facebook login and share dialog not shown in android mobile in unity - facebook

Question

I'm using facebook sdk 7.4 and unity 5.2.2f1 and I want to login into facebook profile and share the game using FB.FeedShare function in android phone. The login works in editor, but not in android phone. when login button is pressed, a dialog window is getting load but it disappears quickly. The share functionality has the same problem.
I'm stucked in this problem for 2 weeks, and I don't know what to do! I'll be so gratefull if anybody can solve it..
public void initFB() {
if (!FB.IsInitialized) {
FB.Init (setInit, onUnityHide);
} else {
isLoggedIn = FB.IsLoggedIn;
}
}
public void setInit() {
if (FB.IsLoggedIn) {
Debug.Log ("u r logged in!");
getProfile();
} else {
Debug.Log ("u r not logged in!");
}
isLoggedIn = FB.IsLoggedIn;
}
private void onUnityHide(bool isShown) {
if (!isShown) {
Time.timeScale = 0;
} else {
Time.timeScale = 1;
}
}
public void FBLogin() {
List<string> perms = new List<string> ();
perms.Add ("public_profile");
FB.LogInWithReadPermissions (perms, authCallBack);
}
public void authCallBack(IResult result) {
if (result.Error != null) {
Debug.Log (result.Error.ToString ());
} else {
if (FB.IsLoggedIn) {
FacebookManager.Instance.isLoggedIn = true;
FacebookManager.Instance.getProfile();
Debug.Log ("you are logged in!");
} else {
Debug.Log ("you are not logged in!");
}
setMenu(FB.IsLoggedIn);
}
}
public void share() {
FB.FeedShare (
string.Empty,
null,
"Hi Title!",
"Hi Caption!",
"Hi Description!",
new System.Uri("http://s3.img7.ir/hPyQA.jpg"),
string.Empty,
shareCall
);
}
public void shareCall(IResult result) {
if (result.Cancelled) {
Debug.Log ("share cancelled!");
} else if (!string.IsNullOrEmpty (result.Error)) {
Debug.Log ("error on share!");
} else if (!string.IsNullOrEmpty (result.RawResult)){
Debug.Log ("success on share!");
}
}