前一篇我们学习了集成FacebookSDK到我们项目工程中,这篇来学习一下如何使用facebook来登录!
1、打开 res/layout/activity_main.xml,在布局中添加一个facebook登录按钮
<LinearLayout xmlns:Android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity" >
<com.facebook.widget.LoginButton
android:id="@+id/login_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginBottom="30dp"
android:layout_marginTop="30dp" />
</LinearLayout>
2、 创建MainFragment 类,并且继承Fragment 类,
重写onCreateView()方法
通过LoginButton设置权限 setReadPermissions() 更多权限访问 #permissions
重写 onSessionStateChange()方法 ,作用:当session状态改变时调用该方法,state.isOpened() 为 true 时,则证明登录成功!
package com.thirdfacebook;
import java.util.Arrays;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.facebook.Session;
import com.facebook.SessionState;
import com.facebook.UiLifecycleHelper;
import com.facebook.widget.LoginButton;
public class MainFragment extends Fragment {
private static final String TAG = "MainFragment";
private UiLifecycleHelper uiHelper;
private Session.StatusCallback callback = new Session.StatusCallback() {
@Override
public void call(Session session, SessionState state,
Exception exception) {
onSessionStateChange(session, state, exception);
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
uiHelper = new UiLifecycleHelper(getActivity(), callback);
uiHelper.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.activity_main, container, false);
LoginButton authButton = (LoginButton) view
.findViewById(R.id.login_button);
authButton.setFragment(this);
authButton.setReadPermissions(Arrays
.asList("email","user_likes", "user_status"));
return view;
}
private void onSessionStateChange(Session session, SessionState state,
Exception exception) {
if (state.isOpened()) {
Log.i(TAG, "Logged in...");
} else if (state.isClosed()) {
Log.i(TAG, "Logged out...");
}
}
@Override
public void onResume() {
super.onResume();
// For scenarios where the main activity is launched and user
// session is not null, the session state change notification
// may not be triggered. Trigger it if it's open/closed.
Session session = Session.getActiveSession();
if (session != null && (session.isOpened() || session.isClosed())) {
onSessionStateChange(session, session.getState(), null);
}
uiHelper.onResume();
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
uiHelper.onActivityResult(requestCode, resultCode, data);
}
@Override
public void onPause() {
super.onPause();
uiHelper.onPause();
}
@Override
public void onDestroy() {
super.onDestroy();
uiHelper.onDestroy();
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
uiHelper.onSaveInstanceState(outState);
}
}