我的问题有点像这些只是......第一个和第二个问题。我已经尝试了这些帖子上给出的所有内容,但没有任何缓解。
所以我使用android-simple-facebook 库来创建一个 facebook 登录。这是我的 LoginActivity.java
public class LoginActivity extends Activity {
private Button mButtonLogin;
private SimpleFacebook mSimpleFacebook;
protected static final String TAG = LoginActivity.class.getName();
@Override
protected void onCreate(Bundle savedInstanceState) {
mSimpleFacebook = SimpleFacebook.getInstance();
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
mButtonLogin = (Button) findViewById(R.id.button_login);
setLogin();
}
public void setLogin() {
final OnLoginListener onLoginListener = new OnLoginListener() {
@Override
public void onLogin() {
Log.i(TAG, "Logged in");
}
};
mButtonLogin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
mSimpleFacebook.login(onLoginListener);
}
});
}
@Override
public void onResume() {
super.onResume();
// mSimpleFacebook = SimpleFacebook.getInstance();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
mSimpleFacebook.onActivityResult(this, requestCode, resultCode, data);
super.onActivityResult(requestCode, resultCode, data);
}
}
但是,只要我单击登录按钮,应用程序就会崩溃并出现 NullPointerException。这是 LogCat
09-21 15:54:40.109: E/AndroidRuntime(21895): FATAL EXCEPTION: main
09-21 15:54:40.109: E/AndroidRuntime(21895): Process: www.kb.com, PID: 21895
09-21 15:54:40.109: E/AndroidRuntime(21895): java.lang.NullPointerException
09-21 15:54:40.109: E/AndroidRuntime(21895): at www.kb.com.LoginActivity$2.onClick(LoginActivity.java:81)
09-21 15:54:40.109: E/AndroidRuntime(21895): at android.view.View.performClick(View.java:4438)
09-21 15:54:40.109: E/AndroidRuntime(21895): at android.view.View$PerformClick.run(View.java:18422)
09-21 15:54:40.109: E/AndroidRuntime(21895): at android.os.Handler.handleCallback(Handler.java:733)
09-21 15:54:40.109: E/AndroidRuntime(21895): at android.os.Handler.dispatchMessage(Handler.java:95)
09-21 15:54:40.109: E/AndroidRuntime(21895): at android.os.Looper.loop(Looper.java:136)
09-21 15:54:40.109: E/AndroidRuntime(21895): at android.app.ActivityThread.main(ActivityThread.java:5001)
09-21 15:54:40.109: E/AndroidRuntime(21895): at java.lang.reflect.Method.invokeNative(Native Method)
09-21 15:54:40.109: E/AndroidRuntime(21895): at java.lang.reflect.Method.invoke(Method.java:515)
09-21 15:54:40.109: E/AndroidRuntime(21895): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
09-21 15:54:40.109: E/AndroidRuntime(21895): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
09-21 15:54:40.109: E/AndroidRuntime(21895): at dalvik.system.NativeStart.main(Native Method)