应用程序不是从清单中的预期类开始

Question

I'm totally new with Android Studio and I'm trying to port a working project I had in Eclipse ADT.

It's an app (ArchPanoViewer) which depends on two libraries: Zxing _which is "captureActivity" in the _ and PanoramaGL "lib_panorama". The scope of the app is to show a dialog window at the beginning, then when you press a button the barcode scanner is launched (MainActivity.java) and then the retrieved image through QRcode is shown in a panorama view (PanoramaActivity.java).

This is the generical project structure:

ArchPanoViewer
|_ app
     |_com.example.admin.archpanoviewer
         |_MainActivity.java
         |_PanoramaActivity.java
|_captureActivity
|_lib_panorama

I have a starting class inside app folder named: MainActivity.java .

Here is the manifest file for "app" that I was using when programming with Eclipse:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.admin.archpanoviewer"
xmlns:tools="http://schemas.android.com/tools">

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.FLASHLIGHT" />
<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.WRITE_SETTINGS" />

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


<activity
    android:name="com.example.admin.archpanoviewer.MainActivity"
    android:configChanges="orientation|screenSize" >
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

<activity
    android:name="com.google.zxing.client.android.CaptureActivity"
    android:screenOrientation="landscape"
    android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
    android:windowSoftInputMode="stateAlwaysHidden" >

    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>    //this part was deleted according to suggestions 

    <intent-filter>
        <action android:name="com.google.zxing.client.android.SCAN" />
        <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>
</activity>

<activity
    android:name="com.example.admin.archpanoviewer.PanoramaActivity"
    android:parentActivityName="com.example.admin.archpanoviewer.MainActivity"
    android:configChanges="orientation" >
    <meta-data
        android:name="android.support.PARENT_ACTIVITY"
        android:value="com.example.admin.archpanoviewer.MainActivity" />
</activity>

</application>

The problem in Android Studio is that the MainActivity.java is completely skipped and the application is launched as a simple Barcode scanner that retrieves QR and that's it. It's not considering at all the workflow written in the classes.

Where can I specify the starting point of the application?? For sure there is a conflict somewhere as 2 icons appear in the app drawer.. Thanks in advance!

PS I don't know if they are useful. But here there are also the build.gradles:

build.gradle (whole project):

 buildscript {
repositories {
    jcenter()
}
dependencies {
    classpath 'com.android.tools.build:gradle:1.0.0'

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
}
}

allprojects {
repositories {
    jcenter()
}
}

build.gradle (app):

apply plugin: 'com.android.application'

android {
compileSdkVersion 21
buildToolsVersion "21.1.2"

defaultConfig {
    applicationId "com.example.admin.archpanoviewer"
    minSdkVersion 8
    targetSdkVersion 21
    versionCode 1
    versionName "1.0"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
}

 dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:21.0.3'
compile project(':lib_panorama')
compile project(':captureActivity')
 }

build.gradle (Zxing)

apply plugin: 'com.android.library'
android {
compileSdkVersion 21
buildToolsVersion "21.1.2"

defaultConfig {
    minSdkVersion 7
    targetSdkVersion 21
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_7
        targetCompatibility JavaVersion.VERSION_1_7
    }
}

buildTypes {
    release {
        minifyEnabled true
        proguardFiles 'proguard-android-optimize.txt'
    }
}
}

dependencies {
}

build.gradle (PanoramaGL)

apply plugin: 'java'

dependencies {
compile files('libs/commons-httpclient-3.1.jar')
compile files('libs/android.jar')

}

I didn't manage to import Zxing as a simple library as panoramaGL.. I had method errors so I gave up. I hope this is not the problem.

EDIT 1

According to suggestions I doublechecked the manifest (updates highlighted above) and discovered this line in the running app window:

 Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.example.admin.prova/com.google.zxing.client.android.CaptureActivity }

but CaptureActivity is not set as launcher..

Answer 1

Consider this xml part

<activity
    android:name="com.example.admin.archpanoviewer.MainActivity"
    android:configChanges="orientation|screenSize" >
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />   <-------Here
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

The activity you want to start with must have MAIN here,otherwise put DEFAULT here

Answer 2

Basically Intents are a way of interactivity communication in Android.

Whenever an intent is fired, it is taken up by some-activity which was expecting this Intent and that activity responds to the intent.

Now, how does Android-runtime tells your Application's activity to start ? Well... by firing an Intent.

Basically, This intents is fired to start main activity of an application.

<action android:name="android.intent.action.MAIN" />

So... only your main-activity should be listening to this intent.

In your app... all activities are listening to these intents... which means "As far as they know... all of these are main activities."

Also... Only the launcher-activity should handle intents of this category.

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