标签：play 版本 npe length string oca dev use tostring
安卓蓝牙动态权限
安卓7.0及以下版本
procedure TForm6.FormCreate(Sender: TObject);
begin
{$IFDEF ANDROID}
FLocationPermission := JStringToString(TJManifest_permission.JavaClass.ACCESS_COARSE_LOCATION);
{$ENDIF}
end;
上述代码里面用到的 JStringToString 要 Uses Androidapi.Helpers;
上述代码中还有一个 DisplayRationale 也是一个函数：
procedure TForm6.DisplayRationale(Sender: TObject; const APermissions: TArray<string>; const APostRationaleProc: TProc);
begin
TDialogService.ShowMessage(‘We need to be given permission to discover BLE devices‘,
procedure(const AResult: TModalResult)
begin
APostRationaleProc;
end)
end;
在 RequestPermissionsResult 这个函数里面，判断是否通过权限，如果通过，才去调用蓝牙的方法。
procedure TForm6.RequestPermissionsResult(Sender: TObject; const APermissions: TArray<string>; const AGrantResults: TArray<TPermissionStatus>);
begin
// 1 permissions involved: ACCESS_COARSE_LOCATION
if (Length(AGrantResults) = 1) and (AGrantResults[0] = TPermissionStatus.Granted) then
StartBLEDiscovery
else
TDialogService.ShowMessage(‘Cannot start BLE scan as the permission has not been granted‘);
end;
标签：play 版本 npe length string oca dev use tostring
原文地址：https://www.cnblogs.com/hnxxcxg/p/12114403.html
