support-v4.jar包的错误】2.java.lang.ClassNotFoundException: Didn‘t find class "android.support.v4.view.ViewPager" on path: /data/app/XXX.apk
解决方式：把第三方的包(android-support-v4.jar)放在项目文件夹下的libs里,右键项目选择：Build Path -> use as source folder,就OK了。
然后Add jar 将android-support-v4.jar加入上来就可以。

总结：遇到这样的问题，解决方式就是须要将jar包导入到项目文件夹中，能够放在 Android private 中，这个是adt在载入项目的时候自己主动载入进来的，也能够直接自己Add jar加入进来，注意包的反复问题。这一块不easy说清楚，自己按情况进行解决。

补充：其它能够使用的方法
1.在项目的properties中的Java Build Path里将Order and Export里的android-support-v4.jar勾选上。

2.最简单的在项目上右键Android Tools选FIx Project Properties。