当我试图启动我的App In Genymotion时，我收到以下错误：
09-08 07:03:12.697: E/AndroidRuntime(2291): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.waddapp/com.example.waddapp.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.example.waddapp.MainActivity" on path: DexPathList[[zip file "/data/app/com.example.waddapp-1/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
09-08 07:03:12.697: E/AndroidRuntime(2291): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2236)
09-08 07:03:12.697: E/AndroidRuntime(2291): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
09-08 07:03:12.697: E/AndroidRuntime(2291): at android.app.ActivityThread.access$800(ActivityThread.java:151)
09-08 07:03:12.697: E/AndroidRuntime(2291): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
09-08 07:03:12.697: E/AndroidRuntime(2291): at android.os.Handler.dispatchMessage(Handler.java:102)
09-08 07:03:12.697: E/AndroidRuntime(2291): at android.os.Looper.loop(Looper.java:135)
09-08 07:03:12.697: E/AndroidRuntime(2291): at android.app.ActivityThread.main(ActivityThread.java:5254)
09-08 07:03:12.697: E/AndroidRuntime(2291): at java.lang.reflect.Method.invoke(Native Method)
09-08 07:03:12.697: E/AndroidRuntime(2291): at java.lang.reflect.Method.invoke(Method.java:372)
09-08 07:03:12.697: E/AndroidRuntime(2291): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
09-08 07:03:12.697: E/AndroidRuntime(2291): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
09-08 07:03:12.697: E/AndroidRuntime(2291): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.waddapp.MainActivity" on path: DexPathList[[zip file "/data/app/com.example.waddapp-1/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
09-08 07:03:12.697: E/AndroidRuntime(2291): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
09-08 07:03:12.697: E/AndroidRuntime(2291): at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
09-08 07:03:12.697: E/AndroidRuntime(2291): at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
09-08 07:03:12.697: E/AndroidRuntime(2291): at android.app.Instrumentation.newActivity(Instrumentation.java:1066)
09-08 07:03:12.697: E/AndroidRuntime(2291): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2226)
09-08 07:03:12.697: E/AndroidRuntime(2291): ... 10 more
09-08 07:03:12.697: E/AndroidRuntime(2291): Suppressed: java.lang.NoClassDefFoundError: com.example.waddapp.MainActivity
09-08 07:03:12.697: E/AndroidRuntime(2291): at dalvik.system.DexFile.defineClassNative(Native Method)
09-08 07:03:12.697: E/AndroidRuntime(2291): at dalvik.system.DexFile.defineClass(DexFile.java:226)
09-08 07:03:12.697: E/AndroidRuntime(2291): at dalvik.system.DexFile.loadClassBinaryName(DexFile.java:219)
09-08 07:03:12.697: E/AndroidRuntime(2291): at dalvik.system.DexPathList.findClass(DexPathList.java:321)
09-08 07:03:12.697: E/AndroidRuntime(2291): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:54)
09-08 07:03:12.697: E/AndroidRuntime(2291): ... 14 more
09-08 07:03:12.697: E/AndroidRuntime(2291): Suppressed: java.lang.ClassNotFoundException: com.example.waddapp.MainActivity
09-08 07:03:12.697: E/AndroidRuntime(2291): at java.lang.Class.classForName(Native Method)
09-08 07:03:12.697: E/AndroidRuntime(2291): at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
09-08 07:03:12.697: E/AndroidRuntime(2291): at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
09-08 07:03:12.697: E/AndroidRuntime(2291): at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
09-08 07:03:12.697: E/AndroidRuntime(2291): ... 13 more
09-08 07:03:12.697: E/AndroidRuntime(2291): Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available
为什么找不到我的班级？
这是我的代码：
package com.example.waddapp;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.View;
import android.widget.TextView;
import com.facebook.Request;
import com.facebook.Response;
import com.facebook.Session;
import com.facebook.SessionState;
import com.facebook.UiLifecycleHelper;
import com.facebook.model.GraphUser;
public class MainActivity extends ActionBarActivity {
// Create, automatically open (if applicable), save, and restore the
// Active Session in a way that is similar to Android UI lifecycles.
private UiLifecycleHelper uiHelper;
private View otherView;
private static final String TAG = "MainActivity";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Set View that should be visible after log-in invisible initially
otherView = (View) findViewById(R.id.other_views);
otherView.setVisibility(View.GONE);
// To maintain FB Login session
uiHelper = new UiLifecycleHelper(this, callback);
uiHelper.onCreate(savedInstanceState);
}
// Called when session changes
private Session.StatusCallback callback = new Session.StatusCallback() {
@Override
public void call(Session session, SessionState state,
Exception exception) {
onSessionStateChange(session, state, exception);
}
};
// When session is changed, this method is called from callback method
private void onSessionStateChange(Session session, SessionState state,
Exception exception) {
final TextView name = (TextView) findViewById(R.id.name);
final TextView gender = (TextView) findViewById(R.id.gender);
final TextView location = (TextView) findViewById(R.id.location);
// When Session is successfully opened (User logged-in)
if (state.isOpened()) {
Log.i(TAG, "Logged in...");
// make request to the /me API to get Graph user
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) {
// Set view visibility to true
otherView.setVisibility(View.VISIBLE);
// Set User name
name.setText("Hello " + user.getName());
// Set Gender
gender.setText("Your Gender: "
+ user.getProperty("gender").toString());
location.setText("Your Current Location: "
+ user.getLocation().getProperty("name")
.toString());
}
}
}).executeAsync();
} else if (state.isClosed()) {
Log.i(TAG, "Logged out...");
otherView.setVisibility(View.GONE);
}
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
uiHelper.onActivityResult(requestCode, resultCode, data);
Log.i(TAG, "OnActivityResult...");
}
@Override
public void onResume() {
super.onResume();
uiHelper.onResume();
}
@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);
}
}
我是Java编程和Android开发的新手，所以所有的帮助都会受到赞赏。
下面你可以从我的项目中找到我的manifest.xml：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.waddapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="23" />
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<meta-data
android:name="com.facebook.sdk.ApplicationId"
android:value="@string/facebook_app_id" />
<activity
android:name=".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="com.facebook.LoginActivity"
android:theme="@style/AppTheme">
</activity>
</application>
</manifest>
答案 0 :(得分：1)
java.lang.ClassNotFoundException: Didn't find class "com.example.waddapp.MainActivity"
ClassLoader 找不到报告的类时，抛出 ClassNotFoundException 。这通常意味着 CLASSPATH 中缺少该类。
请修改清单。
答案 1 :(得分：0)
您是否在清单文件中提到了活动标签？
<activity
android:name=".MainActivity >
<intent-filter android:label="@string/app_name" >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
答案 2 :(得分：0)
你的Facebook活动应该从他们的文档中声明这样，但是这样就可以解决问题了。
<activity
android:name="com.facebook.FacebookActivity" android:configChanges="keyboard|keyboardHidden|screenLayout|screenSize|orientation"
android:theme="@android:style/Theme.Translucent.NoTitleBar" />