Android 应用无法启动 Activity 组件

Question

我是一名新的 Android 程序员，我真的不知道如何解决我的问题。我的应用名称是 musteatandgo。我在模拟器上安装了 musteatandgo.apk，有时 eclipse 找不到设备，有时我会在模拟器上看到“应用程序未安装”或“应用程序(进程 com.musteatandgo)意外停止。”

12-01 14:25:48.338: D/AndroidRuntime(284): Shutting down VM
12-01 14:25:48.348: W/dalvikvm(284): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
12-01 14:25:48.368: E/AndroidRuntime(284): FATAL EXCEPTION: main
12-01 14:25:48.368: E/AndroidRuntime(284): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.musteatandgo/com.musteatandgo.MainActivity}: java.lang.NullPointerException: Argument 'applicationId' cannot be null
12-01 14:25:48.368: E/AndroidRuntime(284):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)

list

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.musteatandgo"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.musteatandgo.MainActivity$start"
            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= ".Main">
            </activity>
        <meta-data android:name="com.facebook.sdk.ApplicationId" android:value="1390160477887243"/>
        <activity android:name="com.facebook.LoginActivity" android:label="MustEatandGo"></activity>
    </application>

</manifest>

主要 Activity

package com.musteatandgo;


import android.os.Bundle;
import android.app.Activity;
import com.facebook.*;
import com.facebook.model.*;
import android.widget.TextView;
import android.content.Intent;


public class MainActivity extends Activity {

      @Override
      public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // start Facebook Login
        Session.openActiveSession(this, true, new Session.StatusCallback() {

          // callback when session changes state
          @Override
          public void call(Session session, SessionState state, Exception exception) {
            if (session.isOpened()) {

              // make request to the /me API
              Request.newMeRequest(session, new Request.GraphUserCallback() {

                // callback after Graph API response with user object
                @Override
                public void onCompleted(GraphUser user, Response response) {
                  if (user != null) {
                    TextView welcome = (TextView) findViewById(R.id.welcome);
                    welcome.setText("Hello " + user.getName() + "!");
                  }
                }
              });
            }
          }
        });
      }

      @Override
      public void onActivityResult(int requestCode, int resultCode, Intent data) {
          super.onActivityResult(requestCode, resultCode, data);
          Session.getActiveSession().onActivityResult(this, requestCode, resultCode, data);
      }


}

Answer 1

在您的 MANIFEST com.musteatandgo.MainActivity$start 中将其更改为 .MainActivity