在Android程序设计中GridView跟ListView都是比较常用的多控件布局,而GridView更是实现九宫图的首选!本文就是介绍如何使用GridView实现九宫图。GridView的用法很多,网上介绍最多的方法就是自己实现一个ImageAdapter继承BaseAdapter,再供GridView使用,类似这种的方法本文不再重复,本文介绍的GridView用法跟之前介绍过的ListView极其类似。
我们先来看看本文代码运行的结果:
本文需要添加/修改3个文件:main.xml、night_item.xml、JAVA源代码。
main.xml源代码如下,本身是个GirdView,用于装载Item:
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<? xml version = "1.0" encoding = "utf-8" ?> < GridView xmlns:android = "http://schemas.android.com/apk/res/android" android:id = "@+id/gridview" android:layout_width = "fill_parent" android:layout_height = "fill_parent" android:numColumns = "auto_fit" android:verticalSpacing = "10dp" android:horizontalSpacing = "10dp" android:columnWidth = "90dp" android:stretchMode = "columnWidth" android:gravity = "center" /> |
这里简单介绍一下里面的某些属性:
android:numColumns="auto_fit" ,GridView的列数设置为自动
android:columnWidth="90dp",每列的宽度,也就是Item的宽度
android:stretchMode="columnWidth",缩放与列宽大小同步
android:verticalSpacing="10dp",两行之间的边距,如:行一(NO.0~NO.2)与行二(NO.3~NO.5)间距为10dp
android:horizontalSpacing="10dp",两列之间的边距。
接下来介绍 night_item.xml,这个XML跟前面ListView的ImageItem.xml很类似:
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<? xml version = "1.0" encoding = "utf-8" ?> < RelativeLayout xmlns:android = "http://schemas.android.com/apk/res/android" android:layout_height = "wrap_content" android:paddingBottom = "4dip" android:layout_width = "fill_parent" > < ImageView android:layout_height = "wrap_content" android:id = "@+id/ItemImage" android:layout_width = "wrap_content" android:layout_centerHorizontal = "true" > </ ImageView > < TextView android:layout_width = "wrap_content" android:layout_below = "@+id/ItemImage" android:layout_height = "wrap_content" android:text = "TextView01" android:layout_centerHorizontal = "true" android:id = "@+id/ItemText" > </ TextView > </ RelativeLayout > |
最后就是JAVA的源代码了,也跟前面的ListView的JAVA源代码很类似,不过多了“选中”的事件处理:
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public void onCreate(Bundle savedInstanceState) { super .onCreate(savedInstanceState); setContentView(R.layout.main); GridView gridview = (GridView) findViewById(R.id.gridview); //生成动态数组,并且转入数据 ArrayList<HashMap<String, Object>> lstImageItem = new ArrayList<HashMap<String, Object>>(); for ( int i= 0 ;i< 10 ;i++) { HashMap<String, Object> map = new HashMap<String, Object>(); map.put( "ItemImage" , R.drawable.icon); //添加图像资源的ID map.put( "ItemText" , "NO." +String.valueOf(i)); //按序号做ItemText lstImageItem.add(map); } //生成适配器的ImageItem <====> 动态数组的元素,两者一一对应 SimpleAdapter saImageItems = new SimpleAdapter( this , //没什么解释 lstImageItem, //数据来源 R.layout.night_item, //night_item的XML实现 //动态数组与ImageItem对应的子项 new String[] { "ItemImage" , "ItemText" }, //ImageItem的XML文件里面的一个ImageView,两个TextView ID new int [] {R.id.ItemImage,R.id.ItemText}); //添加并且显示 gridview.setAdapter(saImageItems); //添加消息处理 gridview.setOnItemClickListener( new ItemClickListener()); } //当AdapterView被单击(触摸屏或者键盘),则返回的Item单击事件 class ItemClickListener implements OnItemClickListener { public void onItemClick(AdapterView<?> arg0, //The AdapterView where the click happened View arg1, //The view within the AdapterView that was clicked int arg2, //The position of the view in the adapter long arg3 //The row id of the item that was clicked ) { //在本例中arg2=arg3 HashMap<String, Object> item=(HashMap<String, Object>) arg0.getItemAtPosition(arg2); //显示所选Item的ItemText setTitle((String)item.get( "ItemText" )); } } |