使用zxing时找不到类 [英] Class not found when using zxing

问题描述

所以，我开发一个应用程序，它可以扫描QR codeS。我下载了ZXing库，建造它采用Apache Ant来获得core.jar添加，把它放在我的项目文件夹，并添加它作为一个罐子到构建路径。没有当我尝试执行以下操作：

So i'm developing an app that can scan QR codes. I downloaded the ZXing library, built it using apache ant to get the core.jar, put it in my project folder and added it as a jar to the build path. No when i try do the following:

Intent intent = new Intent("com.google.zxing.client.android.SCAN");
intent.putExtra("SCAN_MODE", "QR_CODE_MODE"); 
startActivityForResult(intent, 0);

我收到以下错误：

I get the following error:

08-14 18:52:01.191: E/AndroidRuntime(617): FATAL EXCEPTION: main
08-14 18:52:01.191: E/AndroidRuntime(617): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.android.Wowser/com.google.zxing.client.android.CaptureActivity}: java.lang.ClassNotFoundException: com.google.zxing.client.android.CaptureActivity in loader dalvik.system.PathClassLoader[/data/app/com.android.Wowser-1.apk]
08-14 18:52:01.191: E/AndroidRuntime(617):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1569)
08-14 18:52:01.191: E/AndroidRuntime(617):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
08-14 18:52:01.191: E/AndroidRuntime(617):  at android.app.ActivityThread.access$1500(ActivityThread.java:117)
08-14 18:52:01.191: E/AndroidRuntime(617):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
08-14 18:52:01.191: E/AndroidRuntime(617):  at android.os.Handler.dispatchMessage(Handler.java:99)
08-14 18:52:01.191: E/AndroidRuntime(617):  at android.os.Looper.loop(Looper.java:123)
08-14 18:52:01.191: E/AndroidRuntime(617):  at android.app.ActivityThread.main(ActivityThread.java:3683)
08-14 18:52:01.191: E/AndroidRuntime(617):  at java.lang.reflect.Method.invokeNative(Native Method)
08-14 18:52:01.191: E/AndroidRuntime(617):  at java.lang.reflect.Method.invoke(Method.java:507)
08-14 18:52:01.191: E/AndroidRuntime(617):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
08-14 18:52:01.191: E/AndroidRuntime(617):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
08-14 18:52:01.191: E/AndroidRuntime(617):  at dalvik.system.NativeStart.main(Native Method)
08-14 18:52:01.191: E/AndroidRuntime(617): Caused by: java.lang.ClassNotFoundException: com.google.zxing.client.android.CaptureActivity in loader dalvik.system.PathClassLoader[/data/app/com.android.Wowser-1.apk]
08-14 18:52:01.191: E/AndroidRuntime(617):  at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
08-14 18:52:01.191: E/AndroidRuntime(617):  at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
08-14 18:52:01.191: E/AndroidRuntime(617):  at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
08-14 18:52:01.191: E/AndroidRuntime(617):  at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
08-14 18:52:01.191: E/AndroidRuntime(617):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1561)
08-14 18:52:01.191: E/AndroidRuntime(617):  ... 11 more

<?xml version="1.0" encoding="utf-8"?>

<uses-sdk android:minSdkVersion="10" />

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.CAMERA"/>

<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" >
    <activity
        android:name="com.android.Wowser.DealsActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name="com.google.zxing.client.android.CaptureActivity"
        android:configChanges="orientation|keyboardHidden"
        android:screenOrientation="landscape"
        android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
        android:windowSoftInputMode="stateAlwaysHidden" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
        <intent-filter>
            <action android:name="com.google.zxing.client.android.SCAN" />

            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </activity>
    <activity android:name=".Register" />
    <activity android:name=".SignIn" />
    <activity android:name=".Options" />
    <activity android:name=".Scan" />
</application>

谁能告诉我如何建立Zxing正确地使用它或者我可能会错误？任何帮助是极大的AP preciated。

Can anyone tell me how i set up the Zxing to use it properly or where i might be going wrong? Any help is greatly appreciated.

推荐答案

有只有三个原因，你永远不会得到这个错误：

There are only three reasons you will ever get this error:

1. 类真的不存在。如果您是从官方的例子使用code和得到这个，请确保您有库的最新版本
2. 您还没有添加罐子构建路径。要解决此问题，右键单击Eclipse中的罐子，也构建路径►添加到构建路径。
3. 您的罐子是不是在/ libs文件夹中。这种情况发生时，你已经添加了罐子到构建路径，但新版本的ADT需要它是在/库。把它放在那里，并重新添加到构建路径。

这篇关于使用zxing时找不到类的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！