我正在研究一个Android应用程序而且我遇到了一些问题。我创建了一个连接Android应用的应用引擎。后端已部署，我正在向端点添加身份验证。代码编译时没有错误并在我的设备上启动但是当我按下按钮进入注册活动时强制关闭。我检查了Logcat，它说：
无法找到方法 com.Google.api.client.googleapis.extensions.android.GMs.auth.GoogleAccountCredential.newChooseAccountIntent， 由RegistrationActivity.chooseAccount
引用
我该怎么做才能解决这个问题？
PromoterRegistrationActivity
package com.theincrowd;
import java.io.IOException;
import com.google.api.client.extensions.android.http.AndroidHttp;
import com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential;
import com.google.api.client.json.gson.GsonFactory;
import com.theincrowd.promoterendpoint.Promoterendpoint;
import com.theincrowd.promoterendpoint.model.Promoter;
import android.os.AsyncTask;
import android.os.Bundle;
import android.accounts.AccountManager;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class PromoterRegistrationActivity extends Activity {
static final String PREF_ACCOUNT_NAME = "accountName";
static final int REQUEST_ACCOUNT_PICKER = 1;
static final String PREF_AUTH_TOKEN = "authToken";
//credentials
GoogleAccountCredential credential;
//Shared Preferences and preferred user
SharedPreferences settings;
String accountName;
boolean signedIn = false;
Promoterendpoint service;
//text fields and button stuff
EditText fn = (EditText) findViewById(R.id.firstName);
EditText ln = (EditText) findViewById(R.id.lastName);
EditText org = (EditText) findViewById(R.id.editText1);
EditText email = (EditText) findViewById(R.id.editText2);
Button regBut = (Button) findViewById(R.id.regButton);
private String firstName = fn.getText().toString();
private String lastName = ln.getText().toString();
private String organization = org.getText().toString();
private String emailAddress = email.getText().toString();
//this method gets data from the text fields and populates an instance of the Promoter model
protected void CreateNewPromoter(){
Promoter nuPromoter = new Promoter();
nuPromoter.setFirstName(firstName);
nuPromoter.setLastName(lastName);
nuPromoter.setOrganization(organization);
nuPromoter.setEmail(emailAddress);
new CreateNewPromoterTask().execute(nuPromoter);
}
//class writes new promoters to the datastore
private class CreateNewPromoterTask extends AsyncTask<Promoter, Void, Void>{
//
protected Void doInBackground(Promoter... nuPromoters){
try{
service.insertPromoter(nuPromoters[0]).execute();
}catch (IOException e){
e.printStackTrace();
}
return null;
}
}
//Include methods for setSelectedAccountName and the account picker
public void signedIn(View v){
if(!this.signedIn){
chooseAccount();
}else {
forgetAccount();
}
}
//account picker. here lies my problem...
private void chooseAccount() {
startActivityForResult(credential.newChooseAccountIntent(), REQUEST_ACCOUNT_PICKER);
}
private void setAccountName(String accountName) {
SharedPreferences.Editor editor = settings.edit();
editor.putString(PREF_ACCOUNT_NAME, accountName);
editor.commit();
credential.setSelectedAccountName(accountName);
this.accountName = accountName;
}
private void onSignedIn() {
// TODO Auto-generated method stub
this.signedIn = true;
}
private void forgetAccount() {
this.signedIn = false;
SharedPreferences.Editor editor2 = settings.edit();
editor2.remove(PREF_AUTH_TOKEN);
editor2.commit();
}
//end of account selection stuff
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_promoter_registration);
credential = GoogleAccountCredential.usingAudience(this, "server:client_id:694163602530-ims6avatrar9aagbhg6gu7ke0p7458pa.apps.googleusercontent.com");
setAccountName(settings.getString(PREF_ACCOUNT_NAME, null));
Promoterendpoint.Builder builder = new Promoterendpoint.Builder(AndroidHttp.newCompatibleTransport(), new GsonFactory(), credential);
service = builder.build();
if (credential.getSelectedAccountName() != null){
onSignedIn();
}
//Place button here
regBut.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View regBut) {
// TODO Auto-generated method stub
CreateNewPromoter();
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data){
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode) {
case REQUEST_ACCOUNT_PICKER:
if (data != null && data.getExtras() != null) {
String accountName = data.getExtras().getString(AccountManager.KEY_ACCOUNT_NAME);
if (accountName != null) {
setAccountName(accountName);
SharedPreferences.Editor editor = settings.edit();
editor.putString(PREF_ACCOUNT_NAME, accountName);
editor.commit();
onSignedIn();
}
}
}
}
}
logcat的：
05-31 13:28:20.860: D/dalvikvm(12545): GC_FOR_ALLOC freed 69K, 2% free 8886K/8984K, paused 45ms, total 51ms
05-31 13:28:20.883: I/dalvikvm-heap(12545): Grow heap (frag case) to 12.217MB for 3686416-byte allocation
05-31 13:28:20.915: D/dalvikvm(12545): GC_FOR_ALLOC freed <1K, 1% free 12485K/12588K, paused 32ms, total 32ms
05-31 13:28:20.954: D/dalvikvm(12545): GC_CONCURRENT freed <1K, 1% free 12485K/12588K, paused 12ms+1ms, total 41ms
05-31 13:28:21.821: D/libEGL(12545): loaded /vendor/lib/egl/libEGL_POWERVR_SGX540_120.so
05-31 13:28:22.094: D/libEGL(12545): loaded /vendor/lib/egl/libGLESv1_CM_POWERVR_SGX540_120.so
05-31 13:28:22.118: D/libEGL(12545): loaded /vendor/lib/egl/libGLESv2_POWERVR_SGX540_120.so
05-31 13:28:22.250: D/OpenGLRenderer(12545): Enabling debug mode 0
05-31 13:28:27.688: I/dalvikvm(12545): Could not find method com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential.newChooseAccountIntent, referenced from method com.theincrowd.PromoterRegistrationActivity.chooseAccount
05-31 13:28:27.696: W/dalvikvm(12545): VFY: unable to resolve virtual method 47: Lcom/google/api/client/googleapis/extensions/android/gms/auth/GoogleAccountCredential;.newChooseAccountIntent ()Landroid/content/Intent;
05-31 13:28:27.696: D/dalvikvm(12545): VFY: replacing opcode 0x6e at 0x0002
05-31 13:28:27.696: I/dalvikvm(12545): Could not find method com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential.setSelectedAccountName, referenced from method com.theincrowd.PromoterRegistrationActivity.setAccountName
05-31 13:28:27.696: W/dalvikvm(12545): VFY: unable to resolve virtual method 48: Lcom/google/api/client/googleapis/extensions/android/gms/auth/GoogleAccountCredential;.setSelectedAccountName (Ljava/lang/String;)Lcom/google/api/client/googleapis/extensions/android/gms/auth/GoogleAccountCredential;
05-31 13:28:27.696: D/dalvikvm(12545): VFY: replacing opcode 0x6e at 0x0010
05-31 13:28:27.696: W/dalvikvm(12545): Unable to resolve superclass of Lcom/theincrowd/promoterendpoint/model/Promoter; (53)
05-31 13:28:27.696: W/dalvikvm(12545): Link of class 'Lcom/theincrowd/promoterendpoint/model/Promoter;' failed
05-31 13:28:27.696: E/dalvikvm(12545): Could not find class 'com.theincrowd.promoterendpoint.model.Promoter', referenced from method com.theincrowd.PromoterRegistrationActivity.CreateNewPromoter
05-31 13:28:27.696: W/dalvikvm(12545): VFY: unable to resolve new-instance 189 (Lcom/theincrowd/promoterendpoint/model/Promoter;) in Lcom/theincrowd/PromoterRegistrationActivity;
05-31 13:28:27.696: D/dalvikvm(12545): VFY: replacing opcode 0x22 at 0x0000
05-31 13:28:27.696: I/dalvikvm(12545): Could not find method com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential.usingAudience, referenced from method com.theincrowd.PromoterRegistrationActivity.onCreate
05-31 13:28:27.696: W/dalvikvm(12545): VFY: unable to resolve static method 49: Lcom/google/api/client/googleapis/extensions/android/gms/auth/GoogleAccountCredential;.usingAudience (Landroid/content/Context;Ljava/lang/String;)Lcom/google/api/client/googleapis/extensions/android/gms/auth/GoogleAccountCredential;
05-31 13:28:27.696: D/dalvikvm(12545): VFY: replacing opcode 0x71 at 0x000b
05-31 13:28:27.696: W/dalvikvm(12545): Unable to resolve superclass of Lcom/theincrowd/promoterendpoint/model/Promoter; (53)
05-31 13:28:27.696: W/dalvikvm(12545): Link of class 'Lcom/theincrowd/promoterendpoint/model/Promoter;' failed
05-31 13:28:27.696: D/dalvikvm(12545): DexOpt: unable to opt direct call 0x0695 at 0x02 in Lcom/theincrowd/PromoterRegistrationActivity;.CreateNewPromoter
05-31 13:28:27.696: D/dalvikvm(12545): DexOpt: unable to opt direct call 0x004e at 0x25 in Lcom/theincrowd/PromoterRegistrationActivity;.onCreate
05-31 13:28:27.696: W/dalvikvm(12545): Unable to resolve superclass of Lcom/theincrowd/promoterendpoint/Promoterendpoint$Builder; (44)
05-31 13:28:27.696: W/dalvikvm(12545): Link of class 'Lcom/theincrowd/promoterendpoint/Promoterendpoint$Builder;' failed
05-31 13:28:27.704: D/dalvikvm(12545): DexOpt: unable to opt direct call 0x0599 at 0x2a in Lcom/theincrowd/PromoterRegistrationActivity;.onCreate
05-31 13:28:27.704: D/AndroidRuntime(12545): Shutting down VM
05-31 13:28:27.704: W/dalvikvm(12545): threadid=1: thread exiting with uncaught exception (group=0x416bd930)
05-31 13:28:27.766: E/AndroidRuntime(12545): FATAL EXCEPTION: main
05-31 13:28:27.766: E/AndroidRuntime(12545): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.theincrowd/com.theincrowd.PromoterRegistrationActivity}: java.lang.NullPointerException
05-31 13:28:27.766: E/AndroidRuntime(12545): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2106)
05-31 13:28:27.766: E/AndroidRuntime(12545): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
05-31 13:28:27.766: E/AndroidRuntime(12545): at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-31 13:28:27.766: E/AndroidRuntime(12545): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
05-31 13:28:27.766: E/AndroidRuntime(12545): at android.os.Handler.dispatchMessage(Handler.java:99)
05-31 13:28:27.766: E/AndroidRuntime(12545): at android.os.Looper.loop(Looper.java:137)
05-31 13:28:27.766: E/AndroidRuntime(12545): at android.app.ActivityThread.main(ActivityThread.java:5039)
05-31 13:28:27.766: E/AndroidRuntime(12545): at java.lang.reflect.Method.invokeNative(Native Method)
05-31 13:28:27.766: E/AndroidRuntime(12545): at java.lang.reflect.Method.invoke(Method.java:511)
05-31 13:28:27.766: E/AndroidRuntime(12545): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-31 13:28:27.766: E/AndroidRuntime(12545): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-31 13:28:27.766: E/AndroidRuntime(12545): at dalvik.system.NativeStart.main(Native Method)
05-31 13:28:27.766: E/AndroidRuntime(12545): Caused by: java.lang.NullPointerException
05-31 13:28:27.766: E/AndroidRuntime(12545): at android.app.Activity.findViewById(Activity.java:1839)
05-31 13:28:27.766: E/AndroidRuntime(12545): at com.theincrowd.PromoterRegistrationActivity.<init>(PromoterRegistrationActivity.java:41)
05-31 13:28:27.766: E/AndroidRuntime(12545): at java.lang.Class.newInstanceImpl(Native Method)
05-31 13:28:27.766: E/AndroidRuntime(12545): at java.lang.Class.newInstance(Class.java:1319)
05-31 13:28:27.766: E/AndroidRuntime(12545): at android.app.Instrumentation.newActivity(Instrumentation.java:1054)
05-31 13:28:27.766: E/AndroidRuntime(12545): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2097)
05-31 13:28:27.766: E/AndroidRuntime(12545): ... 11 more
05-31 13:36:11.032: I/dalvikvm(13422): Could not find method com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential.newChooseAccountIntent, referenced from method com.theincrowd.PromoterRegistrationActivity.chooseAccount
05-31 13:36:11.032: W/dalvikvm(13422): VFY: unable to resolve virtual method 47: Lcom/google/api/client/googleapis/extensions/android/gms/auth/GoogleAccountCredential;.newChooseAccountIntent ()Landroid/content/Intent;
05-31 13:36:11.032: D/dalvikvm(13422): VFY: replacing opcode 0x6e at 0x0002
05-31 13:36:11.032: I/dalvikvm(13422): Could not find method com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential.setSelectedAccountName, referenced from method com.theincrowd.PromoterRegistrationActivity.setAccountName
05-31 13:36:11.032: W/dalvikvm(13422): VFY: unable to resolve virtual method 48: Lcom/google/api/client/googleapis/extensions/android/gms/auth/GoogleAccountCredential;.setSelectedAccountName (Ljava/lang/String;)Lcom/google/api/client/googleapis/extensions/android/gms/auth/GoogleAccountCredential;
05-31 13:36:11.032: D/dalvikvm(13422): VFY: replacing opcode 0x6e at 0x0010
05-31 13:36:11.040: W/dalvikvm(13422): Unable to resolve superclass of Lcom/theincrowd/promoterendpoint/model/Promoter; (53)
05-31 13:36:11.040: W/dalvikvm(13422): Link of class 'Lcom/theincrowd/promoterendpoint/model/Promoter;' failed
05-31 13:36:11.040: E/dalvikvm(13422): Could not find class 'com.theincrowd.promoterendpoint.model.Promoter', referenced from method com.theincrowd.PromoterRegistrationActivity.CreateNewPromoter
05-31 13:36:11.040: W/dalvikvm(13422): VFY: unable to resolve new-instance 189 (Lcom/theincrowd/promoterendpoint/model/Promoter;) in Lcom/theincrowd/PromoterRegistrationActivity;
05-31 13:36:11.040: D/dalvikvm(13422): VFY: replacing opcode 0x22 at 0x0000
05-31 13:36:11.040: I/dalvikvm(13422): Could not find method com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential.usingAudience, referenced from method com.theincrowd.PromoterRegistrationActivity.onCreate
05-31 13:36:11.040: W/dalvikvm(13422): VFY: unable to resolve static method 49: Lcom/google/api/client/googleapis/extensions/android/gms/auth/GoogleAccountCredential;.usingAudience (Landroid/content/Context;Ljava/lang/String;)Lcom/google/api/client/googleapis/extensions/android/gms/auth/GoogleAccountCredential;
05-31 13:36:11.040: D/dalvikvm(13422): VFY: replacing opcode 0x71 at 0x000b
05-31 13:36:11.040: W/dalvikvm(13422): Unable to resolve superclass of Lcom/theincrowd/promoterendpoint/model/Promoter; (53)
05-31 13:36:11.040: W/dalvikvm(13422): Link of class 'Lcom/theincrowd/promoterendpoint/model/Promoter;' failed
05-31 13:36:11.040: D/dalvikvm(13422): DexOpt: unable to opt direct call 0x0695 at 0x02 in Lcom/theincrowd/PromoterRegistrationActivity;.CreateNewPromoter
05-31 13:36:11.047: D/dalvikvm(13422): DexOpt: unable to opt direct call 0x004e at 0x25 in Lcom/theincrowd/PromoterRegistrationActivity;.onCreate
05-31 13:36:11.047: W/dalvikvm(13422): Unable to resolve superclass of Lcom/theincrowd/promoterendpoint/Promoterendpoint$Builder; (44)
05-31 13:36:11.047: W/dalvikvm(13422): Link of class 'Lcom/theincrowd/promoterendpoint/Promoterendpoint$Builder;' failed
05-31 13:36:11.047: D/dalvikvm(13422): DexOpt: unable to opt direct call 0x0599 at 0x2a in Lcom/theincrowd/PromoterRegistrationActivity;.onCreate
05-31 13:36:11.047: D/AndroidRuntime(13422): Shutting down VM
05-31 13:36:11.047: W/dalvikvm(13422): threadid=1: thread exiting with uncaught exception (group=0x416bd930)
05-31 13:36:11.063: E/AndroidRuntime(13422): FATAL EXCEPTION: main
05-31 13:36:11.063: E/AndroidRuntime(13422): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.theincrowd/com.theincrowd.PromoterRegistrationActivity}: java.lang.NullPointerException
05-31 13:36:11.063: E/AndroidRuntime(13422): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2106)
05-31 13:36:11.063: E/AndroidRuntime(13422): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
05-31 13:36:11.063: E/AndroidRuntime(13422): at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-31 13:36:11.063: E/AndroidRuntime(13422): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
05-31 13:36:11.063: E/AndroidRuntime(13422): at android.os.Handler.dispatchMessage(Handler.java:99)
05-31 13:36:11.063: E/AndroidRuntime(13422): at android.os.Looper.loop(Looper.java:137)
05-31 13:36:11.063: E/AndroidRuntime(13422): at android.app.ActivityThread.main(ActivityThread.java:5039)
05-31 13:36:11.063: E/AndroidRuntime(13422): at java.lang.reflect.Method.invokeNative(Native Method)
05-31 13:36:11.063: E/AndroidRuntime(13422): at java.lang.reflect.Method.invoke(Method.java:511)
05-31 13:36:11.063: E/AndroidRuntime(13422): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-31 13:36:11.063: E/AndroidRuntime(13422): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-31 13:36:11.063: E/AndroidRuntime(13422): at dalvik.system.NativeStart.main(Native Method)
05-31 13:36:11.063: E/AndroidRuntime(13422): Caused by: java.lang.NullPointerException
05-31 13:36:11.063: E/AndroidRuntime(13422): at android.app.Activity.findViewById(Activity.java:1839)
05-31 13:36:11.063: E/AndroidRuntime(13422): at com.theincrowd.PromoterRegistrationActivity.<init>(PromoterRegistrationActivity.java:41)
05-31 13:36:11.063: E/AndroidRuntime(13422): at java.lang.Class.newInstanceImpl(Native Method)
05-31 13:36:11.063: E/AndroidRuntime(13422): at java.lang.Class.newInstance(Class.java:1319)
05-31 13:36:11.063: E/AndroidRuntime(13422): at android.app.Instrumentation.newActivity(Instrumentation.java:1054)
05-31 13:36:11.063: E/AndroidRuntime(13422): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2097)
05-31 13:36:11.063: E/AndroidRuntime(13422): ... 11 more
05-31 13:36:13.407: I/Process(13422): Sending signal. PID: 13422 SIG: 9
我希望这会有所帮助......
编辑：添加清单文件。
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="17" />
<permission
android:name="com.theincrowd.permission.C2D_MESSAGE"
android:protectionLevel="signature" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="com.theincrowd.permission.C2D_MESSAGE" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.USE_CREDENTIALS" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.GET_ACCOUNTS"/>
<uses-permission android:name="android.permission.USE_CREDENTIALS"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@android:style/Theme.WithActionBar" >
<activity
android:name="com.theincrowd.MainActivity"
android:label="@string/app_name"
android:theme="@android:style/Theme.NoTitleBar" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name="com.theincrowd.GCMIntentService" />
<receiver
android:name="com.google.android.gcm.GCMBroadcastReceiver"
android:permission="com.google.android.c2dm.permission.SEND" >
<intent-filter>
<action android:name="com.google.android.c2dm.intent.RECEIVE" />
<category android:name="com.theincrowd" />
</intent-filter>
<intent-filter>
<action android:name="com.google.android.c2dm.intent.REGISTRATION" />
<category android:name="com.theincrowd" />
</intent-filter>
</receiver>
<activity
android:name="com.theincrowd.RegisterActivity"
android:launchMode="singleTop" />
<activity
android:name="com.theincrowd.PromoForkActivity"
android:label="@string/title_activity_promo_fork" >
</activity>
<activity
android:name="com.theincrowd.PromoterRegistrationActivity"
android:label="@string/title_activity_promoter_registration" >
</activity>
<activity
android:name="com.theincrowd.PartyGoerDashActivity"
android:label="@string/title_activity_party_goer_dash" >
</activity>
<activity
android:name="com.theincrowd.PartyListTabs"
android:label="@string/title_activity_party_list_tabs" >
</activity>
</application>
答案 0 :(得分：0)
所有这些行必须采用onCreate方法：
提示：有人已告诉您按钮的位置。请参阅代码中的//Place button here。
protected void onCreate(Bundle savedInstanceState) {
...
//text fields and button stuff [FROM HERE]
EditText fn = (EditText) findViewById(R.id.firstName);
EditText ln = (EditText) findViewById(R.id.lastName);
EditText org = (EditText) findViewById(R.id.editText1);
EditText email = (EditText) findViewById(R.id.editText2);
Button regBut = (Button) findViewById(R.id.regButton);
对于以下行，您可以保留这样的声明：
private String firstName;
private String lastName;
private String organization;
private String emailAddress;
然后再次在onCreate中，在您将观看次数转换为EditText之后，您可以按照以下方式阅读其值：
firstName = fn.getText().toString();
lastName = ln.getText().toString();
organization = org.getText().toString();
emailAddress = email.getText().toString();