Android: Unable to instantiate activity ComponentInfo

问题

I have a problem on android developing app. I made a research first my error and i found out that there are other people who are having the same problem like me. I read all the comments a tried everything but still i'm having the same error.

Here my error

05-29 12:39:36.701: E/AndroidRuntime(823): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.georgepanayi.mixfmcyprus.radio/com.georgepanayi.mixfmcyprus.radio.Main_Activity}: java.lang.ClassNotFoundException: Didn't find class "com.georgepanayi.mixfmcyprus.radio.Main_Activity" on path: /data/app/com.georgepanayi.mixfmcyprus.radio-1.apk
05-29 12:39:36.701: E/AndroidRuntime(823):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2106)
05-29 12:39:36.701: E/AndroidRuntime(823):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
05-29 12:39:36.701: E/AndroidRuntime(823):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-29 12:39:36.701: E/AndroidRuntime(823):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
05-29 12:39:36.701: E/AndroidRuntime(823):  at android.os.Handler.dispatchMessage(Handler.java:99)
05-29 12:39:36.701: E/AndroidRuntime(823):  at android.os.Looper.loop(Looper.java:137)
05-29 12:39:36.701: E/AndroidRuntime(823):  at android.app.ActivityThread.main(ActivityThread.java:5041)
05-29 12:39:36.701: E/AndroidRuntime(823):  at java.lang.reflect.Method.invokeNative(Native Method)
05-29 12:39:36.701: E/AndroidRuntime(823):  at java.lang.reflect.Method.invoke(Method.java:511)
05-29 12:39:36.701: E/AndroidRuntime(823):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-29 12:39:36.701: E/AndroidRuntime(823):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-29 12:39:36.701: E/AndroidRuntime(823):  at dalvik.system.NativeStart.main(Native Method)
05-29 12:39:36.701: E/AndroidRuntime(823): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.georgepanayi.mixfmcyprus.radio.Main_Activity" on path: /data/app/com.georgepanayi.mixfmcyprus.radio-1.apk
05-29 12:39:36.701: E/AndroidRuntime(823):  at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:65)
05-29 12:39:36.701: E/AndroidRuntime(823):  at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
05-29 12:39:36.701: E/AndroidRuntime(823):  at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
05-29 12:39:36.701: E/AndroidRuntime(823):  at android.app.Instrumentation.newActivity(Instrumentation.java:1054)
05-29 12:39:36.701: E/AndroidRuntime(823):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2097)
05-29 12:39:36.701: E/AndroidRuntime(823):  ... 11 more

I have read that the problem is with the activity on the manifest and here is my class and the manifest class

package com.georgepanayi.mixfmcyprus.radio;

import org.holoeverywhere.app.Activity;

import android.os.Bundle;

public class Main_Activity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_mix_fm__main);
    }

}

manifest

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

    <uses-sdk
        android:minSdkVersion="10"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/Theme.Mixfmradio" >
        <activity
            android:name=".Main_Activity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>

</manifest>

Also I'm using libraries like Holoeverywhere, SherlockActionBar 4.3.1 and ViewPagerIndicator 2.4.1

can anyone find the problem?

Thank you

回答1:

The problem was with the Holoeverywhere. what I have done in order to solve the problem was to go to the properties of my project -> Java build path -> order and export and then select the option android private libraries. then i have added the android:name="org.holoeverywhere.app.Application" inside of the tag in the manifest.

回答2:

This is my manifest. Works for me. You need android:name="MyApp" in application declaration.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.georgepanayi.mixfmcyprus.radio"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="10"
        android:targetSdkVersion="17" />

    <instrumentation android:label="TestStack" android:name=".Main_Activity" android:targetPackage="com.georgepanayi.mixfmcyprus.radio"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:name=".Main_Activity"
        android:theme="@style/AppTheme" >

        <activity
            android:name=".Main_Activity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>

</manifest>

You can see the project demo https://github.com/Prototik/HoloEverywhere.git

来源：https://stackoverflow.com/questions/16810628/android-unable-to-instantiate-activity-componentinfo