Question

I am creating an app which requires a custom layout.But after running my app it simple force closes.Can anyone suggest the reason and solution if possible

Thanx in advance

this is my main Activity

public class MainActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }  
}

this is my custom layout class

public class Odo extends View {
    private Paint p;
    private RectF rect;
    public Odo(Context context) {
        super(context);
        Log.e("odo", "constructor");
        init();
        // TODO Auto-generated constructor stub
    }
    public void init() {
        Log.e("odo", "inside init()");
        rect = new RectF();
        p = new Paint(Paint.ANTI_ALIAS_FLAG);
        p.setColor(Color.GREEN);

    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        // TODO Auto-generated method stub
        super.onSizeChanged(w, h, oldw, oldh);
        Log.e("odo", "inside onSizeChange");
        rect.set(0, 0, w, h);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        // TODO Auto-generated method stub
        Log.e("odo", "inside onDraw");
        super.onDraw(canvas);

        canvas.drawRect(rect, p);

    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // TODO Auto-generated method stub
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        Log.e("odo", "inside onMeasure");
    }
}

And this is my XML file

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
    <com.example.odo.Odo
        android:id="@+id/odom"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
         />
</LinearLayout>

Answer 1

I believe you need to provide the default constructors that takes AttributeSet and/or int for style reference. For example:

public class Odo extends View {
    private Paint p;
    private RectF rect;

    public Odo(Context context) {
        super(context);
        Log.e("odo", "constructor");
        init();
        // TODO Auto-generated constructor stub
    }

    public Odo (Context context, AttributeSet attrs) {
        super(context, attrs);
        Log.e("odo", "constructor");
        init();
    }

    public Odo (Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        Log.e("odo", "constructor");
        init();
    }

    public void init() {
        Log.e("odo", "inside init()");
        rect = new RectF();
        p = new Paint(Paint.ANTI_ALIAS_FLAG);
        p.setColor(Color.GREEN);

    }

//.....  and so on

}