如何构建自定义ListView，其中每行都有矩形和圆形

Question

I have a class DrawView.java which draw a rectangle and I want to make a ListView of rectangle. I tried to draw the rectangle in getView() method of List adapter but I failed.

Can anyone help me in this issue?

My class which draw the rectangle is:

    public class DrawView extends View {
    Paint paint = new Paint();

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

    @Override
    public void onDraw(Canvas canvas) {
        paint.setColor(Color.BLACK);
        paint.setStrokeWidth(3);
        canvas.drawRect(30, 30, 180, 180, paint);
        paint.setStrokeWidth(0);
        paint.setColor(Color.CYAN);
        canvas.drawRect(33, 60, 177, 177, paint );
        paint.setColor(Color.YELLOW);
        canvas.drawRect(33, 33, 177, 60, paint );

    }

}

and my getView() method of custom adapter is:

               public View getView(final int position,  View convertView, final ViewGroup parent) {

        convertView = mInflater.inflate(R.layout.news_list_item,null);
        DrawView rl = (DrawView)convertView.findViewById(R.id.drawview);
        DrawView draw = new DrawView(c);
        rl=draw;
        return convertView;
}

My XML file is news_list_item:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:layout_margin="60dp"
    android:id="@+id/mainLayout"
     >

     <com.example.horizontalscrollview.DrawView
        android:id="@+id/drawview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true" >
      </com.example.horizontalscrollview.DrawView>



</LinearLayout>

Answer 1

You need to create a list adapter by extending BaseAdapter. Your getView method is not properly using the convertView parameter. I recommend you watch The World of ListView , which covers proper use of ListView.

UPDATE

1. Do not inflate a layout every time; only do so when convertView is null . The whole point of ListView is to recycle its views when they scroll off screen.
2. I see no reason for you to create a new instance of DrawView in getView() . It should be in the XML layout you are inflating.
3. The statement r1=draw; will not change the layout of the row in any way. All you've done is change the reference r1 to point to a different View object (the new DrawView), but that view is not actually attached to the layout in any way. If you want to add it to the layout, you need to call addView() on some other view which you intend to be the container for the new DrawView.

If you haven't done so yet, please watch The World of ListView (link above) and follow the coding patterns presented.