Delphi 10.3实现Android App的动态权限申请

Delphi 10.3 RIO发布近两个月，针对Google Play的要求，完美实现了对Android 8的支持，即对Android API Level 26的支持。这支持当中，最主要的得算是动态申请应用权限，现在我们来看看，如何在自己的app中动态申请权限？

下面的代码，是10.3封装的Android权限列表，这些权限，我们都可以动态申请。

    {class} property ACCESS_CHECKIN_PROPERTIES: JString read _GetACCESS_CHECKIN_PROPERTIES;
    {class} property ACCESS_COARSE_LOCATION: JString read _GetACCESS_COARSE_LOCATION;
    {class} property ACCESS_FINE_LOCATION: JString read _GetACCESS_FINE_LOCATION;
    {class} property ACCESS_LOCATION_EXTRA_COMMANDS: JString read _GetACCESS_LOCATION_EXTRA_COMMANDS;
    {class} property ACCESS_NETWORK_STATE: JString read _GetACCESS_NETWORK_STATE;
    {class} property ACCESS_NOTIFICATION_POLICY: JString read _GetACCESS_NOTIFICATION_POLICY;
    {class} property ACCESS_WIFI_STATE: JString read _GetACCESS_WIFI_STATE;
    {class} property ACCOUNT_MANAGER: JString read _GetACCOUNT_MANAGER;
    {class} property ADD_VOICEMAIL: JString read _GetADD_VOICEMAIL;
    {class} property ANSWER_PHONE_CALLS: JString read _GetANSWER_PHONE_CALLS;
    {class} property BATTERY_STATS: JString read _GetBATTERY_STATS;
    {class} property BIND_ACCESSIBILITY_SERVICE: JString read _GetBIND_ACCESSIBILITY_SERVICE;
    {class} property BIND_APPWIDGET: JString read _GetBIND_APPWIDGET;
    {class} property BIND_AUTOFILL_SERVICE: JString read _GetBIND_AUTOFILL_SERVICE;
    {class} property BIND_CARRIER_MESSAGING_SERVICE: JString read _GetBIND_CARRIER_MESSAGING_SERVICE;
    {class} property BIND_CARRIER_SERVICES: JString read _GetBIND_CARRIER_SERVICES;
    {class} property BIND_CHOOSER_TARGET_SERVICE: JString read _GetBIND_CHOOSER_TARGET_SERVICE;
    {class} property BIND_CONDITION_PROVIDER_SERVICE: JString read _GetBIND_CONDITION_PROVIDER_SERVICE;
    {class} property BIND_DEVICE_ADMIN: JString read _GetBIND_DEVICE_ADMIN;
    {class} property BIND_DREAM_SERVICE: JString read _GetBIND_DREAM_SERVICE;
    {class} property BIND_INCALL_SERVICE: JString read _GetBIND_INCALL_SERVICE;
    {class} property BIND_INPUT_METHOD: JString read _GetBIND_INPUT_METHOD;
    {class} property BIND_MIDI_DEVICE_SERVICE: JString read _GetBIND_MIDI_DEVICE_SERVICE;
    {class} property BIND_NFC_SERVICE: JString read _GetBIND_NFC_SERVICE;
    {class} property BIND_NOTIFICATION_LISTENER_SERVICE: JString read _GetBIND_NOTIFICATION_LISTENER_SERVICE;
    {class} property BIND_PRINT_SERVICE: JString read _GetBIND_PRINT_SERVICE;
    {class} property BIND_QUICK_SETTINGS_TILE: JString read _GetBIND_QUICK_SETTINGS_TILE;
    {class} property BIND_REMOTEVIEWS: JString read _GetBIND_REMOTEVIEWS;
    {class} property BIND_SCREENING_SERVICE: JString read _GetBIND_SCREENING_SERVICE;
    {class} property BIND_TELECOM_CONNECTION_SERVICE: JString read _GetBIND_TELECOM_CONNECTION_SERVICE;
    {class} property BIND_TEXT_SERVICE: JString read _GetBIND_TEXT_SERVICE;
    {class} property BIND_TV_INPUT: JString read _GetBIND_TV_INPUT;
    {class} property BIND_VISUAL_VOICEMAIL_SERVICE: JString read _GetBIND_VISUAL_VOICEMAIL_SERVICE;
    {class} property BIND_VOICE_INTERACTION: JString read _GetBIND_VOICE_INTERACTION;
    {class} property BIND_VPN_SERVICE: JString read _GetBIND_VPN_SERVICE;
    {class} property BIND_VR_LISTENER_SERVICE: JString read _GetBIND_VR_LISTENER_SERVICE;
    {class} property BIND_WALLPAPER: JString read _GetBIND_WALLPAPER;
    {class} property BLUETOOTH: JString read _GetBLUETOOTH;
    {class} property BLUETOOTH_ADMIN: JString read _GetBLUETOOTH_ADMIN;
    {class} property BLUETOOTH_PRIVILEGED: JString read _GetBLUETOOTH_PRIVILEGED;
    {class} property BODY_SENSORS: JString read _GetBODY_SENSORS;
    {class} property BROADCAST_PACKAGE_REMOVED: JString read _GetBROADCAST_PACKAGE_REMOVED;
    {class} property BROADCAST_SMS: JString read _GetBROADCAST_SMS;
    {class} property BROADCAST_STICKY: JString read _GetBROADCAST_STICKY;
    {class} property BROADCAST_WAP_PUSH: JString read _GetBROADCAST_WAP_PUSH;
    {class} property CALL_PHONE: JString read _GetCALL_PHONE;
    {class} property CALL_PRIVILEGED: JString read _GetCALL_PRIVILEGED;
    {class} property CAMERA: JString read _GetCAMERA;
    {class} property CAPTURE_AUDIO_OUTPUT: JString read _GetCAPTURE_AUDIO_OUTPUT;
    {class} property CAPTURE_SECURE_VIDEO_OUTPUT: JString read _GetCAPTURE_SECURE_VIDEO_OUTPUT;
    {class} property CAPTURE_VIDEO_OUTPUT: JString read _GetCAPTURE_VIDEO_OUTPUT;
    {class} property CHANGE_COMPONENT_ENABLED_STATE: JString read _GetCHANGE_COMPONENT_ENABLED_STATE;
    {class} property CHANGE_CONFIGURATION: JString read _GetCHANGE_CONFIGURATION;
    {class} property CHANGE_NETWORK_STATE: JString read _GetCHANGE_NETWORK_STATE;
    {class} property CHANGE_WIFI_MULTICAST_STATE: JString read _GetCHANGE_WIFI_MULTICAST_STATE;
    {class} property CHANGE_WIFI_STATE: JString read _GetCHANGE_WIFI_STATE;
    {class} property CLEAR_APP_CACHE: JString read _GetCLEAR_APP_CACHE;
    {class} property CONTROL_LOCATION_UPDATES: JString read _GetCONTROL_LOCATION_UPDATES;
    {class} property DELETE_CACHE_FILES: JString read _GetDELETE_CACHE_FILES;
    {class} property DELETE_PACKAGES: JString read _GetDELETE_PACKAGES;
    {class} property DIAGNOSTIC: JString read _GetDIAGNOSTIC;
    {class} property DISABLE_KEYGUARD: JString read _GetDISABLE_KEYGUARD;
    {class} property DUMP: JString read _GetDUMP;
    {class} property EXPAND_STATUS_BAR: JString read _GetEXPAND_STATUS_BAR;
    {class} property FACTORY_TEST: JString read _GetFACTORY_TEST;
    {class} property GET_ACCOUNTS: JString read _GetGET_ACCOUNTS;
    {class} property GET_ACCOUNTS_PRIVILEGED: JString read _GetGET_ACCOUNTS_PRIVILEGED;
    {class} property GET_PACKAGE_SIZE: JString read _GetGET_PACKAGE_SIZE;
    {class} property GET_TASKS: JString read _GetGET_TASKS;
    {class} property GLOBAL_SEARCH: JString read _GetGLOBAL_SEARCH;
    {class} property INSTALL_LOCATION_PROVIDER: JString read _GetINSTALL_LOCATION_PROVIDER;
    {class} property INSTALL_PACKAGES: JString read _GetINSTALL_PACKAGES;
    {class} property INSTALL_SHORTCUT: JString read _GetINSTALL_SHORTCUT;
    {class} property INSTANT_APP_FOREGROUND_SERVICE: JString read _GetINSTANT_APP_FOREGROUND_SERVICE;
    {class} property INTERNET: JString read _GetINTERNET;
    {class} property KILL_BACKGROUND_PROCESSES: JString read _GetKILL_BACKGROUND_PROCESSES;
    {class} property LOCATION_HARDWARE: JString read _GetLOCATION_HARDWARE;
    {class} property MANAGE_DOCUMENTS: JString read _GetMANAGE_DOCUMENTS;
    {class} property MANAGE_OWN_CALLS: JString read _GetMANAGE_OWN_CALLS;
    {class} property MASTER_CLEAR: JString read _GetMASTER_CLEAR;
    {class} property MEDIA_CONTENT_CONTROL: JString read _GetMEDIA_CONTENT_CONTROL;
    {class} property MODIFY_AUDIO_SETTINGS: JString read _GetMODIFY_AUDIO_SETTINGS;
    {class} property MODIFY_PHONE_STATE: JString read _GetMODIFY_PHONE_STATE;
    {class} property MOUNT_FORMAT_FILESYSTEMS: JString read _GetMOUNT_FORMAT_FILESYSTEMS;
    {class} property MOUNT_UNMOUNT_FILESYSTEMS: JString read _GetMOUNT_UNMOUNT_FILESYSTEMS;
    {class} property NFC: JString read _GetNFC;
    {class} property PACKAGE_USAGE_STATS: JString read _GetPACKAGE_USAGE_STATS;
    {class} property PERSISTENT_ACTIVITY: JString read _GetPERSISTENT_ACTIVITY;
    {class} property PROCESS_OUTGOING_CALLS: JString read _GetPROCESS_OUTGOING_CALLS;
    {class} property READ_CALENDAR: JString read _GetREAD_CALENDAR;
    {class} property READ_CALL_LOG: JString read _GetREAD_CALL_LOG;
    {class} property READ_CONTACTS: JString read _GetREAD_CONTACTS;
    {class} property READ_EXTERNAL_STORAGE: JString read _GetREAD_EXTERNAL_STORAGE;
    {class} property READ_FRAME_BUFFER: JString read _GetREAD_FRAME_BUFFER;
    {class} property READ_INPUT_STATE: JString read _GetREAD_INPUT_STATE;
    {class} property READ_LOGS: JString read _GetREAD_LOGS;
    {class} property READ_PHONE_NUMBERS: JString read _GetREAD_PHONE_NUMBERS;
    {class} property READ_PHONE_STATE: JString read _GetREAD_PHONE_STATE;
    {class} property READ_SMS: JString read _GetREAD_SMS;
    {class} property READ_SYNC_SETTINGS: JString read _GetREAD_SYNC_SETTINGS;
    {class} property READ_SYNC_STATS: JString read _GetREAD_SYNC_STATS;
    {class} property READ_VOICEMAIL: JString read _GetREAD_VOICEMAIL;
    {class} property REBOOT: JString read _GetREBOOT;
    {class} property RECEIVE_BOOT_COMPLETED: JString read _GetRECEIVE_BOOT_COMPLETED;
    {class} property RECEIVE_MMS: JString read _GetRECEIVE_MMS;
    {class} property RECEIVE_SMS: JString read _GetRECEIVE_SMS;
    {class} property RECEIVE_WAP_PUSH: JString read _GetRECEIVE_WAP_PUSH;
    {class} property RECORD_AUDIO: JString read _GetRECORD_AUDIO;
    {class} property REORDER_TASKS: JString read _GetREORDER_TASKS;
    {class} property REQUEST_COMPANION_RUN_IN_BACKGROUND: JString read _GetREQUEST_COMPANION_RUN_IN_BACKGROUND;
    {class} property REQUEST_COMPANION_USE_DATA_IN_BACKGROUND: JString read _GetREQUEST_COMPANION_USE_DATA_IN_BACKGROUND;
    {class} property REQUEST_DELETE_PACKAGES: JString read _GetREQUEST_DELETE_PACKAGES;
    {class} property REQUEST_IGNORE_BATTERY_OPTIMIZATIONS: JString read _GetREQUEST_IGNORE_BATTERY_OPTIMIZATIONS;
    {class} property REQUEST_INSTALL_PACKAGES: JString read _GetREQUEST_INSTALL_PACKAGES;
    {class} property RESTART_PACKAGES: JString read _GetRESTART_PACKAGES;
    {class} property SEND_RESPOND_VIA_MESSAGE: JString read _GetSEND_RESPOND_VIA_MESSAGE;
    {class} property SEND_SMS: JString read _GetSEND_SMS;
    {class} property SET_ALARM: JString read _GetSET_ALARM;
    {class} property SET_ALWAYS_FINISH: JString read _GetSET_ALWAYS_FINISH;
    {class} property SET_ANIMATION_SCALE: JString read _GetSET_ANIMATION_SCALE;
    {class} property SET_DEBUG_APP: JString read _GetSET_DEBUG_APP;
    {class} property SET_PREFERRED_APPLICATIONS: JString read _GetSET_PREFERRED_APPLICATIONS;
    {class} property SET_PROCESS_LIMIT: JString read _GetSET_PROCESS_LIMIT;
    {class} property SET_TIME: JString read _GetSET_TIME;
    {class} property SET_TIME_ZONE: JString read _GetSET_TIME_ZONE;
    {class} property SET_WALLPAPER: JString read _GetSET_WALLPAPER;
    {class} property SET_WALLPAPER_HINTS: JString read _GetSET_WALLPAPER_HINTS;
    {class} property SIGNAL_PERSISTENT_PROCESSES: JString read _GetSIGNAL_PERSISTENT_PROCESSES;
    {class} property STATUS_BAR: JString read _GetSTATUS_BAR;
    {class} property SYSTEM_ALERT_WINDOW: JString read _GetSYSTEM_ALERT_WINDOW;
    {class} property TRANSMIT_IR: JString read _GetTRANSMIT_IR;
    {class} property UNINSTALL_SHORTCUT: JString read _GetUNINSTALL_SHORTCUT;
    {class} property UPDATE_DEVICE_STATS: JString read _GetUPDATE_DEVICE_STATS;
    {class} property USE_FINGERPRINT: JString read _GetUSE_FINGERPRINT;
    {class} property USE_SIP: JString read _GetUSE_SIP;
    {class} property VIBRATE: JString read _GetVIBRATE;
    {class} property WAKE_LOCK: JString read _GetWAKE_LOCK;
    {class} property WRITE_APN_SETTINGS: JString read _GetWRITE_APN_SETTINGS;
    {class} property WRITE_CALENDAR: JString read _GetWRITE_CALENDAR;
    {class} property WRITE_CALL_LOG: JString read _GetWRITE_CALL_LOG;
    {class} property WRITE_CONTACTS: JString read _GetWRITE_CONTACTS;
    {class} property WRITE_EXTERNAL_STORAGE: JString read _GetWRITE_EXTERNAL_STORAGE;
    {class} property WRITE_GSERVICES: JString read _GetWRITE_GSERVICES;
    {class} property WRITE_SECURE_SETTINGS: JString read _GetWRITE_SECURE_SETTINGS;
    {class} property WRITE_SETTINGS: JString read _GetWRITE_SETTINGS;
    {class} property WRITE_SYNC_SETTINGS: JString read _GetWRITE_SYNC_SETTINGS;
    {class} property WRITE_VOICEMAIL: JString read _GetWRITE_VOICEMAIL

上面的代码，在Androidapi.JNI.Os单元，通过类TJManifest_permission可以得到名称，如下面的代码，取得相机的权限名称，存到FPermissionCamera字符串变量中。

  FPermissionCamera := JStringToString(TJManifest_permission.JavaClass.CAMERA);

为了在app运行期来申请对应的权限，10.3还实现了一个服务类：TPermissionsService，并且通过PermissionsService方法返回该类的实例，通过该实例的RequestPermissions方法申请权限：

  PermissionsService.RequestPermissions([FPermissionCamera, FPermissionReadExternalStorage, FPermissionWriteExternalStorage], TakePicturePermissionRequestResult, DisplayRationale);

RequestPermissions方法，功能如其名，申请权限。象上面的代码，要传递三个参数，先看一下这个方法的原型：

    procedure RequestPermissions(const APermissions: TArray<string>;
      const AOnRequestPermissionsResult: TRequestPermissionsResultEvent; AOnDisplayRationale: TDisplayRationaleEvent = nil);
      overload; virtual;

APermissions：权限名称数组，例如：[FPermissionCamera, FPermissionReadExternalStorage, FPermissionWriteExternalStorage]

AOnRequestPermissionsResult：TRequestPermissionsResultEvent，申请权限后触发的事件，我们要做一个TRequestPermissionsResultEvent函数，来接管动态申请后的逻辑。

AOnDisplayRationale: TDisplayRationaleEvent：例用这个事件，异步的向用户显示申请权限的解释说明，用户看到这个解释后，通过代码来支持用户来进一步请求权限。注意，千万不要阻止此线程等待用户的响应！

综上所述，我们现在可以看看实现动态申请app权限的代码步骤了：
1.声明app需要申请的权限名称变量

    //动态申请权限
    FPermissionCamera,
    FPermissionReadExternalStorage,
    FPermissionWriteExternalStorage: string;

2.在app启动时通过TJManifest_permission取得权限名称并赋值给权限名称变量

procedure TMainForm.FormCreate(Sender: TObject);
begin
{$IFDEF ANDROID}
  FPermissionCamera := JStringToString(TJManifest_permission.JavaClass.CAMERA);
  FPermissionReadExternalStorage := JStringToString(TJManifest_permission.JavaClass.READ_EXTERNAL_STORAGE);
  FPermissionWriteExternalStorage := JStringToString(TJManifest_permission.JavaClass.WRITE_EXTERNAL_STORAGE);
{$ENDIF}

接下来，我们要准备两个方法，准备做为PermissionsService.RequestPermissions方法的参数，即请求权限时的回调函数，来处理权限请求的结果及给用户的权限解释信息。

3.实现TRequestPermissionsResultEvent方法

procedure TMainForm.TakePicturePermissionRequestResult(Sender: TObject; const APermissions: TArray<string>; const AGrantResults: TArray<TPermissionStatus>);
begin

 // 申请的3个权限: CAMERA, READ_EXTERNAL_STORAGE and WRITE_EXTERNAL_STORAGE
  if (Length(AGrantResults) = 3) and (AGrantResults[0] = TPermissionStatus.Granted) and (AGrantResults[1] = TPermissionStatus.Granted) and (AGrantResults[2] = TPermissionStatus.Granted) then
  begin
    //权限被用户允许的代码
  end
  else
    //权限被用户禁止的代码
    TDialogService.ShowMessage('权限禁止，不能拍照.')

end;

4.实现TDisplayRationaleEvent方法

procedure TMainForm.DisplayRationale(Sender: TObject; const APermissions: TArray<string>; const APostRationaleProc: TProc);
var
  I: Integer;
  RationaleMsg: string;
begin
  for I := 0 to High(APermissions) do
  begin
    if APermissions[I] = FPermissionCamera then
      RationaleMsg := RationaleMsg + '应用需要拍照' + SLineBreak + SLineBreak
    else if APermissions[I] = FPermissionReadExternalStorage then
      RationaleMsg := RationaleMsg + '应用需要读取照片';
  end;

  TDialogService.ShowMessage(RationaleMsg,
    procedure(const AResult: TModalResult)
    begin
      APostRationaleProc;
    end)

end;

5.用PermissionsService.RequestPermissions在app启动时申请权限

procedure TMainForm.FormCreate(Sender: TObject);
begin
{$IFDEF ANDROID}
  FPermissionCamera := JStringToString(TJManifest_permission.JavaClass.CAMERA);
  FPermissionReadExternalStorage := JStringToString(TJManifest_permission.JavaClass.READ_EXTERNAL_STORAGE);
  FPermissionWriteExternalStorage := JStringToString(TJManifest_permission.JavaClass.WRITE_EXTERNAL_STORAGE);
{$ENDIF}

  PermissionsService.RequestPermissions([FPermissionCamera, FPermissionReadExternalStorage, FPermissionWriteExternalStorage], TakePicturePermissionRequestResult, DisplayRationale);

到此，实现了动态申请app权限。具体的代码，可以到ChinaCock QQ群223717588去下载。

小年刚过，新年马上到来，在此先祝大家春节快乐，多多发财，流行的话说，1919，想啥啥有！

2020-07-01，官方给的参考代码：

 

procedure TLocationForm.swLocationSensorActiveSwitch(Sender: TObject);
begin
{$IFDEF ANDROID}
  if swLocationSensorActive.IsChecked then
    PermissionsService.RequestPermissions([JStringToString(TJManifest_permission.JavaClass.ACCESS_FINE_LOCATION)],
      procedure(const APermissions: TArray<string>; const AGrantResults: TArray<TPermissionStatus>)
      begin
        if (Length(AGrantResults) = 1) and (AGrantResults[0] = TPermissionStatus.Granted) then
          { activate or deactivate the location sensor }
          LocationSensor1.Active := True
        else
        begin
          swLocationSensorActive.IsChecked := False;
          TDialogService.ShowMessage('Location permission not granted');
        end;
      end)
  else
{$ENDIF}
    LocationSensor1.Active := False;
end;