解析失败：Lcom/abhi/barcode/frag/libv2/R$string
Failed resolution of: Lcom/abhi/barcode/frag/libv2/R$string
我正在尝试启动一个 Activity，里面有一个正在执行 QR 扫描的片段，
我正在为此使用这个库>
https://code.google.com/archive/p/barcodefraglibv2/
我按照说明做所有事情，但是当我 运行 应用程序时，它会抛出一个异常：
Failed resolution of: Lcom/abhi/barcode/frag/libv2/R$string
我做错了什么？
这是我的主要内容Activity：
package apps.radwin.zxingprojectfragmentsthree;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import com.abhi.barcode.frag.libv2.BarcodeFragment;
import com.abhi.barcode.frag.libv2.IScanResultHandler;
import com.abhi.barcode.frag.libv2.ScanResult;
import com.google.zxing.BarcodeFormat;
import java.util.EnumSet;
public class MainActivity extends FragmentActivity implements IScanResultHandler {
BarcodeFragment fragment;
Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragment = (BarcodeFragment)getSupportFragmentManager().findFragmentById(R.id.sample);
fragment.setScanResultHandler(this);
btn = ((Button)findViewById(R.id.scan));
btn.setEnabled(false);
// Support for adding decoding type
fragment.setDecodeFor(EnumSet.of(BarcodeFormat.QR_CODE));
}
@Override
public void scanResult(ScanResult result) {
btn.setEnabled(true);
Toast.makeText(this, result.getRawResult().getText(), Toast.LENGTH_LONG).show();
}
public void scanAgain(View v){
fragment.restart();
}
}
这是我的 build.gradle 文件
apply plugin: 'com.android.application'
android {
compileSdkVersion 23
buildToolsVersion "23.0.3"
defaultConfig {
applicationId "apps.radwin.zxingprojectfragmentsthree"
minSdkVersion 16
targetSdkVersion 23
versionCode 1
versionName "1.0"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.4.0'
compile files('libs/barcodelib.jar')
compile files('libs/core.jar')
}
我的ActivityXML>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity">
<fragment
android:id="@+id/sample"
android:name="com.abhi.barcode.frag.libv2.BarcodeFragment"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/scan"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<Button
android:id="@+id/scan"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:onClick="scanAgain"
android:text="Re-Scan" />
</RelativeLayout>
我的例外是：
FATAL EXCEPTION: main
Process: apps.radwin.zxingprojectfragmentsthree, PID: 11692
java.lang.NoClassDefFoundError: Failed resolution of: Lcom/abhi/barcode/frag/libv2/R$string;
at com.abhi.barcode.frag.libv2.BarcodeFragment.displayFrameworkBugMessageAndExit(BarcodeFragment.java:345)
at com.abhi.barcode.frag.libv2.BarcodeFragment.initCamera(BarcodeFragment.java:338)
at com.abhi.barcode.frag.libv2.BarcodeFragment.surfaceCreated(BarcodeFragment.java:212)
at android.view.SurfaceView.updateWindow(SurfaceView.java:712)
at android.view.SurfaceView.onPreDraw(SurfaceView.java:209)
at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:1014)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2510)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1437)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7397)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:920)
at android.view.Choreographer.doCallbacks(Choreographer.java:695)
at android.view.Choreographer.doFrame(Choreographer.java:631)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:906)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.abhi.barcode.frag.libv2.R$string" on path: DexPathList[[zip file "/data/app/apps.radwin.zxingprojectfragmentsthree-1/base.apk"],nativeLibraryDirectories=[/data/app/apps.radwin.zxingprojectfragmentsthree-1/lib/arm64, /vendor/lib64, /system/lib64]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
at com.abhi.barcode.frag.libv2.BarcodeFragment.displayFrameworkBugMessageAndExit(BarcodeFragment.java:345)
at com.abhi.barcode.frag.libv2.BarcodeFragment.initCamera(BarcodeFragment.java:338)
at com.abhi.barcode.frag.libv2.BarcodeFragment.surfaceCreated(BarcodeFragment.java:212)
at android.view.SurfaceView.updateWindow(SurfaceView.java:712)
at android.view.SurfaceView.onPreDraw(SurfaceView.java:209)
at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:1014)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2510)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1437)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7397)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:920)
at android.view.Choreographer.doCallbacks(Choreographer.java:695)
at android.view.Choreographer.doFrame(Choreographer.java:631)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:906)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Suppressed: java.lang.ClassNotFoundException: com.abhi.barcode.frag.libv2.R$string
at java.lang.Class.classForName(Native Method)
at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
... 21 more
Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack trace available
在我的 app/libs 文件夹中，我有两个文件，barcodelib.jar 和 code.jar，
我在我的 android 工作室中右键单击 barcodelib.jar 文件，然后添加为库，我也无法在 core.jar 上按它，它没有提供选项。
你能帮我说说我做错了什么吗？
首先在您的 模块 级别 build.gradle 中，您添加了多次编译 Jar 文件...删除那些并只保留：
dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.4.0'
}
fileTree 已经编译了 app/libs
中的所有 jar 文件
现在从您的 Android 工作室中删除库，就像添加它们一样。
现在右键单击您的项目-> 在资源管理器中显示....
找到你的 libs 的路径并把两个 Jar 文件 barcodelib.jar 和 core.jar
现在在你的 gradle
中注册依赖项
1)打开文件菜单->点击项目结构
2)Select app 这里
3) 单击显示的 依赖项 选项卡
4)点击右上角的加号
5)Select File Dependency 并从 libs 文件夹中找到您的 JAR...
对两个 JAR 文件执行相同的操作
6) 单击确定并应用
7)Select "Sync project with gradle files" 工具栏上的按钮。
8)使缓存无效并重启
更多详细信息来源：http://www.theappguruz.com/blog/external-jar-dependency-android-studio
这应该足够了...如果不够，请post问题中缺少的错误日志的其余部分（还有 21 行...）
从 API 开始，需要在 运行 时间 API 请求 23 级和更高级别的相机权限
将您的 onCreate 代码更改为：
if (PackageManager.PERMISSION_GRANTED == ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CAMERA))
{
// asks primission to use the devices camera
fragment = (BarcodeFragment)getSupportFragmentManager().findFragmentById(R.id.sample);
fragment.setScanResultHandler(this);
btn = ((Button)findViewById(R.id.scan));
btn.setEnabled(false);
// Support for adding decoding type
fragment.setDecodeFor(EnumSet.of(BarcodeFormat.QR_CODE));
}
else
{
requestWritePermission(MainActivity.this);
}
并添加此功能以征求用户的许可：
private static void requestWritePermission(final Context context)
{
if (ActivityCompat.shouldShowRequestPermissionRationale((Activity) context, Manifest.permission.CAMERA))
{
new AlertDialog.Builder(context).setMessage("This app needs permission to use The phone Camera in order to activate the Scanner")
.setPositiveButton("Allow", new DialogInterface.OnClickListener() {
@Override public void onClick(DialogInterface dialog, int which)
{ ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.CAMERA}, 1);}
}).show();
}
else
{
ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.CAMERA}, 1);
}
}
最好在进入片段之前使用它 Activity
添加这些行并重试。
另外，要获得更多信息，请阅读流畅的文章：
https://developer.android.com/training/permissions/requesting.html
我正在尝试启动一个 Activity，里面有一个正在执行 QR 扫描的片段， 我正在为此使用这个库> https://code.google.com/archive/p/barcodefraglibv2/
我按照说明做所有事情，但是当我 运行 应用程序时，它会抛出一个异常：
Failed resolution of: Lcom/abhi/barcode/frag/libv2/R$string
我做错了什么？
这是我的主要内容Activity：
package apps.radwin.zxingprojectfragmentsthree;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import com.abhi.barcode.frag.libv2.BarcodeFragment;
import com.abhi.barcode.frag.libv2.IScanResultHandler;
import com.abhi.barcode.frag.libv2.ScanResult;
import com.google.zxing.BarcodeFormat;
import java.util.EnumSet;
public class MainActivity extends FragmentActivity implements IScanResultHandler {
BarcodeFragment fragment;
Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragment = (BarcodeFragment)getSupportFragmentManager().findFragmentById(R.id.sample);
fragment.setScanResultHandler(this);
btn = ((Button)findViewById(R.id.scan));
btn.setEnabled(false);
// Support for adding decoding type
fragment.setDecodeFor(EnumSet.of(BarcodeFormat.QR_CODE));
}
@Override
public void scanResult(ScanResult result) {
btn.setEnabled(true);
Toast.makeText(this, result.getRawResult().getText(), Toast.LENGTH_LONG).show();
}
public void scanAgain(View v){
fragment.restart();
}
}
这是我的 build.gradle 文件
apply plugin: 'com.android.application'
android {
compileSdkVersion 23
buildToolsVersion "23.0.3"
defaultConfig {
applicationId "apps.radwin.zxingprojectfragmentsthree"
minSdkVersion 16
targetSdkVersion 23
versionCode 1
versionName "1.0"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.4.0'
compile files('libs/barcodelib.jar')
compile files('libs/core.jar')
}
我的ActivityXML>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity">
<fragment
android:id="@+id/sample"
android:name="com.abhi.barcode.frag.libv2.BarcodeFragment"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/scan"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<Button
android:id="@+id/scan"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:onClick="scanAgain"
android:text="Re-Scan" />
</RelativeLayout>
我的例外是：
FATAL EXCEPTION: main
Process: apps.radwin.zxingprojectfragmentsthree, PID: 11692
java.lang.NoClassDefFoundError: Failed resolution of: Lcom/abhi/barcode/frag/libv2/R$string;
at com.abhi.barcode.frag.libv2.BarcodeFragment.displayFrameworkBugMessageAndExit(BarcodeFragment.java:345)
at com.abhi.barcode.frag.libv2.BarcodeFragment.initCamera(BarcodeFragment.java:338)
at com.abhi.barcode.frag.libv2.BarcodeFragment.surfaceCreated(BarcodeFragment.java:212)
at android.view.SurfaceView.updateWindow(SurfaceView.java:712)
at android.view.SurfaceView.onPreDraw(SurfaceView.java:209)
at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:1014)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2510)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1437)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7397)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:920)
at android.view.Choreographer.doCallbacks(Choreographer.java:695)
at android.view.Choreographer.doFrame(Choreographer.java:631)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:906)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.abhi.barcode.frag.libv2.R$string" on path: DexPathList[[zip file "/data/app/apps.radwin.zxingprojectfragmentsthree-1/base.apk"],nativeLibraryDirectories=[/data/app/apps.radwin.zxingprojectfragmentsthree-1/lib/arm64, /vendor/lib64, /system/lib64]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
at com.abhi.barcode.frag.libv2.BarcodeFragment.displayFrameworkBugMessageAndExit(BarcodeFragment.java:345)
at com.abhi.barcode.frag.libv2.BarcodeFragment.initCamera(BarcodeFragment.java:338)
at com.abhi.barcode.frag.libv2.BarcodeFragment.surfaceCreated(BarcodeFragment.java:212)
at android.view.SurfaceView.updateWindow(SurfaceView.java:712)
at android.view.SurfaceView.onPreDraw(SurfaceView.java:209)
at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:1014)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2510)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1437)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7397)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:920)
at android.view.Choreographer.doCallbacks(Choreographer.java:695)
at android.view.Choreographer.doFrame(Choreographer.java:631)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:906)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Suppressed: java.lang.ClassNotFoundException: com.abhi.barcode.frag.libv2.R$string
at java.lang.Class.classForName(Native Method)
at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
... 21 more
Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack trace available
在我的 app/libs 文件夹中，我有两个文件，barcodelib.jar 和 code.jar， 我在我的 android 工作室中右键单击 barcodelib.jar 文件，然后添加为库，我也无法在 core.jar 上按它，它没有提供选项。
你能帮我说说我做错了什么吗？
首先在您的 模块 级别 build.gradle 中，您添加了多次编译 Jar 文件...删除那些并只保留：
dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.4.0'
}
fileTree 已经编译了 app/libs
中的所有 jar 文件现在从您的 Android 工作室中删除库，就像添加它们一样。
现在右键单击您的项目-> 在资源管理器中显示....
找到你的 libs 的路径并把两个 Jar 文件 barcodelib.jar 和 core.jar
现在在你的 gradle
中注册依赖项1)打开文件菜单->点击项目结构
2)Select app 这里
3) 单击显示的 依赖项 选项卡
4)点击右上角的加号
5)Select File Dependency 并从 libs 文件夹中找到您的 JAR... 对两个 JAR 文件执行相同的操作
6) 单击确定并应用
7)Select "Sync project with gradle files" 工具栏上的按钮。
8)使缓存无效并重启
更多详细信息来源：http://www.theappguruz.com/blog/external-jar-dependency-android-studio
这应该足够了...如果不够，请post问题中缺少的错误日志的其余部分（还有 21 行...）
从 API 开始，需要在 运行 时间 API 请求 23 级和更高级别的相机权限
将您的 onCreate 代码更改为：
if (PackageManager.PERMISSION_GRANTED == ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CAMERA))
{
// asks primission to use the devices camera
fragment = (BarcodeFragment)getSupportFragmentManager().findFragmentById(R.id.sample);
fragment.setScanResultHandler(this);
btn = ((Button)findViewById(R.id.scan));
btn.setEnabled(false);
// Support for adding decoding type
fragment.setDecodeFor(EnumSet.of(BarcodeFormat.QR_CODE));
}
else
{
requestWritePermission(MainActivity.this);
}
并添加此功能以征求用户的许可：
private static void requestWritePermission(final Context context)
{
if (ActivityCompat.shouldShowRequestPermissionRationale((Activity) context, Manifest.permission.CAMERA))
{
new AlertDialog.Builder(context).setMessage("This app needs permission to use The phone Camera in order to activate the Scanner")
.setPositiveButton("Allow", new DialogInterface.OnClickListener() {
@Override public void onClick(DialogInterface dialog, int which)
{ ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.CAMERA}, 1);}
}).show();
}
else
{
ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.CAMERA}, 1);
}
}
最好在进入片段之前使用它 Activity 添加这些行并重试。 另外，要获得更多信息，请阅读流畅的文章：
https://developer.android.com/training/permissions/requesting.html