Sample code which extends View class and using layout xml file

Question

I am new to the Android world.... it will be a great help if someone correct me... what am I doing wrong the below code...

• Requirement : Need to create a custom View(using xml layout file) so that the same view should be used inside in my application activities. Here i go with the sample code which i am working on,

cutomviewxml.xml

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

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Large Text"
        android:textAppearance="?android:attr/textAppearanceLarge" />
</LinearLayout>

Extended View class ...code...

mycustomTextview.java

public class mycustomTextview extends View {

    private View mView;
    Context mycontext;

    public mycustomTextview(Context context, AttributeSet attrs) {
        super(context, attrs);
        // TODO Auto-generated constructor stub

    this.mycontext = context;

    LayoutInflater inflater;
    inflater = (LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    mView = inflater.inflate(R.layout.cutomviewxml, null);
    }

Activity main.xml file

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


     <com.motorola.mycustomTextview
         android:id="@+id/customtextview"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         android:layout_below="@+id/textView2"
         android:layout_marginLeft="143dp"
         android:layout_marginTop="69dp"
         android:layout_toRightOf="@+id/textView1" />

</RelativeLayout>

Activity class sample.java ..

public class sample extends Activity{

    private static final String LOG_TAG = "sampleActivity";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.i(LOG_TAG,"OnCreate of sampleActivity");
        setContentView(R.layout.main);
}
}

Answer 1

I think you have done a little mistake in mycustomTextview, when you inflate your layout you have to pass ViewGroup too, you can use this line

mView = inflater.inflate(R.layout.cutomviewxml, this);

Answer 2

To get access to views inside of custom view override onFinishInflate() method and use findViewById(). For the problem at hand the solution will be as follows.

public class mycustomTextview extends LinearLayout {

    Context mycontext;
    private TextView textView1;

    public mycustomTextview(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.mycontext = context;
    }

    @Override
    protected void onFinishInflate() {
         super.onFinishInflate();
         textView1=(TextView) findViewById(R.id.textView1);
    }
}

Answer 3

Use this in your xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent">
        <yourpackagename.viewclassname android:id="@+id/myView1" 
         android:layout_width="wrap_content" 
         android:layout_height="wrap_content"></yourpackagename.viewclassname>
</LinearLayout>

Answer 4

public class ExampleView extends FrameLayout {

        ImageView mImage;

        public ExampleView(Context context) {
            super(context);
            init(context);
        }

        public void init(Context context) {
            View view = inflate(context, R.layout.my_view_layout,this);
            view.findViewById(R.id.image)
        }
}