即时通讯尝试在我正在构建的应用程序中使用android目录选择器 . 这是net.bgreco.DirectoryPicker . 我的应用程序称为WebDownloader . 它似乎运行良好 . 并且我能够自己启动目录选择器应用程序但是当我尝试将其作为活动从我的主要活动启动时我在帖子 Headers 中提到错误 .

07-15 21:36:58.740 31945-31945 / com.example.zacharymcdaniel.webdownloader E / AndroidRuntime:FATAL EXCEPTION:main进程:com.example.zacharymcdaniel.webdownloader,PID:31945 java.lang.NoClassDefFoundError:失败的解析:Lnet / bgreco / R $布局;在net.bgreco.DirectoryPicker.onCreate(DirectoryPicker.java:70)的android.app.A活动中的android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1213)的android.app.Activity.performCreate(Activity.java:6980) . Activity.Thread.performLaunchActivity(ActivityThread.java:2770)位于android.app.ActivityThread的Android.app.A活动时,活动强化(ActivityThread.java:2892)android.app.ActivityThread.-wrap11(未知来源:0)$ H.handleMessage (ActivityThread.java:1593)android.app.Handler.dispatchMessage(Handler.java:105)位于android.app.ActivityThread.main的android.os.Looper.loop(Looper.java:164)处(ActivityThread.java: 6540)位于com.android.internal.os.ZygoteInit.main的com.android.internal.os.Zygote $ MethodAndArgsCaller.run(Zygote.java:240)的java.lang.reflect.Method.invoke(Native Method)( ZygoteInit.java:767)引起:java.lang.ClassNotFoundException:路径上没有找到类“net.bgreco.R $ layout”:DexPathList [[zip file“/data/app/com.example.zacharymcdaniel.webdownloade r-y2pFpZ6io92LNAzJNpMhyw == / base.apk“,zip文件”/data/app/com.example.zacharymcdaniel.webdownloader-y2pFpZ6io92LNAzJNpMhyw==/split_lib_dependencies_apk.apk“,zip文件”/data/app/com.example.zacharymcdaniel . webdownloader-y2pFpZ6io92LNAzJNpMhyw == / split_lib_slice_0_apk.apk“,zip文件”/data/app/com.example.zacharymcdaniel.webdownloader-y2pFp6io92LNAzJNpMhyw==/split_lib_slice_1_apk.apk“,zip文件”/data/app/com.example.zacharymcdaniel . webdownloader-y2pFpZ6io92LNAzJNpMhyw == / split_lib_slice_2_apk.apk“,zip文件”/data/app/com.example.zacharymcdaniel.webdownloader-y2pFp6io92LNAzJNpMhyw==/split_lib_slice_3_apk.apk“,zip文件”/data/app/com.example.zacharymcdaniel . webdownloader-y2pFpZ6io92LNAzJNpMhyw == / split_lib_slice_4_apk.apk“,zip文件”/data/app/com.example.zacharymcdaniel.webdownloader-y2pFpZ6io92LNAzJNpMhyw==/split_lib_slice_5_apk.apk“,zip文件”/data/app/com.example.zacharymcdaniel . webdownloader-y2pFpZ6io92LNAzJNpMhyw == / split_lib_slice_6_apk.apk“,zip file”/data/app/com.example.zacha rymcdaniel.webdownloader-y2pFpZ6io92LNAzJNpMhyw == / split_lib_slice_7_apk.apk“,zip文件”/data/app/com.example.zacharymcdaniel.webdownloader-y2pFp6io92LNAzJNpMhyw==/split_lib_slice_8_apk.apk“,zip文件”/data/app/com.example . zacharymcdaniel.webdownloader-y2pFpZ6io92LNAzJNpMhyw == / split_lib_slice_9_apk.apk“],nativeLibraryDirectories = [/ data / app / com.example.zacharymcdaniel.webdownloader-y2pFpZ6io92LNAzJNpMhyw == / lib / x86,/ system / lib,/ system / vendor / lib] ] atdalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:93)at java.lang.ClassLoader.loadClass(ClassLoader.java:379)at java.lang.ClassLoader.loadClass(ClassLoader.java:312)at net.bgreco .DirectoryPicker.onCreate(DirectoryPicker.java:70)位于android.app.A活动中的android.app.Asetrumentation.Ap响应时,Android.app.A活动中的android.app.Asetrumentation.callActivityOnCreate(Instrumentation.java:1213)上的android.app.Activity.performCreate(Activity.java:6980) ActivityThread.java:2770)在android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892)at at android.app.ActivityThread.-wrap11(未知来源:0)在android.app.ActivityThread $ H.handleMessage(ActivityThread.java:1593)android.os.Handler.dispatchMessage(Handler.java:105)android.os位于android.app.ActivityThread.main(ActivityThread.java:6540)的.Looper.loop(Looper.java:1640)位于com.android.internal.os.Zygote的java.lang.reflect.Method.invoke(Native Method) $ MethodAndArgsCaller.run(Zygote.java:240)at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

WebDownloader和DirectoryPicker都是我的android项目结构中的顶级文件夹 . 这是我的应用程序gradle

apply plugin: 'com.android.application'

android {
compileSdkVersion 25
buildToolsVersion "25.0.3"
defaultConfig {
    applicationId "com.example.zacharymcdaniel.webdownloader"
    minSdkVersion 19
    targetSdkVersion 25
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
}

dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:25.3.1'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
testCompile 'junit:junit:4.12'
compile 'io.reactivex:rxjava:1.1.6'
compile 'io.reactivex:rxandroid:1.2.1'
compile files('libs/directorypicker.jar')
}

和我的清单:

`<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.zacharymcdaniel.webdownloader">

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name="net.bgreco.DirectoryPicker"/>
</application>

</manifest>`

和DirectoryPicker的清单:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="net.bgreco"
  android:versionCode="2"
  android:versionName="1.0.1">

<application android:icon="@drawable/icon" android:label="@string/app_name">
    <activity android:name=".DirectoryPicker"
              android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.LAUNCHER"/>
        </intent-filter>
    </activity>

</application>
</manifest>

我正在努力使它能够使用Intent和startActivityForResult启动目录选择器 . 请帮我找出问题所在 .