代码中设置布局

RelativeLayout downloadRelativeLayout = new RelativeLayout(context);
        downloadRelativeLayout.setBackgroundColor(Color.WHITE);
        downloadRelativeLayout.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
        downloadListView = new ListView(context);
        downloadListView.setPadding(10, 10, 10, 10);
        downloadListView.setDivider(getResources().getDrawable(R.drawable.line));
        LayoutParams listViewLayout = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
        downloadRelativeLayout.addView(downloadListView, listViewLayout);