系出名门Android(8) - 控件(View)之TextSwitcher, Gallery, ImageSwitcher, GridView, ListView, ExpandableList

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系出名门Android(8) - 控件(View)之TextSwitcher, Gallery, ImageSwitcher, GridView, ListView, ExpandableList

作者： webabcd


介绍
在 Android 中使用各种控件(View)

• TextSwitcher - 文字转换器控件（改变文字时增加一些动画效果）
• Gallery - 缩略图浏览器控件
• ImageSwitcher - 图片转换器控件（改变图片时增加一些动画效果）
• GridView - 网格控件
• ListView - 列表控件
• ExpandableList - 支持展开/收缩功能的列表控件

1、TextSwitcher 的 Demo
textswitcher.xml

代码

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

     < Button  android:id ="@+id/btnChange"  android:layout_width ="wrap_content"
        android:layout_height ="wrap_content"  android:text ="改变文字"   />

     <!--
        TextSwitcher - 文字转换器控件（改变文字时增加一些动画效果）
     -->
     < TextSwitcher  android:id ="@+id/textSwitcher"
        android:layout_width ="fill_parent"  android:layout_height ="wrap_content"   />

</ LinearLayout >

_TextSwitcher.java

代码

package  com.webabcd.view;

import  java.util.Random;

import  android.app.Activity;
import  android.os.Bundle;
import  android.view.View;
import  android.view.animation.Animation;
import  android.view.animation.AnimationUtils;
import  android.widget.Button;
import  android.widget.TextSwitcher;
import  android.widget.TextView;
import  android.widget.ViewSwitcher;

public   class  _TextSwitcher  extends  Activity  implements  ViewSwitcher.ViewFactory {

    @Override
     protected   void  onCreate(Bundle savedInstanceState) {
         //  TODO Auto-generated method stub
         super .onCreate(savedInstanceState);
         this .setContentView(R.layout.textswithcer);

        setTitle( " TextSwithcer " );

         final  TextSwitcher switcher  =  (TextSwitcher) findViewById(R.id.textSwitcher);
         //  指定转换器的 ViewSwitcher.ViewFactory
        switcher.setFactory( this );
        
         //  设置淡入和淡出的动画效果
        Animation in  =  AnimationUtils.loadAnimation( this , android.R.anim.fade_in);
        Animation out  =  AnimationUtils.loadAnimation( this , android.R.anim.fade_out);
        switcher.setInAnimation(in);
        switcher.setOutAnimation(out);

         //  单击一次按钮改变一次文字
        Button btnChange  =  (Button)  this .findViewById(R.id.btnChange);
        btnChange.setOnClickListener( new  View.OnClickListener() {
            @Override
             public   void  onClick(View v) {
                switcher.setText(String.valueOf( new  Random().nextInt()));
            }
        });
    }

     //  重写 ViewSwitcher.ViewFactory 的 makeView()，返回一个 View
    @Override
     public  View makeView() {
        TextView textView  =   new  TextView( this );
        textView.setTextSize( 36 );
         return  textView;
    }
}

2、Gallery 的 Demo
gallery.xml

代码

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

     <!--
        Gallery - 缩略图浏览器控件
            spacing - 缩略图列表中各个缩略图之间的间距
     -->
     < Gallery  android:id ="@+id/gallery"  android:layout_width ="fill_parent"
        android:layout_height ="wrap_content"  android:spacing ="20px"   />

</ LinearLayout >

_Gallery.java

代码

package  com.webabcd.view;

import  android.app.Activity;
import  android.content.Context;
import  android.os.Bundle;
import  android.view.View;
import  android.view.ViewGroup;
import  android.widget.AdapterView;
import  android.widget.BaseAdapter;
import  android.widget.Gallery;
import  android.widget.ImageView;
import  android.widget.Toast;
import  android.widget.Gallery.LayoutParams;

public   class  _Gallery  extends  Activity {

    @Override
     protected   void  onCreate(Bundle savedInstanceState) {
         //  TODO Auto-generated method stub
         super .onCreate(savedInstanceState);
         this .setContentView(R.layout.gallery);

        setTitle( " Gallery " );

        Gallery gallery  =  (Gallery) findViewById(R.id.gallery);
         //  为缩略图浏览器指定一个适配器
        gallery.setAdapter( new  ImageAdapter( this ));
         //  响应 在缩略图列表上选中某个缩略图后的 事件
        gallery.setOnItemSelectedListener( new  AdapterView.OnItemSelectedListener() {
            @Override
             public   void  onItemSelected(AdapterView <?>  parent, View v,
                     int  position,  long  id) {
                Toast.makeText(_Gallery. this , String.valueOf(position), Toast.LENGTH_SHORT).show();
            }

            @Override
             public   void  onNothingSelected(AdapterView <?>  arg0) {

            }
        });
    }

     //  继承 BaseAdapter 用以实现自定义的图片适配器
     public   class  ImageAdapter  extends  BaseAdapter {

         private  Context mContext;

         public  ImageAdapter(Context context) {
            mContext  =  context;
        }

         public   int  getCount() {
             return  mThumbIds.length;
        }

         public  Object getItem( int  position) {
             return  position;
        }

         public   long  getItemId( int  position) {
             return  position;
        }

         public  View getView( int  position, View convertView, ViewGroup parent) {
            ImageView image  =   new  ImageView(mContext);

            image.setImageResource(mThumbIds[position]);
            image.setAdjustViewBounds( true );
            image.setLayoutParams( new  Gallery.LayoutParams(
                    LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

             return  image;
        }
    }

     //  需要显示的图片集合
     private  Integer[] mThumbIds  =  { R.drawable.icon01, R.drawable.icon02,
            R.drawable.icon03, R.drawable.icon04, R.drawable.icon05 };
}

3、ImageSwitcher 的 Demo
imageswitcher.xml

代码

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

     < Gallery  android:id ="@+id/gallery"  android:layout_width ="fill_parent"
        android:layout_height ="wrap_content"  android:spacing ="20px"   />

     <!--
        ImageSwitcher - 图片转换器控件（改变图片时增加一些动画效果）
     -->
     < ImageSwitcher  android:id ="@+id/imageSwitcher"
        android:layout_width ="fill_parent"  android:layout_height ="wrap_content"   />

</ LinearLayout >

_ImageSwitcher.java

代码

package  com.webabcd.view;

import  android.app.Activity;
import  android.content.Context;
import  android.os.Bundle;
import  android.view.View;
import  android.view.ViewGroup;
import  android.view.animation.AnimationUtils;
import  android.widget.AdapterView;
import  android.widget.BaseAdapter;
import  android.widget.Gallery;
import  android.widget.ImageSwitcher;
import  android.widget.ImageView;
import  android.widget.ViewSwitcher;
import  android.widget.Gallery.LayoutParams;

//  图片转换器的使用基本同文字转换器
//  以下是一个用 ImageSwitcher + Gallery 实现的经典的图片浏览器的 Demo
public   class  _ImageSwitcher  extends  Activity  implements
        ViewSwitcher.ViewFactory {

     private  ImageSwitcher mSwitcher;

    @Override
     protected   void  onCreate(Bundle savedInstanceState) {
         //  TODO Auto-generated method stub
         super .onCreate(savedInstanceState);
         this .setContentView(R.layout.imageswithcer);

        setTitle( " ImageSwithcer " );

        mSwitcher  =  (ImageSwitcher) findViewById(R.id.imageSwitcher);
        mSwitcher.setFactory( this );
        mSwitcher.setInAnimation(AnimationUtils.loadAnimation( this ,
                android.R.anim.fade_in));
        mSwitcher.setOutAnimation(AnimationUtils.loadAnimation( this ,
                android.R.anim.fade_out));

        Gallery gallery  =  (Gallery) findViewById(R.id.gallery);
        gallery.setAdapter( new  ImageAdapter( this ));
        gallery.setOnItemSelectedListener( new  AdapterView.OnItemSelectedListener() {
            @Override
             public   void  onItemSelected(AdapterView <?>  parent, View v,
                     int  position,  long  id) {
                mSwitcher.setImageResource(mImageIds[position]);
            }

            @Override
             public   void  onNothingSelected(AdapterView <?>  arg0) {

            }
        });
    }

     public   class  ImageAdapter  extends  BaseAdapter {

         private  Context mContext;

         public  ImageAdapter(Context context) {
            mContext  =  context;
        }

         public   int  getCount() {
             return  mThumbIds.length;
        }

         public  Object getItem( int  position) {
             return  position;
        }

         public   long  getItemId( int  position) {
             return  position;
        }

         public  View getView( int  position, View convertView, ViewGroup parent) {
            ImageView image  =   new  ImageView(mContext);

            image.setImageResource(mThumbIds[position]);
            image.setAdjustViewBounds( true );
            image.setLayoutParams( new  Gallery.LayoutParams(
                    LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

             return  image;
        }
    }

     private  Integer[] mThumbIds  =  { R.drawable.icon01, R.drawable.icon02,
            R.drawable.icon03, R.drawable.icon04, R.drawable.icon05 };

     private  Integer[] mImageIds  =  { R.drawable.icon01, R.drawable.icon02,
            R.drawable.icon03, R.drawable.icon04, R.drawable.icon05 };

    @Override
     public  View makeView() {
        ImageView image  =   new  ImageView( this );
        image.setMinimumHeight( 200 );
        image.setMinimumWidth( 200 );
        image.setScaleType(ImageView.ScaleType.FIT_CENTER);
        image.setLayoutParams( new  ImageSwitcher.LayoutParams(
                LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
         return  image;
    }
}

4、GridView 的 Demo
gridview.xml

代码

<? xml version="1.0" encoding="utf-8" ?>

<!--
    GridView - 网格控件
        numColumns="auto_fit" - 列数自适应
        stretchMode - 缩放模式（stretchMode="columnWidth" - 缩放与列宽大小同步）
-->
< 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:padding ="10px"
    android:verticalSpacing ="10px"  android:horizontalSpacing ="10px"
    android:numColumns ="auto_fit"  android:columnWidth ="60px"
    android:stretchMode ="columnWidth"  android:gravity ="center" >
</ GridView >

_GridView.java

代码

package  com.webabcd.view;

import  android.app.Activity;
import  android.content.Context;
import  android.os.Bundle;
import  android.view.View;
import  android.view.ViewGroup;
import  android.widget.BaseAdapter;
import  android.widget.GridView;
import  android.widget.ImageView;

public   class  _GridView  extends  Activity {

    @Override
     protected   void  onCreate(Bundle savedInstanceState) {
         //  TODO Auto-generated method stub
         super .onCreate(savedInstanceState);
         this .setContentView(R.layout.gridview);

        setTitle( " GridView " );

        GridView gridView  =  (GridView) findViewById(R.id.gridView);
         //  指定网格控件的适配器为自定义的图片适配器
        gridView.setAdapter( new  ImageAdapter( this ));
    }

     //  自定义的图片适配器
     public   class  ImageAdapter  extends  BaseAdapter {

         private  Context mContext;

         public  ImageAdapter(Context context) {
            mContext  =  context;
        }

         public   int  getCount() {
             return  mThumbIds.length;
        }

         public  Object getItem( int  position) {
             return  position;
        }

         public   long  getItemId( int  position) {
             return  position;
        }

         public  View getView( int  position, View convertView, ViewGroup parent) {
            ImageView imageView;
             if  (convertView  ==   null ) {
                imageView  =   new  ImageView(mContext);
                imageView.setLayoutParams( new  GridView.LayoutParams( 48 ,  48 ));
                imageView.setAdjustViewBounds( false );
                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                imageView.setPadding( 5 ,  5 ,  5 ,  5 );
            }  else  {
                imageView  =  (ImageView) convertView;
            }

            imageView.setImageResource(mThumbIds[position]);

             return  imageView;
        }

         //  网格控件所需图片数据的数据源
         private  Integer[] mThumbIds  =  { R.drawable.icon01, R.drawable.icon02,
                R.drawable.icon03, R.drawable.icon04, R.drawable.icon05 };
    }
}

5、ListView 的 Demo
main_list_adapter.xml

代码

<? xml version="1.0" encoding="utf-8" ?>
<!--
    自定义列表适配器的 layout
-->
< LinearLayout  xmlns:android ="http://schemas.android.com/apk/res/android"
    android:orientation ="horizontal"  android:layout_width ="fill_parent"
    android:layout_height ="fill_parent" >
    
     < TextView  android:id ="@+id/text"  android:layout_width ="wrap_content"
        android:layout_height ="wrap_content"  android:textSize ="16sp" >
     </ TextView >
    
</ LinearLayout >

MainListAdapter.java

代码

package  com.webabcd.view;

import  java.util.List;

import  android.content.Context;
import  android.view.LayoutInflater;
import  android.view.View;
import  android.view.ViewGroup;
import  android.widget.BaseAdapter;
import  android.widget.TextView;

//  继承 BaseAdapter 以实现自定义的列表适配器
public   class  MainListAdapter  extends  BaseAdapter {

     private  LayoutInflater mInflater;
     private  List < String >  mData;

     public  MainListAdapter(Context context, List < String >  data) {
        mInflater  =  LayoutInflater.from(context);
        mData  =  data;
    }

    @Override
     public   int  getCount() {
         return  mData.size();
    }

    @Override
     public  Object getItem( int  position) {
         return  mData.get(position);
    }

    @Override
     public   long  getItemId( int  position) {
         return  position;
    }

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

        TextView text;

         if  (convertView  ==   null ) {
             //  指定一个 layout 作为自定义列表适配器的 layout
            convertView  =  mInflater.inflate(R.layout.main_list_adapter,  null );
            text  =  (TextView) convertView.findViewById(R.id.text);
            convertView.setTag(text);
        }  else  {
            text  =  (TextView) convertView.getTag();
        }
        
        String mItem  =  mData.get(position);
        text.setText(mItem);
        
         return  convertView;
    }
}

Main.java

代码

package  com.webabcd.view;

import  java.util.ArrayList;
import  java.util.List;

import  android.app.ListActivity;
import  android.content.Intent;
import  android.os.Bundle;
import  android.view.View;
import  android.widget.ListView;

//  此处要继承 ListActivity ，用以实现 ListView 的功能
public   class  Main  extends  ListActivity {
    
     private  List < String >  mData;
    
     /**  Called when the activity is first created.  */
    @Override
     public   void  onCreate(Bundle savedInstanceState) {
         super .onCreate(savedInstanceState);

        setTheme(android.R.style.Theme_Light);
        setContentView(R.layout.main);        
        mData  =  getData();
        
         //  使用自定义的列表适配器来展现数据
        MainListAdapter adapter  =   new  MainListAdapter( this , mData);
        
         //  如需使用系统内置的列表适配器，则可以使用类似如下的方法
         //  ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_expandable_list_item_1, mData);
        
         this .setListAdapter(adapter);
    }

     //  ListView 的数据源
     private  List < String >  getData()    {
        List < String >  items  =   new  ArrayList < String > ();
        
        items.add( " TextView " );
        items.add( " Button " );
        items.add( " ImageButton " );
        items.add( " ImageView " );
        items.add( " CheckBox " );
        items.add( " RadioButton " );
        items.add( " AnalogClock " );
        items.add( " DigitalClock " );
        items.add( " DatePicker " );
        items.add( " TimePicker " );
        items.add( " ToggleButton " );
        items.add( " EditText " );
        items.add( " ProgressBar " );
        items.add( " SeekBar " );
        items.add( " AutoCompleteTextView " );
        items.add( " MultiAutoCompleteTextView " );
        items.add( " ZoomControls " );
        items.add( " Include " );
        items.add( " VideoView " );
        items.add( " WebView " );
        items.add( " RatingBar " );
        items.add( " Tab " );
        items.add( " Spinner " );
        items.add( " Chronometer " );
        items.add( " ScrollView " );
        items.add( " TextSwitcher " );
        items.add( " ListView " );
        items.add( " Gallery " );
        items.add( " ImageSwitcher " );
        items.add( " GridView " );
        items.add( " ExpandableList " );
         
         return  items;
    }

     //  ListView 中某项被选中后的逻辑
    @Override
     protected   void  onListItemClick(ListView l, View v,  int  position,  long  id) {
        Intent intent  =   new  Intent();
        intent.setClassName( this ,  " com.webabcd.view._ "   +  mData.get(position));

        startActivityForResult(intent,  0 );
    }
}

6、ExpandableList 的 Demo
_ExpandableList.java

代码

package  com.webabcd.view;

import  android.app.ExpandableListActivity;
import  android.os.Bundle;
import  android.view.ContextMenu;
import  android.view.Gravity;
import  android.view.MenuItem;
import  android.view.View;
import  android.view.ViewGroup;
import  android.view.ContextMenu.ContextMenuInfo;
import  android.widget.AbsListView;
import  android.widget.BaseExpandableListAdapter;
import  android.widget.ExpandableListAdapter;
import  android.widget.ExpandableListView;
import  android.widget.TextView;
import  android.widget.Toast;
import  android.widget.ExpandableListView.ExpandableListContextMenuInfo;

//  ExpandableList - 可展开/收缩列表
//  继承 ExpandableListActivity 以实现列表的可展开/收缩的功能
public   class  _ExpandableList  extends  ExpandableListActivity {
    
     private  ExpandableListAdapter mAdapter;

    @Override
     protected   void  onCreate(Bundle savedInstanceState) {
         //  TODO Auto-generated method stub
         super .onCreate(savedInstanceState);

        setTitle( " ExpandableList " );
        
        mAdapter  =   new  MyExpandableListAdapter();
        setListAdapter(mAdapter);
        registerForContextMenu( this .getExpandableListView());
    }

     //  为列表的每一项创建上下文菜单（即长按后呼出的菜单） 
    @Override
     public   void  onCreateContextMenu(ContextMenu menu, View v,
            ContextMenuInfo menuInfo) {
        menu.setHeaderTitle( " ContextMenu " );
        menu.add( 0 ,  0 ,  0 ,  " ContextMenu " );
    }

     //  单击上下文菜单后的逻辑
    @Override
     public   boolean  onContextItemSelected(MenuItem item) {
        ExpandableListContextMenuInfo info  =  (ExpandableListContextMenuInfo) item.getMenuInfo();
        String title  =  ((TextView) info.targetView).getText().toString();

         int  type  =  ExpandableListView.getPackedPositionType(info.packedPosition);
         if  (type  ==  ExpandableListView.PACKED_POSITION_TYPE_CHILD) {
             int  groupPos  =  ExpandableListView.getPackedPositionGroup(info.packedPosition);
             int  childPos  =  ExpandableListView.getPackedPositionChild(info.packedPosition);
            
            Toast.makeText( this , title  +   "  - Group Index:  "   +  groupPos  +   "  Child Index:  "   +  childPos, Toast.LENGTH_SHORT).show();
            
             return   true ;
        }  else   if  (type  ==  ExpandableListView.PACKED_POSITION_TYPE_GROUP) {
             int  groupPos  =  ExpandableListView.getPackedPositionGroup(info.packedPosition);
            Toast.makeText( this , title  +   "  - Group Index:  "   +  groupPos, Toast.LENGTH_SHORT).show();
            
             return   true ;
        }

         return   false ;
    }

     public   class  MyExpandableListAdapter  extends  BaseExpandableListAdapter {

         //  父列表数据
         private  String[] groups  =  
        { 
             " group1 " , 
             " group2 " , 
             " group3 " ,
             " group4 "  
        };
         //  子列表数据
         private  String[][] children  =  
        {
            {  " child1 "  },
            {  " child1 " ,  " child2 "  },
            {  " child1 " ,  " child2 " ,  " child3 "  },
            {  " child1 " ,  " child2 " ,  " child3 " ,  " child4 "  }
        };
        
        @Override
         public  Object getChild( int  groupPosition,  int  childPosition) {
             return  children[groupPosition][childPosition];
        }

        @Override
         public   long  getChildId( int  groupPosition,  int  childPosition) {
             return  childPosition;
        }

        @Override
         public   int  getChildrenCount( int  groupPosition) {
             return  children[groupPosition].length;
        }

         //  取子列表中的某一项的 View
        @Override
         public  View getChildView( int  groupPosition,  int  childPosition,
                 boolean  isLastChild, View convertView, ViewGroup parent) {
            TextView textView  =  getGenericView();
            textView.setText(getChild(groupPosition, childPosition).toString());
             return  textView;
        }

        @Override
         public  Object getGroup( int  groupPosition) {
             return  groups[groupPosition];
        }

        @Override
         public   int  getGroupCount() {
             return  groups.length;
        }

        @Override
         public   long  getGroupId( int  groupPosition) {
             return  groupPosition;
        }

         //  取父列表中的某一项的 View
        @Override
         public  View getGroupView( int  groupPosition,  boolean  isExpanded,
                View convertView, ViewGroup parent) {
            TextView textView  =  getGenericView();
            textView.setText(getGroup(groupPosition).toString());
             return  textView;
        }

        @Override
         public   boolean  hasStableIds() {
             return   true ;
        }

        @Override
         public   boolean  isChildSelectable( int  groupPosition,  int  childPosition) {
             return   true ;
        }
                
         //  获取某一项的 View 的逻辑
         private  TextView getGenericView() {
            AbsListView.LayoutParams lp  =   new  AbsListView.LayoutParams(
                    ViewGroup.LayoutParams.FILL_PARENT,  48 );
            TextView textView  =   new  TextView(_ExpandableList. this );
            textView.setLayoutParams(lp);
            textView.setGravity(Gravity.CENTER_VERTICAL  |  Gravity.LEFT);
            textView.setPadding( 32 ,  0 ,  0 ,  0 );
             return  textView;
        }
    }
}

OK
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