那些遇到过的问题

Android"权限拒绝:无法使用相机"

Lee*_*ine 4 android android-camera android-permissions android-camera2

我正在关注在Android应用程序中使用相机的教程.我在模拟器和物理设备上运行调试时收到错误"权限拒绝:无法使用相机".我在清单文件中尝试了各种权限.似乎大多数有此错误的人都有错误,缺少权限或权限不在其清单中的正确位置.

这是我的清单文件:

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

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.FLASHLIGHT" />
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-feature android:name="android.hardware.camera2" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".DBZHome"
            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=".DBZStartPowerUp"
            android:label="@string/title_activity_dbzstart_power_up" >
        </activity>
    </application>

</manifest>
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这是我的活动:

package com.example.karudo.dbzrealpowerup;

import android.app.Activity;
import android.content.Context;
import android.graphics.SurfaceTexture;
import android.hardware.camera2.CameraAccessException;
import android.hardware.camera2.CameraCharacteristics;
import android.hardware.camera2.CameraDevice;
import android.hardware.camera2.CameraManager;
import android.hardware.camera2.params.StreamConfigurationMap;
import android.os.Bundle;
import android.util.Size;
import android.view.Menu;
import android.view.MenuItem;
import android.view.TextureView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class DBZStartPowerUp extends Activity {

    private Size mPreviewSize;
    private String mCameraId;
    private TextureView mTextureView;
    private TextureView.SurfaceTextureListener mSurfaceTextureListener =
            new TextureView.SurfaceTextureListener() {

                @Override
                public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
                    setupCamera(width, height);
                    openCamera();
                }

                @Override
                public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {

                }

                @Override
                public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
                    return false;
                }

                @Override
                public void onSurfaceTextureUpdated(SurfaceTexture surface) {

                }
            };

    private CameraDevice mCameraDevice;
    private CameraDevice.StateCallback mCameraDeviceStateCallback
            = new CameraDevice.StateCallback() {

        @Override
        public void onOpened(CameraDevice camera) {
            mCameraDevice = camera;
            Toast.makeText(getApplicationContext(), "Camera Opened!", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onDisconnected(CameraDevice camera) {
            camera.close();
            mCameraDevice = null;
        }

        @Override
        public void onError(CameraDevice camera, int error) {
            camera.close();
            mCameraDevice = null;
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_dbzstartpowerup);
        mTextureView = (TextureView) findViewById(R.id.dbzCameraPreview);
    }

    @Override
    public void onResume() {
        super.onResume();
        if(mTextureView.isAvailable()) {

        } else {
            mTextureView.setSurfaceTextureListener(mSurfaceTextureListener);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_dbzstartpowerup, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    private void setupCamera(int width, int height) {
        CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
        try {
            for(String cameraId : cameraManager.getCameraIdList()) {
                CameraCharacteristics cameraCharacteristics = cameraManager.getCameraCharacteristics(cameraId);
                if (cameraCharacteristics.get(CameraCharacteristics.LENS_FACING) ==
                        CameraCharacteristics.LENS_FACING_FRONT) {
                    continue;
                }
                StreamConfigurationMap map = cameraCharacteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
                mPreviewSize = getPreferredPreviewSize(map.getOutputSizes(SurfaceTexture.class), width, height);
                mCameraId = cameraId;
                return;
            }
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    private Size getPreferredPreviewSize(Size[] mapSizes, int width, int height) {
        List<Size> collectorSizes = new ArrayList<>();
        for(Size option : mapSizes) {
            if(width > height) {
                if(option.getWidth() > width &&
                        option.getHeight() > height) {
                    collectorSizes.add(option);
                }
            } else {
                if(option.getWidth() > height &&
                        option.getHeight() > width) {
                    collectorSizes.add(option);
                }
            }
        }
        if(collectorSizes.size() > 0) {
            return Collections.min(collectorSizes, new Comparator<Size>() {
                @Override
                public int compare(Size lhs, Size rhs) {
                    return Long.signum(lhs.getWidth() * lhs.getHeight() - rhs.getWidth() * rhs.getHeight());
                }
            });
        }
        return mapSizes[0];
    }

    private void openCamera() {
        CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
        try {
            cameraManager.openCamera(mCameraId, mCameraDeviceStateCallback, null);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }
}
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我的logcat中的错误:

10-04 03:15:02.740     961-8780/? E/CameraService? Permission Denial: can't use the camera pid=20601, uid=10059
10-04 03:15:02.741  20601-20601/com.example.karudo.dbzrealpowerup E/AndroidRuntime? FATAL EXCEPTION: main
    Process: com.example.karudo.dbzrealpowerup, PID: 20601
    java.lang.SecurityException: Lacking privileges to access camera service
            at android.hardware.camera2.utils.CameraBinderDecorator.throwOnError(CameraBinderDecorator.java:108)
            at android.hardware.camera2.legacy.CameraDeviceUserShim.connectBinderShim(CameraDeviceUserShim.java:336)
            at android.hardware.camera2.CameraManager.openCameraDeviceUserAsync(CameraManager.java:324)
            at android.hardware.camera2.CameraManager.openCamera(CameraManager.java:454)
            at com.example.karudo.dbzrealpowerup.DBZStartPowerUp.openCamera(DBZStartPowerUp.java:163)
            at com.example.karudo.dbzrealpowerup.DBZStartPowerUp.access$100(DBZStartPowerUp.java:23)
            at com.example.karudo.dbzrealpowerup.DBZStartPowerUp$1.onSurfaceTextureAvailable(DBZStartPowerUp.java:34)
            at android.view.TextureView.getHardwareLayer(TextureView.java:368)
            at android.view.View.updateDisplayListIfDirty(View.java:15151)
            at android.view.View.draw(View.java:15948)
            at android.view.ViewGroup.drawChild(ViewGroup.java:3609)
            at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3399)
            at android.view.View.updateDisplayListIfDirty(View.java:15169)
            at android.view.View.draw(View.java:15948)
            at android.view.ViewGroup.drawChild(ViewGroup.java:3609)
            at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3399)
            at android.view.View.updateDisplayListIfDirty(View.java:15169)
            at android.view.View.draw(View.java:15948)
            at android.view.ViewGroup.drawChild(ViewGroup.java:3609)
            at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3399)
            at android.view.View.updateDisplayListIfDirty(View.java:15169)
            at android.view.View.draw(View.java:15948)
            at android.view.ViewGroup.drawChild(ViewGroup.java:3609)
            at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3399)
            at android.view.View.draw(View.java:16181)
            at com.android.internal.policy.PhoneWindow$DecorView.draw(PhoneWindow.java:2690)
            at android.view.View.updateDisplayListIfDirty(View.java:15174)
            at android.view.ThreadedRenderer.updateViewTreeDisplayList(ThreadedRenderer.java:281)
            at android.view.ThreadedRenderer.updateRootDisplayList(ThreadedRenderer.java:287)
            at android.view.ThreadedRenderer.draw(ThreadedRenderer.java:322)
            at android.view.ViewRootImpl.draw(ViewRootImpl.java:2615)
            at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2434)
            at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2067)
            at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107)
            at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013)
            at android.view.Choreographer$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$FrameDisplayEventReceiver.run(Choreographer.java:844)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:148)
            at android.app.ActivityThread.main(ActivityThread.java:5417)
            at java.lang.reflect.Method.invoke(Native Method)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
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我是应用程序开发的新手,不可否认我不擅长调试,但我的清单权限似乎与我所看到的其他人的文件(以及仅4个月大的教程)相同.

谁能告诉我我做错了什么？

干杯,李.

更新:我通过调试发现它一旦到达此方法就会崩溃...

private void openCamera() {
    CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
    try {
        cameraManager.openCamera(mCameraId, mCameraDeviceStateCallback, null);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
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}

...特别是一旦它运行try语句.

更新2:如果我注释掉try/catch语句,应用程序不会崩溃,但预期的结果(即打印"Camera Opened!")不会发生.有任何想法吗？

更新3:道歉,我刚刚意识到我上面的编辑是多么愚蠢.很明显为什么它不再崩溃,但至少我现在知道我必须调试我的cameraManager.openCamera参数.如果有人可以看看代码是那里:)

Rob*_*rto 10

如果您使用的是Android 6 Marshmallow,则此问题可能是由新的权限管理引起的.在我的情况下,我通过重写以下活动方法解决了这个问题:

@Override
public void onRequestPermissionsResult(int requestCode,  String permissions[], int[] grantResults) {
    switch (requestCode) {
        case CAMERA_PERMISSION:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                if(mClss != null) {
                    Intent intent = new Intent(this, ClassUsingCamera);
                    startActivity(intent);
                }
            } else {
                Toast.makeText(this, "Please grant camera permission to use the QR Scanner", Toast.LENGTH_SHORT).show();
            }
            return;
    }
}
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然后,我使用以下代码启动了需要摄像头的活动(ClassUsingCamera):

if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
                != PackageManager.PERMISSION_GRANTED) {
     ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.CAMERA}, CAMERA_PERMISSION);
} else {
       Intent intent = new Intent(this, ClassUsingCamera);
       startActivity(intent);
        }
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在第一个应用程序启动时,您将获得弹出窗口,要求您授予对摄像头的访问权限.

另一种选择是使用PermissionsDispatcher,如下所述https://github.com/hotchemi/PermissionsDispatcher

uma*_*uma 0

尝试将此代码放入您的manifest.xml 文件中。

 <uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="19" />

<uses-permission
    android:name="android.permission.INTERNET"
    android:maxSdkVersion="19" />
<uses-permission android:name="android.permission.SET_WALLPAPER" />
<uses-permission android:name="android.permission.SET_DEBUG_APP"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
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