add combobox example.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1181 bbd45198-f89e-11dd-88c7-29a3b14d5316

examples/gui/demo_view_combobox.c

+/*
+ * 程序清单：label控件演示
+ *
+ * 这个例子会在创建出的view上添加几个不同类型的label控件
+ */
+#include "demo_view.h"
+#include <rtgui/widgets/combobox.h>
+
+struct rtgui_combobox_item items[] = 
+{
+	{"item 1", RT_NULL},
+	{"item 2", RT_NULL},
+	{"item 3", RT_NULL},
+	{"item 4", RT_NULL},
+	{"item 5", RT_NULL},
+};
+
+/* 创建用于演示combobox控件的视图 */
+rtgui_view_t* demo_view_combobox(rtgui_workbench_t* workbench)
+{
+	rtgui_rect_t rect;
+	rtgui_view_t* view;
+	rtgui_combobox_t* box;
+
+	/* 先创建一个演示用的视图 */
+	view = demo_view(workbench, "ComboBox View");
+
+	/* 获得视图的位置信息 */
+	demo_view_get_rect(view, &rect);
+	rect.x1 += 5;
+	rect.x2 -= 5;
+	rect.y1 += 5;
+	rect.y2 = rect.y1 + 20;
+	/* 创建一个label控件 */
+	box = rtgui_combobox_create(items, sizeof(items)/sizeof(items[0]), &rect);
+	/* view是一个container控件，调用add_child方法添加这个box控件 */
+	rtgui_container_add_child(RTGUI_CONTAINER(view), RTGUI_WIDGET(box));
+
+	return view;
+}