Class not found Android

Question

I have a custom View class in my application. I want to extend it and add it to my xml file however when I do that I get class not found exception..

Here is the xml file:

floorplan.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/RelativeLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/floorplannextbutton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginRight="47dp"
        android:layout_marginTop="22dp"
        android:text="Next" />

    <com.example.helloworld3.FloorPlan.DrawView2
        android:layout_width="match_parent"
         android:layout_height="match_parent" />


</RelativeLayout>

And this is my DrawView2 class. It is inside another class called FloorPlan but the entire code would be too long to post

DrawView2.java

public class DrawView2 extends RelativeLayout {
        Paint paint = new Paint();

public DrawView2(Context context) {
            super(context);
            paint.setColor(Color.RED);
}
public void dispatchDraw(Canvas canvas) {
            super.dispatchDraw(canvas);
for(int i =0,j=i+1 ; i<subpath.size()&& j<subpath.size(); i++, j++){


                    ux  = subpath.get(i).v.x;
                    dx  =subpath.get(i).v.y;
                    rx= subpath.get(j).v.x;
                    lx = subpath.get(j).v.y;




                canvas.drawLine(ux, dx , rx, lx, paint);


        }
}

This is what I get in the LogCat:

04-04 20:37:59.959: D/(884): HostConnection::get() New Host Connection established 0x8b92258, tid 884
04-04 20:38:07.047: W/KeyCharacterMap(884): No keyboard for id 0
04-04 20:38:07.047: W/KeyCharacterMap(884): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
04-04 20:38:16.599: D/AndroidRuntime(884): Shutting down VM
04-04 20:38:16.599: W/dalvikvm(884): threadid=1: thread exiting with uncaught exception (group=0xb5ff94f0)
04-04 20:38:16.607: E/AndroidRuntime(884): FATAL EXCEPTION: main
04-04 20:38:16.607: E/AndroidRuntime(884): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.helloworld3/com.example.helloworld3.FloorPlan}: android.view.InflateException: Binary XML file line #18: Error inflating class com.example.helloworld3.FloorPlan.DrawView2
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.app.ActivityThread.access$1500(ActivityThread.java:117)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.os.Handler.dispatchMessage(Handler.java:99)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.os.Looper.loop(Looper.java:130)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.app.ActivityThread.main(ActivityThread.java:3683)
04-04 20:38:16.607: E/AndroidRuntime(884):  at java.lang.reflect.Method.invokeNative(Native Method)
04-04 20:38:16.607: E/AndroidRuntime(884):  at java.lang.reflect.Method.invoke(Method.java:507)
04-04 20:38:16.607: E/AndroidRuntime(884):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
04-04 20:38:16.607: E/AndroidRuntime(884):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
04-04 20:38:16.607: E/AndroidRuntime(884):  at dalvik.system.NativeStart.main(Native Method)
04-04 20:38:16.607: E/AndroidRuntime(884): Caused by: android.view.InflateException: Binary XML file line #18: Error inflating class com.example.helloworld3.FloorPlan.DrawView2
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:581)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:623)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.view.LayoutInflater.inflate(LayoutInflater.java:408)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
04-04 20:38:16.607: E/AndroidRuntime(884):  at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:207)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.app.Activity.setContentView(Activity.java:1657)
04-04 20:38:16.607: E/AndroidRuntime(884):  at com.example.helloworld3.FloorPlan.onCreate(FloorPlan.java:164)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
04-04 20:38:16.607: E/AndroidRuntime(884):  ... 11 more
04-04 20:38:16.607: E/AndroidRuntime(884): Caused by: java.lang.ClassNotFoundException: com.example.helloworld3.FloorPlan.DrawView2 in loader dalvik.system.PathClassLoader[/data/app/com.example.helloworld3-1.apk]
04-04 20:38:16.607: E/AndroidRuntime(884):  at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
04-04 20:38:16.607: E/AndroidRuntime(884):  at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
04-04 20:38:16.607: E/AndroidRuntime(884):  at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.view.LayoutInflater.createView(LayoutInflater.java:471)
04-04 20:38:16.607: E/AndroidRuntime(884):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:570)
04-04 20:38:16.607: E/AndroidRuntime(884):  ... 20 more

And is my Manifest file:

AndroidManifes. xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.helloworld3"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <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=".FloorPlan"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="com.example.helloworld3.FLOORPLAN" />

                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
         <activity
            android:name=".FloorPlanTwo"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="com.example.helloworld3.FLOORPLANTWO" />

                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
         <activity
            android:name=".FloorPlanThree"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="com.example.helloworld3.FLOORPLANTHREE" />

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

    </application>

</manifest>

Thank you for all you help!

Answer 1

I had a problem similar to yours. Try these two things:

1. Extends from View, not from RelativeLayout

2. Add these constructors to your DrawView2 class

   public DrawView2(Context context)
   {
       super(context);
   }
   
   public DrawView2(Context context, AttributeSet attrs)
   {
       super(context, attrs);
   
   }
   
   public DrawView2(Context context, AttributeSet attrs, int defStyleAttr)
   {
       super(context, attrs, defStyleAttr);
   }
   

Answer 2

If DrawView2 is an inner class it should be referred to in XML as:

...
<com.example.helloworld3.FloorPlan$DrawView2
android:layout_width="match_parent"
android:layout_height="match_parent"/>
...