北京响应式h5网站开发网站推广的常用方法有哪些
问题与处理策略
问题描述
- 在 Android 项目中，使用相机时，报如下错误
java.lang.RuntimeException: Fail to connect to camera service
# 翻译无法连接到相机服务
问题原因
-
通常情况是应用没有获取到相机权限，导致连接相机服务失败
-
Android 系统要求应用在使用相机之前必须获得相应的权限（声明权限 + 动态请求权限）
处理策略
- 在
AndroidManifest.xml文件中声明权限
<uses-featureandroid:name="android.hardware.camera"android:required="false" />
<uses-permission android:name="android.permission.CAMERA" />
- Android 6.0 及以上需要动态请求权限
private static final int PERMISSION_REQUEST_CAMERA = 1;@Override
protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);EdgeToEdge.enable(this);setContentView(R.layout.activity_permission_test1);ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);return insets;});if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)!= PackageManager.PERMISSION_GRANTED) {Log.i(TAG, "CAMERA - 权限未授予，请求权限");ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.CAMERA},PERMISSION_REQUEST_CAMERA);} else {Log.i(TAG, "CAMERA - 权限已授予，执行相应操作");doCameraOperation();}
}@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {super.onRequestPermissionsResult(requestCode, permissions, grantResults);if (requestCode == PERMISSION_REQUEST_CAMERA) {if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {Log.i(TAG, "CAMERA - 权限已授予，执行相应操作");doCameraOperation();} else {Log.i(TAG, "CAMERA - 权限被拒绝");}}
}private void doCameraOperation() {
}
- Android 6.0 及以上需要动态请求权限（Kotlin 版本）
private val PERMISSION_REQUEST_CAMERA = 1override fun onCreate(savedInstanceState: Bundle?) {super.onCreate(savedInstanceState)enableEdgeToEdge()setContentView(R.layout.activity_permission_test2)ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)insets}if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)!= PackageManager.PERMISSION_GRANTED) {Log.i(TAG, "CAMERA - 权限未授予，请求权限");ActivityCompat.requestPermissions(this,arrayOf(Manifest.permission.CAMERA),PERMISSION_REQUEST_CAMERA)} else {Log.i(TAG, "CAMERA - 权限已授予，执行相应操作");doCameraOperation();}
}override fun onRequestPermissionsResult(requestCode: Int,permissions: Array<out String>,grantResults: IntArray
) {super.onRequestPermissionsResult(requestCode, permissions, grantResults)if (requestCode == PERMISSION_REQUEST_CAMERA) {if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {Log.i(TAG, "CAMERA - 权限已授予，执行相应操作");doCameraOperation()} else {Log.i(TAG, "CAMERA - 权限被拒绝")}}
}private fun doCameraOperation() {
}