java.lang.ClassCastException: android.app.Application cannot be cast to

调用自定义的application类时候报错java.lang.ClassCastException: android.app.Application cannot be cast to com.android.myapp

解决方法是，在manifest.xml文件中添加<application>且便签android:name为自定义个类名，如果有则修改<application>标签的android:name

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

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />
    <application
        android:name=".MyApp"
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
    </application>
</manifest>