1.我可以获得授权码 . 2.我能够兑换令牌的授权码 . 3.我可以通过打开来发现OneDrive for Business资源URI
浏览器中的服务 endpoints 链接，并在另一个选项卡中签名 . 4.向OneDrive API发出请求（即使我已成功完成上述步骤，也会遇到未经授权的异常 .

为访问令牌兑换刷新令牌以调用OneDrive API

edt_OneDrive_AuthCode := '';
edt_OneDrive_AccessToken := '';
edt_OneDrive_RefreshToken := '';
edt_OneDrive_ClientID:='*************************************';
edt_AzureTenant_ID:='****************************' ;


//edt_OneDrive_RedirectURI:= 'https://login.live.com/oauth20_desktop.srf'; // ??

edt_OneDrive_RedirectURI:= 'https://login.microsoftonline.com/';
edt_OneDrive_Resource:='https://api.office.com/discovery/';

LURL := 'https://login.microsoftonline.com/common/oauth2/authorize';
LURL := LURL + '?response_type=' + URIEncode('code');
LURL := LURL + '&client_id=' + URIEncode(edt_OneDrive_ClientID);
LURL := LURL + '&redirect_uri=' + URIEncode(edt_OneDrive_RedirectURI);
//LURL := LURL + '&resource=' + URIEncode(edt_OneDrive_Resource);
//https://login.microsoftonline.com/common/oauth2/authorize?response_type=code&client_id={client_id}&redirect_uri={redirect_uri}

///1.Log in and get an authorization code
 wv := Tfrm_OAuthWebForm.Create(self);
try
  wv.OnTitleChanged := self.OAuth2_OneDrive_BrowserTitleChanged;
  wv.ShowModalWithURL(LURL);
finally
  wv.Release;
end;


//Step 2: Redeem the authorization code for tokens
RESTClient:=TRESTClient.Create(nil);
RESTClient.BaseURL := 'https://login.microsoftonline.com/********-****-****-****-************/oauth2/token';

RESTRequest := TRESTRequest.Create(nil);
RESTRequest.Method := TRESTRequestMethod.rmPOST;
RESTRequest.Client:=   RESTClient;
RESTRequest.Params.AddItem('client_id', edt_OneDrive_ClientID, TRESTRequestParameterKind.pkGETorPOST);
RESTRequest.Params.AddItem('redirect_uri',edt_OneDrive_RedirectURI , TRESTRequestParameterKind.pkGETorPOST);
RESTRequest.Params.AddItem('grant_type', 'authorization_code', TRESTRequestParameterKind.pkGETorPOST);
RESTRequest.Params.AddItem('resource', 'https://api.office.com/discovery/', TRESTRequestParameterKind.pkGETorPOST);
RESTRequest.Params.AddItem('code', edt_OneDrive_AuthCode, TRESTRequestParameterKind.pkGETorPOST);
RESTRequest.Params.AddItem('prompt', 'admin_consent', TRESTRequestParameterKind.pkGETorPOST);
RESTRequest.Execute;


OAuth2_OneDrive:=TOAuth2Authenticator.Create(nil);

if RESTRequest.Response.GetSimpleValue('access_token', LToken) then
     OAuth2_OneDrive.AccessToken := LToken;
if RESTRequest.Response.GetSimpleValue('refresh_token', LToken) then
     OAuth2_OneDrive.RefreshToken := LToken;

 //STEP 3:Discover the OneDrive for Business resource URI
 //GET https://api.office.com/discovery/v2.0/me/services
 //Authorization: Bearer {access_token}

{ RESTRequest.ClearBody;
 RESTRequest.Params.Clear;

 RESTClient:=TRESTClient.Create(nil);
 RESTClient.BaseURL := 'https://api.office.com/discovery/v2.0/me/services';

 RESTRequest := TRESTRequest.Create(nil);
 RESTRequest.Method := TRESTRequestMethod.rmGET;
 RESTRequest.Client:=   RESTClient;
 RESTRequest.AddAuthParameter('Authorization', 'Bearer ' + OAuth2_OneDrive.AccessToken, TRESTRequestParameterKind.pkHTTPHEADER,[TRESTRequestParameterOption.poDoNotEncode]);
 RESTRequest.Execute; }

 //Step 4. Redeem refresh token for an access token to call OneDrive API
 RESTRequest.ClearBody;
 RESTRequest.Params.Clear;

 RESTClient:=TRESTClient.Create(nil);
 RESTClient.BaseURL := 'https://login.microsoftonline.com/********-****-****-****-************/oauth2/token';

 RESTRequest := TRESTRequest.Create(nil);
 RESTRequest.Method := TRESTRequestMethod.rmPOST;
 RESTRequest.Client:=   RESTClient;
 RESTRequest.Params.AddItem('client_id', edt_OneDrive_ClientID, TRESTRequestParameterKind.pkGETorPOST);
 RESTRequest.Params.AddItem('grant_type', 'refresh_token', TRESTRequestParameterKind.pkGETorPOST);
 //RESTRequest.Params.AddItem('resource', 'https://api.office.com/discovery/', TRESTRequestParameterKind.pkGETorPOST);
 RESTRequest.Params.AddItem('resource', 'https://comp14602-my.sharepoint.com/', TRESTRequestParameterKind.pkGETorPOST);

 RESTRequest.Params.AddItem('refresh_token',OAuth2_OneDrive.RefreshToken , TRESTRequestParameterKind.pkGETorPOST);
 RESTRequest.Execute;


 OAuth2_OneDrive:=TOAuth2Authenticator.Create(nil);

 if RESTRequest.Response.GetSimpleValue('access_token', LToken) then
     OAuth2_OneDrive.AccessToken := LToken;
 if RESTRequest.Response.GetSimpleValue('refresh_token', LToken) then
     OAuth2_OneDrive.RefreshToken := LToken;
//Step 5. Make a request to the OneDrive API

 RESTRequest.ClearBody;
 RESTRequest.Params.Clear;

 RESTClient:=TRESTClient.Create(nil);

 RESTClient.BaseURL :='https://{tenant name here}-my.sharepoint.com/_api/v2.0/me/drive';



 RESTRequest := TRESTRequest.Create(nil);
 RESTRequest.Method := TRESTRequestMethod.rmGET;
 RESTRequest.Client := RESTClient;


 RESTRequest.AddAuthParameter('Authorization', 'Bearer ' + OAuth2_OneDrive.AccessToken, TRESTRequestParameterKind.pkHTTPHEADER,[TRESTRequestParameterOption.poDoNotEncode]);

 RESTRequest.Execute;//Here am getting unauthorized exception
delphi onedrive