Android“权限拒绝:无法使用相机" [英] Android "Permission Denial: can't use the camera"
本文介绍了Android“权限拒绝:无法使用相机"的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在关注有关在Android应用中使用相机的教程.在模拟器和物理设备上运行调试时，出现错误权限被拒绝:无法使用摄像机" .我在清单文件中尝试了各种权限.似乎大多数发生此错误的人都有错别字，缺少权限或权限未在清单中的正确位置.
I'm following a tutorial on utilizing the camera in an Android app. I am getting the error "Permission Denial: can't use the camera" when running debug, both on emulator and physical device. I have tried a variety of permissions in my manifest file. It seems most people who have had this error have had a typo, a missing permission, or the permissions not in the right place in their manifest.
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>
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();
}
}
}
还有我的logcat中的错误:
And the error in my logcat:
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)
我是应用程序开发的新手，并且我不擅长调试，但是从我看到的其他人的文件(以及只有四个月的教程)中，我的清单权限似乎是正确的.
I'm new to app development and admittedly I'm no good at debugging, but my manifest permissions appear to be correct from what I've seen of other people's files (and the tutorial which is only 4 months old).
任何人都可以告诉我我做错了什么吗?
Can anyone please tell me what I've done wrong?
干杯， 李.
更新:我通过调试发现，一旦达到此方法，它就会崩溃...
UPDATE: I found via debugging that it crashes as soon as it reaches this method...
private void openCamera() {
CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
try {
cameraManager.openCamera(mCameraId, mCameraDeviceStateCallback, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
...特别是在它运行try语句后.
... specifically as soon as it runs the try statement.
更新2:如果我注释掉try/catch语句，则该应用程序不会崩溃，但是不会出现预期的结果(即打印"Camera Opened！").有什么想法吗?
UPDATE 2: If I comment out the try/catch statements, the app doesn't crash, but the expected result (which is to print "Camera Opened!") doesn't happen. Any ideas?
更新3:抱歉，我刚刚意识到上面的编辑有多愚蠢.很明显，为什么它不再崩溃，但是至少我现在知道我必须调试cameraManager.openCamera参数.如果有人可以看一下，这里的代码是:)
UPDATE 3: My apologies, I just realized how dumb my above edit was. It's obvious why it no longer crashes, but at least I now know I have to debug my cameraManager.openCamera parameters. The code is there if anyone can have a look :)
推荐答案
如果您使用的是Android 6棉花糖，则此问题可能是由新的权限管理引起的. 就我而言，我通过重写以下活动方法解决了该问题:
If you're using Android 6 Marshmallow this issue could be caused by the new permission management. In my case I solved the problem by overriding the following activity method:
@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;
}
}
然后我使用以下代码启动了需要摄像头(ClassUsingCamera)的活动:
I then launched the activity that requires the camera (ClassUsingCamera) with the following code:
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);
}
在首次启动应用程序时，您会弹出一个对话框，要求您授予对摄像机的访问权限.
On the first app launch you'll get the popup asking you to grant the access to the camera.
另一种选择是使用PermissionsDispatcher，如此处所述 https://github.com/hotchemi/PermissionsDispatcher
Another option is to use the PermissionsDispatcher as explained here https://github.com/hotchemi/PermissionsDispatcher
这篇关于Android“权限拒绝:无法使用相机"的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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