Android: Creating custom view

Question

In my app I'm trying to create my own HorizontalScrollView that "snaps" when you swipe through the views inside of it. Everytime it tries to load the layout, it crashes. So, I'm taking baby steps. I'm new to creating custom views programmatically, so if there may be some "common sense" mistakes.

Here is my CustomView.java file:

import android.content.Context;
import android.view.View;

public class CustomView extends View {

    public CustomView(Context context) {
        super(context);
    }
}

Here is my MainActivity.java file:

import android.app.Activity;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_layout);
    }
}

Here is my main_layout.xml file:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:orientation="vertical"
    android:id="@+id/lchoose_weapon"
    tools:context=".ChooseWeaponActivity" >

<TextView
    android:id="@+id/tvTitle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:text="Title"
    android:textSize="40sp" />

<com.javaknight.ultimaterps.CustomView
    android:id="@+id/CustomVw"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/tvTitle"
    android:layout_centerHorizontal="true" />
<TextView
    android:id="@+id/tv2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/CustomVm"
    android:layout_centerHorizontal="true"
    android:text="Another TextView Below" />

<Button
    android:id="@+id/bOK"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/tv2"
    android:layout_centerHorizontal="true"
    android:text="ok" />

</RelativeLayout>

Using the following code fails to display the layout. As soon as I remove the CustomView from the xml file, it works fine. I want the xml layout file to have the Custom View inside of it.

Diego Torres Milano · Accepted Answer · 2013-01-06 04:25:19Z

8

You should create all the constructors in your custom View:

public CusatomView(Context context) {
    super(context);
}

public CustomView(Context context, AttributeSet attrs) {
    super(context, attrs);
}

public CustomView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
}

If you do it, I guess your layout will work.

answered Jan 6, 2013 at 4:25

Diego Torres Milano

69.9k9 gold badges116 silver badges145 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Android: Creating custom view

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related