在Zxing条码应用程序中获取相机错误

Question

我正在尝试使用Zxing Library开发条形码扫描仪.

我的活动如下:

public class Scanner extends Activity {  

    private static final String PACKAGE = "com.test.scan";  
    private static final String SCANNER = "com.google.zxing.client.android.SCAN";  
    private static final String SCAN_FORMATS = "UPC_A,UPC_E,EAN_8,EAN_13,CODE_39,CODE_93,CODE_128";  
    private static final String SCAN_MODE = "QR_CODE_MODE";  
    public static final int REQUEST_CODE = 1;  

    @Override  
    public void onCreate(Bundle icicle) {  
        super.onCreate(icicle);  

        setContentView(R.layout.main);  

         Button ok;  
         ok = (Button) findViewById(R.id.b1);  
         ok.setOnClickListener(new View.OnClickListener() {  

             public void onClick(View v) {  

                Intent scanIntent = new Intent(SCANNER);  
                scanIntent.setPackage(PACKAGE);  
                scanIntent.addCategory(Intent.CATEGORY_DEFAULT);  
                scanIntent.putExtra("SCAN_FORMATS", SCAN_FORMATS);  
                scanIntent.putExtra("SCAN_MODE", SCAN_MODE);  
                try {  
                    startActivityForResult(scanIntent, REQUEST_CODE);  
                } catch (ActivityNotFoundException e) {  
                     // TODO: Exception handling  
                }  
            }  

        });  
     }

也是清单文件:

    <activity android:name=".Scanner"
            android:screenOrientation="landscape"   android:configChanges="orientation|keyboardHidden"
            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.LAUNCHER" />  
            </intent-filter>

</activity>

<activity android:name="com.google.zxing.client.android.CaptureActivity"
                android:screenOrientation="landscape" android:configChanges="orientation|keyboardHidden"  
                android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
                android:windowSoftInputMode="stateAlwaysHidden">
                <intent-filter>
                    <action     android:name="com.google.zxing.client.android.SCAN" />
                    <category    android:name="android.intent.category.DEFAULT" />
                </intent-filter>
            </activity>
            <activity android:name="com.google.zxing.client.android.PreferencesActivity"
                android:label="@string/preferences_name">
            </activity>
            <activity android:name="com.google.zxing.client.android.HelpActivity"
                android:screenOrientation="user">
                <intent-filter>
                    <action android:name="android.intent.action.VIEW" />
                    <category android:name="android.intent.category.DEFAULT" />
                </intent-filter>
            </activity>
            <activity android:name="com.google.zxing.client.android.share.ShareActivity"
                android:label="@string/share_name" android:screenOrientation="user"
                android:theme="@android:style/Theme.Light">
                <intent-filter>
                    <action android:name="com.google.zxing.client.android.SHARE" />
                    <category android:name="android.intent.category.DEFAULT" />
                </intent-filter>
            </activity>
    <uses-permission android:name="android.permission.CAMERA"

但是我收到以下错误:

"抱歉,Android相机遇到问题.您可能需要重启设备".

我关注了一些博客.

日志:

   Unexpected error initializating camera  
    01-27 10:40:48.281: WARN/CaptureActivity(1007): java.lang.RuntimeException: Fail to connect to camera service  
    01-27 10:40:48.281: WARN/CaptureActivity(1007):     at android.hardware.Camera.native_setup(Native Method)  
    01-27 10:40:48.281: WARN/CaptureActivity(1007):     at android.hardware.Camera.<init>(Camera.java:185)  
    01-27 10:40:48.281: WARN/CaptureActivity(1007):     at android.hardware.Camera.open(Camera.java:165)
   01-27 10:40:48.281: WARN/CaptureActivity(1007):     at com.google.zxing.client.android.camera.CameraManager.openDriver(CameraManager.java:126)
    01-27 10:40:48.281: WARN/CaptureActivity(1007):     at com.google.zxing.client.android.CaptureActivity.initCamera(CaptureActivity.java:606)  
    01-27 10:40:48.281: WARN/CaptureActivity(1007):     at com.google.zxing.client.android.CaptureActivity.surfaceCreated(CaptureActivity.java:346)   
    01-27 10:40:48.281: WARN/CaptureActivity(1007):     at android.view.SurfaceView.updateWindow(SurfaceView.java:532)  
    01-27 10:40:48.281: WARN/CaptureActivity(1007):     at android.view.SurfaceView.dispatchDraw(SurfaceView.java:339) 

Answer 1

对于Android 6+,由于"权限"问题,如果您收到消息"抱歉,相机遇到问题.您可能需要重启设备.",转到设置 - 应用 - 找到"您的应用名称" - 选择权限并打开"相机".

Answer 2

相机许可

<uses-permission android:name="android.permission.CAMERA"

不在适当的地方.应该在申请标签之后.

Answer 3

这意味着返回的设备null从Camera.open()它不应该永远做.它被视为设备错误.我不确定你会如何调试它为什么这样做,但这就是原因.

我唯一一次看到这种情况发生在Android 2.2设备上,只有前置摄像头.用于访问前置摄像头的API仅出现在Android 2.3中,之前的Camera.open()API方法可能仅返回后置摄像头.所以这些回归null.它确实是一个设备错误,因为他们真的需要运行Android 2.3才能让应用程序使用前置摄像头.