How to add a custom class that extends View to Main Activity?

Question

I have problems with adding a custom class to my Main Activity.

code in my custom class:

public class DetailView extends View {

    public DetailView(Context context) {
        super(context);

        this.setBackgroundColor(0xFF00FF00 );



    }
}

code in main activity:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    linearLayout = (LinearLayout) findViewById(R.id.linearLayout1);

    LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
    linearLayout.setOrientation(LinearLayout.VERTICAL);


    txt = new TextView(this);
    txt.setText("hello");
    txt.setId(6);
    txt.setLayoutParams(params);
    linearLayout.addView(txt);

    DetailView detailView = new DetailView(this.getApplicationContext());
    linearLayout.addView(detailView);

}

Why can't is see the detailView? Im new to android development so I need any help I can get, or some good links or anything. Thanks

Answer 1

The view is added, but it has no dimension set. Looking at existing code I guess you want it do fill the width and have a small height - just assuming. So try the following:

DetailView detailView = new DetailView(this);
params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, 2); // 2 pixels height
linearLayout.addView(detailView, params);

Also, the context of the DetailView is the activity, not the application context.