EasyPermissions framework in the Java library explores the technical principles

EasyPermissions is a permissions management framework for Android application development.It simplifies the process of authority requests in the application, and provides a set of easy -to -use APIs, which can more conveniently request and process operating permissions. The technical principles of the EasyPermissions framework are mainly divided into the following aspects: 1. Runtime permissions request: In the Android system, some sensitive permissions need dynamic requests when the application runtime, such as accessing the camera and reading contacts.EasyPermissions is easier to use by encapsulating the authority request method of the Android system.Developers can use the annotations provided by EasyPerMissions to mark the permissions required, and then use the framework API to request permissions.The framework will automatically handle the user permission response and callback, and return the corresponding results. Here are a simple code example to show how to use EasyPerMissions to request camera permissions: @AfterPermissionGranted(RC_CAMERA_PERMISSION) private void requestCameraPermission() { String[] perms = {Manifest.permission.CAMERA}; if (EasyPermissions.hasPermissions(this, perms)) { // I have obtained the camera permission openCamera(); } else { // Request camera permissions EasyPermissions.requestPerMissions (this, "requires camera permissions to take photos", RC_CAMERA_PERMISSION, perms); } } @Override public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { super.onRequestPermissionsResult(requestCode, permissions, grantResults); EasyPermissions.onRequestPermissionsResult(requestCode, permissions, grantResults, this); } @Override public void onPermissionsGranted(int requestCode, @NonNull List<String> perms) { // permissions are granted if (requestCode == RC_CAMERA_PERMISSION) { openCamera(); } } @Override public void onPermissionsDenied(int requestCode, @NonNull List<String> perms) { // Performance is rejected if (requestCode == RC_CAMERA_PERMISSION) { Toast.makeText (this, "Can't get the camera permissions, please grant it manually", toast.length_short) .show (); } } 2. Permanent request results processing: EasyPermissions provides a set of callback methods to process the permissions request results.Developers can handle the right to grant and refuse by implementing the callback method.When the user grants or refuses a certain authority, the framework will automatically call the corresponding callback method so that the developer can perform the next step according to the results. In the above code example, when the camera authority is granted, the `OnPerMissionsgrant" method will be called to execute the logic of opening the camera in this method.When the camera permissions are rejected, the `OnpermissionsonsDenied` method will be called. A prompt message can be displayed in this method to inform the user that the authority is required manually. 3. Permissions after being rejected: For some sensitive permissions, users may choose the "No more question" option. At this time, the request permissions will be directly rejected by the system.EasyPermissions provides a `PermissionRequest` annotation, which can be used to display an explanation dialog box after the permissions are rejected to guide users to manually grant permissions. The following is an example of code using `PermissionRequest` to show the process of explaining the dialog box after the permissions are rejected: @AfterPermissionGranted(RC_CAMERA_PERMISSION) private void requestCameraPermission() { String[] perms = {Manifest.permission.CAMERA}; if (EasyPermissions.hasPermissions(this, perms)) { // I have obtained the camera permission openCamera(); } else { // Request camera permissions EasyPermissions.requestPerMissions (this, "requires camera permissions to take photos", RC_CAMERA_PERMISSION, perms); } } @PermissionRequest(RC_CAMERA_PERMISSION) private void showPermissionExplanation() { // Display the explanation dialog box AlertDialog.Builder builder = new AlertDialog.Builder(this); Builder.settital ("Requirement of camera permissions"); Builder.setMessage ("Please give the application camera permissions in order to take photos"); Builder.setpositiveButton ("Settings", New Dialoginterface.onClickListener () {{) @Override public void onClick(DialogInterface dialog, int which) { // Jump to the application setting page goToAppSettings(); } }); builder.setNegativeButton("取消", null); builder.create().show(); } @Override public void onPermissionsDenied(int requestCode, @NonNull List<String> perms) { // Performance is rejected if (requestCode == RC_CAMERA_PERMISSION) { if (EasyPermissions.somePermissionPermanentlyDenied(this, perms)) { // Display the explanation dialog box showPermissionExplanation(); } else { // Reminder the user to grant permissions Toast.makeText (this, "Can't get the camera permissions, please grant it manually", toast.length_short) .show (); } } } Through the above code example, you can see that when the camera permissions are rejected, it will first determine whether the user chooses "no more inquiry".A simple prompt message will be displayed, prompting the user to grant permissions. The technical principle of the EasyPerMissions framework in the Java class library is to encapsulate the authority request function of the Android system and provide a set of APIs and callback methods that are easy to use to make the permissions requests and processing easier.Developers can use the EasyPerMissions framework to manage the authority in the application and improve user experience and development efficiency. Total number of articles: 498 words