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

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;
	}

}

实现效果如下：