错误:无法连接到相机服务@Android marshmallow

Question

我试图建立一个相机应用程序(我相当新)当我在真实设备上运行应用程序时它给了我这个错误:

    05-26 13:16:37.504 14076-14076/involved.pose9 E/AndroidRuntime: FATAL EXCEPTION: main
                                                            Process: involved.pose9, PID: 14076
                                                            java.lang.RuntimeException: Fail to connect to camera service
                                                                at android.hardware.Camera.<init>(Camera.java:511)
                                                                at android.hardware.Camera.open(Camera.java:368)
                                                                at involved.pose9.CameraActivity.surfaceCreated(CameraActivity.java:63)
                                                                at android.view.SurfaceView.updateWindow(SurfaceView.java:582)
                                                                at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:177)
                                                                at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:944)
                                                                at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2067)
                                                                at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1119)
                                                                at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6060)
                                                                at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
                                                                at android.view.Choreographer.doCallbacks(Choreographer.java:670)
                                                                at android.view.Choreographer.doFrame(Choreographer.java:606)
                                                                at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
                                                                at android.os.Handler.handleCallback(Handler.java:746)
                                                                at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                at android.os.Looper.loop(Looper.java:148)
                                                                at android.app.ActivityThread.main(ActivityThread.java:5443)
                                                                at java.lang.reflect.Method.invoke(Native Method)
                                                                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
                                                                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)

这是我的班级

    import android.graphics.PixelFormat;
    import android.hardware.Camera;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.view.SurfaceHolder;
    import android.view.SurfaceView;
    import android.view.Window;
    import android.view.WindowManager;

    import java.io.IOException;

    public class CameraActivity extends AppCompatActivity implements SurfaceHolder.Callback {

SurfaceHolder mSurfaceHolder;
SurfaceView mSurfaceView;
public Camera mCamera;
boolean mPreviewRunning;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);


    getWindow().setFormat(PixelFormat.TRANSLUCENT);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.activity_camera);
    mSurfaceView = (SurfaceView) findViewById(R.id.surface_camera);
    mSurfaceHolder = mSurfaceView.getHolder();
    mSurfaceHolder.addCallback(this);
    mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

@Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
    // TODO Auto-generated method stub


    if (mPreviewRunning) {
        mCamera.stopPreview();
    }
    Camera.Parameters p = mCamera.getParameters();
    //p.setPreviewSize(w, h);
    mCamera.setParameters(p);
    try {
        mCamera.setPreviewDisplay(arg0);
    } catch (IOException e) {
        e.printStackTrace();
    }
    mCamera.startPreview();
    mPreviewRunning = true;
}

@Override
public void surfaceCreated(SurfaceHolder holder) {
    // TODO Auto-generated method stub
    mCamera = Camera.open();
}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
    // TODO Auto-generated method stub
    mCamera.stopPreview();
    mPreviewRunning = false;
    mCamera.release();
}

Camera.PictureCallback mPictureCallback = new Camera.PictureCallback() {
    public void onPictureTaken(byte[] imageData, Camera c) {
    }
};
}

这有什么不对？提前致谢..

我还在manifest.xml中声明了权限

    <uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.Camera" />
<uses-feature android:name="android.hardware." />

Answer 1

您需要以android.hardware.Camera编程方式授予权限.

清单允许不适用于Android 6

使用棉花糖(最新版本的Android).我们在使用敏感权限方面遇到了一些限制:存储,联系人访问等.在版本中,要在清单中提供这些权限,我们需要在运行时向用户请求它们.

有关更多详细信息,请参阅:Android M权限

在您的活动中添加此代码:

@Override
protected void onStart() {
    super.onStart();

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

        int hasCameraPermission = checkSelfPermission(Manifest.permission.CAMERA);

        List<String> permissions = new ArrayList<String>();

        if (hasCameraPermission != PackageManager.PERMISSION_GRANTED) {
            permissions.add(Manifest.permission.CAMERA);

        } 
        if (!permissions.isEmpty()) {
            requestPermissions(permissions.toArray(new String[permissions.size()]), 111);
        }
    }


}

之后添加onActivityResult:

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    switch (requestCode) {
        case 111: {
            for (int i = 0; i < permissions.length; i++) {
                if (grantResults[i] == PackageManager.PERMISSION_GRANTED) {
                    System.out.println("Permissions --> " + "Permission Granted: " + permissions[i]);


                } else if (grantResults[i] == PackageManager.PERMISSION_DENIED) {
                    System.out.println("Permissions --> " + "Permission Denied: " + permissions[i]);

                }
            }
        }
        break;
        default: {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }
}