从零開始学android<ImageSwitcher图片切换组件.二十六.>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <ImageSwitcher
        android:id="@+id/imageSwitcher1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="114dp" >
    </ImageSwitcher>

    <Button
        android:id="@+id/button1"
        style="?
android:attr/buttonStyleSmall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/button2"
        android:layout_alignBottom="@+id/button2"
        android:layout_marginRight="20dp"
        android:layout_toLeftOf="@+id/imageSwitcher1"
        android:text="上一张" />

    <Button
        android:id="@+id/button2"
        style="?android:attr/buttonStyleSmall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_toRightOf="@+id/imageSwitcher1"
        android:text="下一张" />

</RelativeLayout>

package com.example.imageswitcher;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity {
	private Button ButNext, ButPrevious;//初始化button
	private ImageSwitcher imageSwitcher;//初始化组件
	private int Images[] = { R.drawable.a1, R.drawable.a2, R.drawable.a3,
			R.drawable.a4, R.drawable.a5, R.drawable.a6 };//设置图片数据
	private int foot = 0;//设置角标

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		imageSwitcher = (ImageSwitcher) this.findViewById(R.id.imageSwitcher1);//获得组件
		ButNext = (Button) this.findViewById(R.id.button1);
		ButPrevious = (Button) this.findViewById(R.id.button2);
		imageSwitcher.setFactory(new Myfactory());//为组件设置组件工厂
		imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(
				MainActivity.this, android.R.anim.fade_in));//设置图片进入动画
		imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(
				MainActivity.this, android.R.anim.fade_out));//设置图片离开动画
		imageSwitcher.setImageResource(Images[foot++]);//设置图片

//		button事件监听
		ButNext.setOnClickListener(new View.OnClickListener() {

			@Override
			public void onClick(View view) {
				// TODO Auto-generated method stub
				imageSwitcher.setImageResource(Images[foot++]);
				MainActivity.this.CheckEnable();//设置button是否可用防止数组越界

			}
		});
//		button事件监听
		ButPrevious.setOnClickListener(new View.OnClickListener() {

			@Override
			public void onClick(View arg0) {
				// TODO Auto-generated method stub
				imageSwitcher.setImageResource(Images[foot--]);
				MainActivity.this.CheckEnable();
			}
		});

	}

	class Myfactory implements ViewFactory {

		@Override
		public View makeView() {
			// TODO Auto-generated method stub
			ImageView image = new ImageView(MainActivity.this);//设置图片组件
			image.setBackgroundColor(Color.GRAY);//设置对齐效果
			image.setScaleType(ImageView.ScaleType.CENTER);//设置剧中
			image.setLayoutParams(new ImageSwitcher.LayoutParams( // 自适应图片大小
					LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT)); // 定义组件
			return image;//返回图片

		}
	}

	public void CheckEnable() {
		if (this.foot < this.Images.length - 1) {
			this.ButNext.setEnabled(true); // button可用
		} else {
			this.ButNext.setEnabled(false); // button不可用
		}
		if (this.foot == 0) {
			this.ButPrevious.setEnabled(false); // button不可用
		} else {
			this.ButPrevious.setEnabled(true); // button可用
		}

	}
}