控件(View)之TextSwitcher, Gallery, ImageSwitcher, GridView, ListView, ExpandableList

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>