android学习笔记15——Galley

Gallery==>画廊视图

Gallery和Spinnery父类相同——AbsSpinner,表明Garrey和Spinner都是一个列表框。

两者之间的区别是：Spinner显示的是一个垂直列表框，Gallery显示的是一个水平列表框；

　　　　　　　　 Spinner的作用是供用户选择，而Gallery则允许用户通过拖动来查看上一个、下一个列表项。

Garrey常用XML属性：

android:animationDuration	setAnimationDuration(int)	设置列表项切换时的动画帧持续时间
android:gravity	setGravity(int)	设置对其方式
android:spacing	setSpacing(int)	设置Gallery内列表项之间的间距
android: unselectedAlpha	setUnselectedAlpha(float)	设置没有选中的列表项的透明度

注意:

Gallery用法类似Spinner，使用Adapter提供数据源，Adapter的getView()所返回的View将作为Gallery列表的列表项；

通过OnItemSelectedListener监听器监听选择项的改变。

实例一

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

布局文件==》
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >
 
    <ImageSwitcher
        android:id="@+id/switcher"
        android:layout_width="320dp"
        android:layout_height="320dp" />
 
    <Gallery
        android:id="@+id/gallery"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:spacing="3pt"
        android:unselectedAlpha="0.6" />
 
</LinearLayout>
 
代码实现==》
package com.example.mygrallery;
 
import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.ActionBar.LayoutParams;
import android.content.res.TypedArray;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;
 
@SuppressWarnings("deprecation")
@SuppressLint("InlinedApi")
public class MainActivity extends Activity
{
    private int[] ImageIds = new int[]
    { R.drawable.one, R.drawable.tw, R.drawable.th, R.drawable.eight, R.drawable.ele,
            R.drawable.five, R.drawable.four, R.drawable.nice, R.drawable.seven, R.drawable.six,
            R.drawable.sl, R.drawable.ss, R.drawable.sw, R.drawable.ten, R.drawable.tw,
            R.drawable.oneowne };
 
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        final ImageSwitcher switcher = (ImageSwitcher) this.findViewById(R.id.switcher);
        final Gallery gallery = (Gallery) this.findViewById(R.id.gallery);
 
        switcher.setFactory(new ViewFactory()
        {
            @Override
            public View makeView()
            {
                ImageView img = new ImageView(MainActivity.this);
                img.setBackgroundColor(0xff0000);
                img.setScaleType(ImageView.ScaleType.FIT_CENTER);
                img.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.WRAP_CONTENT,
                        LayoutParams.WRAP_CONTENT));
                return img;
            }
        });
        // 设置图片更换的动画效果
        switcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
        switcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
        // 创建DataAdapter对象,为gallery提供数据
        BaseAdapter adapter = new BaseAdapter()
        {
            @Override
            public int getCount()
            {
                // TODO Auto-generated method stub
                return ImageIds.length;
            }
 
            @Override
            public Object getItem(int position)
            {
                // TODO Auto-generated method stub
                return position;
            }
 
            @Override
            public long getItemId(int position)
            {
                // TODO Auto-generated method stub
                return position;
            }
 
            @Override
            public View getView(int position, View convertView, ViewGroup parent)
            {
                ImageView img = new ImageView(MainActivity.this);
                img.setImageResource(ImageIds[position % ImageIds.length]);
                // 设置ImageView的缩放类型
                img.setScaleType(ImageView.ScaleType.FIT_XY);
                img.setLayoutParams(new Gallery.LayoutParams(75, 110));
                // TypedArray arr= obtainStyledAttributes(R.)
                // img.setBackgroundResource(resid);
 
                return img;
            }
        };
 
        gallery.setAdapter(adapter);
        gallery.setOnItemSelectedListener(new OnItemSelectedListener()
        {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id)
            {
                // TODO Auto-generated method stub
                switcher.setImageResource(ImageIds[position % ImageIds.length]);
            }
 
            @Override
            public void onNothingSelected(AdapterView<?> parent)
            {
                // TODO Auto-generated method stub
            }
        });
    }
 
    @Override
    public boolean onCreateOptionsMenu(Menu menu)
    {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
 
}