首次使用Facebook登录登录应用程序，将重定向到应用程序注册页面？
问题描述：
当用户第一次登录到我的应用程序与facebook登录按钮， 我希望它重定向到FB用户的应用程序注册/注册活动（key-in username/password等），当他们再次用FB登录， 应用程序将检查服务器是否存在FB用户Acc？ &跳过FB的注册活动，并重定向到主着陆页活动，首次使用Facebook登录登录应用程序，将重定向到应用程序注册页面？
我的问题在这里是我的代码来检查DB如果FB用户已经注册或不是？
是在：
onActivityResult(int requestCode, int resultCode, Intent data) {}?
我知道的意图做回数据，但不知道如何访问它，因为我不知道额外的按键名称...或者是有另一种方式为拿到它，为实现它？
我已经
我目前正在使用Facebook登录按钮，检查了Facebook的dev的页面，但我迷茫和不已了解它这个
有人可以提供我的代码将如何看起来像一个简单的结构？
UPDATE： 下面是我的FacebookCallback<LoginResult>()样子：
private FacebookCallback<LoginResult> mCallBack = new FacebookCallback<LoginResult>() {
@Override
public void onSuccess(LoginResult loginResult) {
progressDialog.dismiss();
// App code
GraphRequest request = GraphRequest.newMeRequest(
loginResult.getAccessToken(),
new GraphRequest.GraphJSONObjectCallback() {
@Override
public void onCompleted(
JSONObject object,
GraphResponse response) {
Log.e("response: ", response + "");
try {
//=================================================================//
// Create User Code
System.out.println("FB successful login");
user = new User();
//user.facebookID = object.getString("id").toString();
user.userID = object.getString("id").toString();
user.email = object.getString("email").toString();
user.name = object.getString("name").toString();
user.gender = object.getString("gender").toString();
PrefUtils.setCurrentUser(user, MainLoginActivity.this);
//STOP, if NOT Registered
//Function to check if email exist in DB
facebookCheckEmail(user.email);
if(fbresponse.equals("ok")) {
//=================================================================//
// Start MainActivity Code
Intent intent=new Intent(MainLoginActivity.this, MainActivity.class);
startActivity(intent);
Toast.makeText(MainLoginActivity.this, "Welcome " + user.name, Toast.LENGTH_LONG).show();
finish();
} else if(fbresponse.equals("no")){
//=================================================================//
// Pop up Dialog to Register & goto FB Register Activity
AlertDialog.Builder builder = new AlertDialog.Builder(getApplicationContext());
builder.setTitle("You Have Not Yet Registered");
builder.setMessage("You have not yet registered using Facebook, register now?");
builder.setPositiveButton("YES", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// Goto FB Register Activity
dialog.dismiss();
}
});
builder.setNegativeButton("NO", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// Do nothing
dialog.dismiss();
}
});
AlertDialog alert = builder.create();
alert.show();
}
//=================================================================//
// Start MainActivity Code
//Intent intent=new Intent(MainLoginActivity.this, MainActivity.class);
//startActivity(intent);
//Toast.makeText(MainLoginActivity.this, "Welcome " + user.name, Toast.LENGTH_LONG).show();
//finish();
}catch (Exception e){
e.printStackTrace();
System.out.println("FB failed login = " + e.toString());
}
}
});
Bundle parameters = new Bundle();
parameters.putString("fields","id,name,email,gender,birthday");
request.setParameters(parameters);
request.executeAsync();
}
@Override
public void onCancel() {
progressDialog.dismiss();
}
@Override
public void onError(FacebookException e) {
progressDialog.dismiss();
System.out.println("Facebook error " + e.toString());
Toast.makeText(MainLoginActivity.this, "Something goes wrong.." + e.toString(), Toast.LENGTH_LONG).show();
}
};
及以下facebookCheckEmail()功能：
private void facebookCheckEmail(String email) {
fbCheckEmail_params = new HashMap<String, String>();
fbCheckEmail_params.put("Email", email);
final GsonRequest<FbCheckObject> gsonRequest = ApiRequest.gsonFacebookCheckEmailRequest
(
new Response.Listener<FbCheckObject>() {
@Override
public void onResponse(FbCheckObject fbCheckObject) {
try {
System.out.println("Status = " + fbCheckObject.getStatus());
if (new String(fbCheckObject.getStatus()).equals("ok") == true) {
fbresponse = "ok";
} else if(new String(fbCheckObject.getStatus()).equals("no") == true){
fbresponse = "no";
}
} catch (Exception e) {
Log.d("Web Service Error", e.getMessage());
e.printStackTrace();
}
}
}
,
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
// Deal with the error here
}
},
fbCheckEmail_params
);
AppController.getInstance().addToRequestQueue(gsonRequest, TAG);
}
的facebookCheckEmail是GSONRequest，需要一个email参数，将设置一个字符串变量fbresponse到ok或no，我的问题是设置为fbresponse的值在facebookCheckEmail()不更新并获得null当我检查它在FacebookCallback<LoginResult>()
答
可以通过使用callbackmanager
LoginManager.getInstance().registerCallback(mCallbackManager,
new FacebookCallback<LoginResult>() {
@Override
public void onSuccess(LoginResult loginResult) {
Log.i("NIC", "Success Login");
//Call Graph API here to retrieve user's data
//Call to you Backend to check if user is registered, then do your stuff here
}
@Override
public void onCancel() {
Toast.makeText(General_login_menu.this, "Login Cancel", Toast.LENGTH_LONG).show();
Log.i("NIC", "Cancel Login");
}
@Override
public void onError(FacebookException exception) {
Toast.makeText(General_login_menu.this, exception.getMessage(), Toast.LENGTH_LONG).show();
Log.i("NIC", "Error Login");
}
});