9.用户接口UI布局----View控件的概述之ViewGroup

公告

1.LinearLayout 线性布局（主要分为水平和垂直线性布局）

android:layout_width="fill_parent"
android:layout_height="fill_parent"

fill_parent会使得android:layout_weight="1" 分配的比重均衡

android:gravity 表示子控件对齐方式或是内容文本的对齐方式

// horizontal表示垂直线性布局

// vertical表示水平线性布局

2.AbsoluteLayout 绝对布局

android:layout_x="1px"
android:layout_y="30px"

用于定位

3.FrameLayout框架布局（加入的控件可以层叠）

android:layout_gravity 用于定位

4.RelativeLayout相对布局
子控件位置相关：android:layout_toRightOf

子控件距离相关：android:layout_margin="10dp"
子控件与父控件位置相关：android:layout_alignParentBottom

对齐相关：android:layout_alignBaseline

<RelativeLayout >
<TextView android:id="@+id/tt1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="ThirdActivity6"

android:layout_alignParentBottom="true"
/>
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="DatePickerDialog"
android:layout_toRightOf="@id/tt1"
android:onClick="showDatePickerDialog" android:layout_alignBaseline="@id/tt1"/>
</RelativeLayout>

5.TableLayout 表格布局

隐藏指定列用逗号隔开：android:collapseColumns

扩张指定列（留有空白的话）：android:stretchColumns

收缩指定列（换行）适应屏幕：android:shrinkColumns

6.ListView (is a view group that displays a list of scrollable items.)

java.lang.Object
android.view.View
android.view.ViewGroup
android.widget.AdapterView<T extends android.widget.Adapter>
android.widget.AbsListView
android.widget.ListView

6.1 ArrayAdapter

// layout/list.xml

android:list 名字不能改变

android:empty 名字不能改变传入的数组或list为空数据时显示，注意不能传入null

// Myactivity （extends ListActivity）

可以不需要setContentView()，则使用默认的layout

android:scrollingCache="false" 拖动背景改变去使能
android:divider="" 间隔

@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);

setContentView(R.layout.list);
// Get the string array
String[] countries = getResources().getStringArray(R.array.planets_array);
ListAdapter adapter=new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,countries);
setListAdapter(adapter);
Log.i(TAG, "ThirdActivity-->onCreate");
}

// values/strings.xml

<string-array name="planets_array">
<item>Mercury</item>
<item>Venus</item>
<item>Earth</item>
<item>Mars</item>
<item>Jupiter</item>
<item>Saturn</item>
<item>Uranus</item>
<item>Neptune</item>
</string-array>

6.2 SimpleAdapter

// layout/copy.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >

<TextView
android:id="@+id/id"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="编号"
android:background="#0000FF"
android:layout_weight="1"/>
<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="姓名"
android:background="#0000FF"
android:layout_weight="1"/>
<TextView
android:id="@+id/gender"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="性别"
android:background="#0000FF"
android:layout_weight="1"/>
</LinearLayout>
<ListView android:id="@id/android:list"
android:layout_width="fill_parent"
android:layout_height="fill_parent" ></ListView>
</LinearLayout>

// layout/list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >

<TextView
android:id="@+id/id"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="编号"
android:background="#0000FF"
android:layout_weight="1"/>
<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="姓名"
android:background="#0000FF"
android:layout_weight="1" />
<TextView
android:id="@+id/gender"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="性别"
android:background="#0000FF"
android:layout_weight="1 " />

</LinearLayout>

// Myactivity （extends ListActivity）

setContentView(R.layout.copy);

ListAdapter adapter1=new SimpleAdapter(this,getData(),R.layout.list_item,

new String[]{"id","name","gender"},
new int[]{R.id.id,R.id.name,R.id.gender});
// setListAdapter(adapter);

setListAdapter(adapter1);

(

)

6.3 SimpleCursorAdapter

Cursor cursor = getContentResolver().query(People.CONTENT_URI, null, null, null, null);
startManagingCursor(cursor);

ListAdapter listAdapter = new SimpleCursorAdapter(this, R.layout.list_item,
cursor, new String[]{People._ID,People.NAME,People.NUMBER},
new int[]{R.id.id,R.id.name,R.id.gender});
//setListAdapter(adapter1);
setListAdapter(listAdapter);

Cursor cursor = getContentResolver().query(People.CONTENT_URI, null, null, null, null);先获得一个指向系统通讯录数据库的Cursor对象获得数据来源。

　startManagingCursor(cursor);我们将获得的Cursor对象交由Activity管理，这样Cursor的生命周期和Activity便能够自动同步，省去自己手动管理Cursor。

需要在AndroidManifest.xml中如权限：<uses-permission android:name="android.permission.READ_CONTACTS"></uses-permission>

7 GridView

java.lang.Object
android.view.View
android.view.ViewGroup
android.widget.AdapterView<T extends android.widget.Adapter>

android.widget.AbsListView
android.widget.AbsListViewandroid.widget.GridView

// layout/grid.xml

<?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:columnWidth="90dp"
android:numColumns="auto_fit"
android:verticalSpacing="10dp"
android:horizontalSpacing="10dp"
android:stretchMode="columnWidth"
android:gravity="center"
/>

// ayout/grid_item.xml

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="6dp"
android:orientation="vertical" >

<ImageView
android:id="@+id/id"
android:layout_width="100dp"
android:layout_height="150dp"
android:scaleType="fitXY"
android:layout_gravity="center"
android:padding="4dp"
android:background="#0000FF" />
<TextView
android:id="@+id/tite"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:padding="4dp"
android:background="#0000FF"/>

</LinearLayout>

// MyActivity.java

onCreate片段

setContentView(R.layout.grid);
GridView gridview = (GridView) findViewById(R.id.gridview);
gridview.setAdapter(new ImageAdapter(this, getData()));

gridview.setOnItemClickListener(new OnItemClickListener() {

public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Toast.makeText(GridViewDemoActivity.this, "" + position, Toast.LENGTH_SHORT).show();
}
});

list方法

private List<Map<String, Object>> getData()
{
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();

Map<String, Object> map = new HashMap<String, Object>();
map.put("title", "G0");
map.put("imageid", R.drawable.sample_0);
list.add(map);

map = new HashMap<String, Object>();
map.put("title", "G1");
map.put("imageid", R.drawable.sample_1);
list.add(map);
map = new HashMap<String, Object>();
map.put("title", "G2");
map.put("imageid", R.drawable.sample_2);
list.add(map);
map = new HashMap<String, Object>();
map.put("title", "G3");
map.put("imageid", R.drawable.sample_3);
list.add(map);
map = new HashMap<String, Object>();
map.put("title", "G4");
map.put("imageid", R.drawable.sample_4);
list.add(map);
map = new HashMap<String, Object>();
map.put("title", "G5");
map.put("imageid", R.drawable.sample_5);
list.add(map);
map = new HashMap<String, Object>();
map.put("title", "G6");
map.put("imageid", R.drawable.sample_6);
list.add(map);
map = new HashMap<String, Object>();
map.put("title", "G7");
map.put("imageid", R.drawable.sample_7);
list.add(map
return list;
}

内部类三部曲

class ImageAdapter extends BaseAdapter{

		private Context context;
		private List<Image> images;
		private LayoutInflater inflater;
		
		public ImageAdapter(Context context, List<Map<String, Object>> list) {
			super();
			this.context=context;
			images=getImages(list);
			inflater = LayoutInflater.from(context);
		}

		private List<Image> getImages(List<Map<String, Object>> list) {
			List<Image> images=new ArrayList<Image>();
			for(Map<String, Object> map:list){
				
				images.add(new Image(map.get("title").toString(), Integer.parseInt(map.get("imageid").toString())));
			}
			return images;
		}

		public int getCount() {
			
			return images.size();
		}

		public Image getItem(int position) {
			// TODO Auto-generated method stub
			return images.get(position);
		}

		public long getItemId(int position) {
			// TODO Auto-generated method stub
			return position;
		}

		public View getView(int position, View convertView, ViewGroup parent) {
			ViewHolder viewHolder = new ViewHolder();
			if (convertView==null) {
				convertView = inflater.inflate(R.layout.grid_item, null);
				viewHolder.title=(TextView)convertView.findViewById(R.id.tite);
				viewHolder.image=(ImageView)convertView.findViewById(R.id.id);
				convertView.setTag(viewHolder);
			}else{
				viewHolder = (ViewHolder)convertView.getTag();
			}
			viewHolder.title.setText(images.get(position).getTitle());
			viewHolder.image.setImageResource(images.get(position).getImageId());
			return convertView;
		}
		
	}

class Image{
		private String title;
		private int  imageId;
		public String getTitle() {
			return title;
		}
		public void setTitle(String title) {
			this.title = title;
		}
		public int getImageId() {
			return imageId;
		}
		public void setImageId(int imageid) {
			this.imageId = imageid;
		}
		public Image(String title,int  imageid){
			this.title=title;
			this.imageId=imageid;
		}
	}

class ViewHolder{
		TextView title;
		ImageView image;
		
	}

posted on 2012-07-29 20:34 SuperbookKing 阅读(216) 评论(0) 收藏举报

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