当用户点击MainActivity的链接时，我有一个问题切换活动，应用程序将关闭，我不确定我是否有项目结构的问题或正确声明类和扩展。 / p>
基本上我所做的是尝试将网站上提供的Firebase示例项目实现到我的应用程序中的一个活动中，以便有一种方法让成员登录，我将提供的初始代码条带化{{3}并在我的第二个活动窗口中实现它，链接中的代码用于MainActivity，我希望它像LoginFragment（只是一个名字）没有使用片段。
因此，在最小化代码（删除谷歌，脸书等）选项后，我最终得到了这个：
package net.we4x4.we4x4;
import android.app.AlertDialog;
import android.app.Application;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import com.firebase.client.AuthData;
import com.firebase.client.Firebase;
import com.firebase.client.FirebaseError;
import java.util.HashMap;
import java.util.Map;
public class LoginFragment extends AppCompatActivity{
private static final String TAG = MainActivity.class.getSimpleName();
/* *************************************
* GENERAL *
***************************************/
/* TextView that is used to display information about the logged in user */
private TextView mLoggedInStatusTextView;
/* A dialog that is presented until the Firebase authentication finished. */
private ProgressDialog mAuthProgressDialog;
/* A reference to the Firebase */
private Firebase mFirebaseRef;
/* Data from the authenticated user */
private AuthData mAuthData;
/* Listener for Firebase session changes */
private Firebase.AuthStateListener mAuthStateListener;
/* *************************************
* PASSWORD *
***************************************/
private Button mPasswordLoginButton;
/* *************************************
* ANONYMOUSLY *
***************************************/
private Button mAnonymousLoginButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
/* Load the view and display it */
setContentView(R.layout.activity_main);
/* *************************************
* PASSWORD *
***************************************/
mPasswordLoginButton = (Button) findViewById(R.id.login_with_password);
mPasswordLoginButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
loginWithPassword();
}
});
/* *************************************
* ANONYMOUSLY *
***************************************/
/* Load and setup the anonymous login button */
mAnonymousLoginButton = (Button) findViewById(R.id.login_anonymously);
mAnonymousLoginButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
loginAnonymously();
}
});
/* *************************************
* GENERAL *
***************************************/
mLoggedInStatusTextView = (TextView) findViewById(R.id.login_status);
/* Create the Firebase ref that is used for all authentication with Firebase */
mFirebaseRef = new Firebase(getResources().getString(R.string.firebase_url));
/* Setup the progress dialog that is displayed later when authenticating with Firebase */
mAuthProgressDialog = new ProgressDialog(this);
mAuthProgressDialog.setTitle("Loading");
mAuthProgressDialog.setMessage("Authenticating with Firebase...");
mAuthProgressDialog.setCancelable(false);
mAuthProgressDialog.show();
mAuthStateListener = new Firebase.AuthStateListener() {
@Override
public void onAuthStateChanged(AuthData authData) {
mAuthProgressDialog.hide();
setAuthenticatedUser(authData);
}
};
/* Check if the user is authenticated with Firebase already. If this is the case we can set the authenticated
* user and hide hide any login buttons */
mFirebaseRef.addAuthStateListener(mAuthStateListener);
}
@Override
protected void onDestroy() {
super.onDestroy();
// if changing configurations, stop tracking firebase session.
mFirebaseRef.removeAuthStateListener(mAuthStateListener);
}
/**
* This method fires when any startActivityForResult finishes. The requestCode maps to
* the value passed into startActivityForResult.
*/
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
Map<String, String> options = new HashMap<String, String>();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
/* If a user is currently authenticated, display a logout menu */
if (this.mAuthData != null) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
} else {
return false;
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_logout) {
logout();
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* Unauthenticate from Firebase and from providers where necessary.
*/
private void logout() {
if (this.mAuthData != null) {
/* logout of Firebase */
mFirebaseRef.unauth();
}
/* Update authenticated user and show login buttons */
setAuthenticatedUser(null);
}
/**
* This method will attempt to authenticate a user to firebase given an oauth_token (and other
* necessary parameters depending on the provider)
*/
private void authWithFirebase(final String provider, Map<String, String> options) {
if (options.containsKey("error")) {
showErrorDialog(options.get("error"));
} else {
mAuthProgressDialog.show();
if (provider.equals("twitter")) {
// if the provider is twitter, we pust pass in additional options, so use the options endpoint
mFirebaseRef.authWithOAuthToken(provider, options, new AuthResultHandler(provider));
} else {
// if the provider is not twitter, we just need to pass in the oauth_token
mFirebaseRef.authWithOAuthToken(provider, options.get("oauth_token"), new AuthResultHandler(provider));
}
}
}
/**
* Once a user is logged in, take the mAuthData provided from Firebase and "use" it.
*/
private void setAuthenticatedUser(AuthData authData) {
if (authData != null) {
/* Hide all the login buttons */
mPasswordLoginButton.setVisibility(View.GONE);
mAnonymousLoginButton.setVisibility(View.GONE);
mLoggedInStatusTextView.setVisibility(View.VISIBLE);
/* show a provider specific status text */
String name = null;
if (authData.getProvider().equals("facebook")
|| authData.getProvider().equals("google")
|| authData.getProvider().equals("twitter")) {
name = (String) authData.getProviderData().get("displayName");
} else if (authData.getProvider().equals("anonymous")
|| authData.getProvider().equals("password")) {
name = authData.getUid();
} else {
Log.e(TAG, "Invalid provider: " + authData.getProvider());
}
if (name != null) {
mLoggedInStatusTextView.setText("Logged in as " + name + " (" + authData.getProvider() + ")");
}
} else {
/* No authenticated user show all the login buttons */
mPasswordLoginButton.setVisibility(View.VISIBLE);
mAnonymousLoginButton.setVisibility(View.VISIBLE);
mLoggedInStatusTextView.setVisibility(View.GONE);
}
this.mAuthData = authData;
/* invalidate options menu to hide/show the logout button */
supportInvalidateOptionsMenu();
}
/**
* Show errors to users
*/
private void showErrorDialog(String message) {
new AlertDialog.Builder(this)
.setTitle("Error")
.setMessage(message)
.setPositiveButton(android.R.string.ok, null)
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
}
/**
* Utility class for authentication results
*/
private class AuthResultHandler implements Firebase.AuthResultHandler {
private final String provider;
public AuthResultHandler(String provider) {
this.provider = provider;
}
@Override
public void onAuthenticated(AuthData authData) {
mAuthProgressDialog.hide();
Log.i(TAG, provider + " auth successful");
setAuthenticatedUser(authData);
}
@Override
public void onAuthenticationError(FirebaseError firebaseError) {
mAuthProgressDialog.hide();
showErrorDialog(firebaseError.toString());
}
}
/* ************************************
* PASSWORD *
**************************************
*/
public void loginWithPassword() {
mAuthProgressDialog.show();
mFirebaseRef.authWithPassword("test@firebaseuser.com", "test1234", new AuthResultHandler("password"));
}
/* ************************************
* ANONYMOUSLY *
**************************************
*/
private void loginAnonymously() {
mAuthProgressDialog.show();
mFirebaseRef.authAnonymously(new AuthResultHandler("anonymous"));
}
public void switchToRegister(View v) {
Intent Register = new Intent(this, Register.class);
startActivity(Register);
}
}
正如你们所看到的那样我宣称这个类是公共的并且扩展了AppCompatActivity（不确定我刚刚从另一个教程中学到了什么）我还尝试从Application扩展它，我认为它可以工作，但是列出的代码中出现了各种错误：
宣言中的：
<?xml version="1.0" encoding="utf-8"?>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.USE_CREDENTIALS" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme" >
<activity
android:name="net.we4x4.we4x4.MainActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".LoginFragment">
</activity>
<activity android:name=".Register">
</activity>
<!-- ATTENTION: This was auto-generated to add Google Play services to your project for
App Indexing. See https://g.co/AppIndexing/AndroidStudio for more information. -->
<meta-data
android:name="com.google.android.gms.version"
android:value="@integer/google_play_services_version" />
</application>
在.LoginFragment下的第27行，它说它不能分配给android.app.activity？
然后在代码本身LoginFragment：
我得到了这些我无法解决的错误： 第58行 - setContentView无法解决此方法？ 的setContentView（R.layout.fragment_login）;
第63行findViewById也无法解决此方法？
mPasswordLoginButton = (Button) findViewById(R.id.login_with_password);
相同的匿名选项第75行 mAnonymousLoginButton =（Button）findViewById（R.id.login_anonymously）;
与第86行findViewById相同的问题？ mLoggedInStatusTextView =（TextView）findViewById（R.id.login_status）;
显然我需要创建findViewById mehtod如果我想扩展Application，但我没有继续这个，因为我不知道我是否应该从Application扩展，考虑到我在代码中没有得到任何这些错误从MainActivity或AppCompatActivity扩展
我上线114也无法解决此方法 super.onDestroy（）;
还有其他几个......？
所以我不确定如何解决这个问题？我应该扩展应用程序并解决这些错误（以及如何解决这些错误）或保持MainActivity或AppCompatActivity的扩展？它在代码中不包含任何错误，但无法正常切换活动：
我的MainActivity是：
package net.we4x4.we4x4;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.MediaController;
import android.widget.VideoView;
import com.firebase.client.Firebase;
public class MainActivity extends AppCompatActivity {
public static final String VID_URL = "http://res.cloudinary.com/wi4x4/video/upload/v1457270321/bolivia_njb6r0.mp4";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
Firebase.setAndroidContext(this);
VideoView vid = (VideoView)findViewById(R. id.VidClip);
Uri video = Uri.parse(VID_URL);
vid.setMediaController(new MediaController(this));
vid.setVideoURI(video);
vid.requestFocus();
}
}
public void switchToLoginFragment(View v) {
Intent LoginFragment = new Intent(this, LoginFragment.class);
startActivity(LoginFragment);
}
public void switchToRegister(View v) {
Intent Register = new Intent(this, Register.class);
startActivity(Register);
}
}
，错误日志为：
6:16:51 PM AssertionError: Wrong element range PsiJavaFile:LoginFragment.java; committed=true
android monitor：
03-07 18:19:52.512 21730-21730/net.we4x4.we4x4 E/AndroidRuntime: FATAL EXCEPTION: main
Process: net.we4x4.we4x4, PID: 21730
java.lang.RuntimeException: Unable to start activity ComponentInfo{net.we4x4.we4x4/net.we4x4.we4x4.LoginFragment}: java.lang.IllegalStateException: For a custom firebase host you must first set your authentication server before using authentication features!
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2429)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2493)
at android.app.ActivityThread.access$800(ActivityThread.java:166)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1283)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5584)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalStateException: For a custom firebase host you must first set your authentication server before using authentication features!
at com.firebase.client.authentication.AuthenticationManager.checkServerSettings(AuthenticationManager.java:221)
at com.firebase.client.authentication.AuthenticationManager.addAuthStateListener(AuthenticationManager.java:625)
at com.firebase.client.Firebase.addAuthStateListener(Firebase.java:555)
at net.we4x4.we4x4.LoginFragment.onCreate(LoginFragment.java:107)
at android.app.Activity.performCreate(Activity.java:5447)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2393)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2493)
at android.app.ActivityThread.access$800(ActivityThread.java:166)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1283)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5584)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084)
at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：1)
此例外：
java.lang.RuntimeException：无法启动活动ComponentInfo {net.we4x4.we4x4 / net.we4x4.we4x4.LoginFragment}：java.lang.IllegalStateException：对于自定义firebase主机，您必须先使用身份验证服务器身份验证功能！
来自这条线：
mFirebaseRef =新的Firebase（getResources（）。getString（R.string.firebase_url））;
原因是firebase_url的格式不是https://yours.firebaseio.com。