The technical principles and usage methods of the EasyPermissions framework in the Java library analysis
EasyPermissions is a Android library that simplifies the processing of Android permissions.It is based on the Java class library and provides a simple and convenient method to obtain and handle operating permissions.Below will analyze the technical principles and usage methods of the EasyPerMissions framework in the Java class library.
Technical principle:
EasyPermissions uses an annotation -based permission application method.It uses the annotations and reflection mechanisms in Java to implement permissions application and processing.By adding @AafterPerMissionGranted annotations to the method that requires permissions, EasyPermissions automatically process the application and callback of permissions.
Instructions:
1. Add dependencies: Add the following dependencies in the built.gradle file of the project:
dependencies {
implementation 'pub.devrel:easypermissions:3.0.0'
}
2. Add the required permissions to the AndroidManifest.xml file.
3. Add @AterPerMissionGrantedes to the method that requires permissions and specify the request code and required permissions:
@AfterPermissionGranted(RC_CAMERA_PERM)
private void methodWithCameraPermission() {
if (EasyPermissions.hasPermissions(this, Manifest.permission.CAMERA)) {
// has been awarded the right of the camera to perform the camera -related code
openCamera();
} else {
// Apply for camera permissions
EasyPermissions.requestPerMissions (this, "requires camera permissions", RC_CAMERA_PERM, Manifest.Permission.camera);
}
}
4. Process permissions callback:
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
// Pass the result to EasyPermissions
EasyPermissions.onRequestPermissionsResult(requestCode, permissions, grantResults, this);
}
5. Processing permissions application results:
@Override
public void onPermissionsGranted(int requestCode, List<String> perms) {
// The permissions have been granted, and the relevant code is executed
if (requestCode == RC_CAMERA_PERM) {
openCamera();
}
}
@Override
public void onPermissionsDenied(int requestCode, List<String> perms) {
// The permissions are rejected, you can display a prompt message
if (requestCode == RC_CAMERA_PERM) {
Toast.makeText (this, "camera permissions are rejected", toast.length_short) .show ();
}
}
Through the above steps, we can easily use the EasyPerMissions framework to process Android runtime permissions.It not only simplifies the process of permissions application, but also provides a convenient method of callback method to make permission processing simpler and maintainable.
Please note that the above example code is only for demonstration purposes, and it needs to be adjusted according to specific needs in actual use.