android组件之ImageSwitcher

  ImageSwitcher组件的主要功能是进行图片的切换，要实现图片的切换关键要实现ViewFactory。下面先附上效果图

首先配置main.xml布局用于显示界面

<LinearLayout 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:orientation="vertical"
    android:gravity="center_horizontal"
    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/imgswithcer"
        
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal" />

    <LinearLayout
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/buttonPre"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="上一张" />

        <Button
            android:id="@+id/buttonNext"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="下一张" />
    </LinearLayout>

</LinearLayout>

在activity中实现工厂类

package com.example.imgswitcherdemo;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
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.Toast;
import android.widget.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity {
	private int foot = 0;
	private Button buttonPre = null;
	private Button buttonNext = null;
	private ImageSwitcher imgswitcher = null;
	private int imgRes[] = { R.drawable.pic_head_01, R.drawable.pic_head_01,
			R.drawable.pic_head_02, R.drawable.pic_head_03,
			R.drawable.pic_head_04, R.drawable.pic_head_05,
			R.drawable.pic_head_06, R.drawable.pic_head_07,
			R.drawable.pic_head_08, R.drawable.pic_head_09,
			R.drawable.pic_head_10, R.drawable.pic_head_11,
			R.drawable.pic_head_12, R.drawable.pic_head_13,
			R.drawable.pic_head_14, R.drawable.pic_head_15,
			R.drawable.pic_head_16, R.drawable.pic_head_17 };

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		super.setContentView(R.layout.activity_main);
		this.buttonPre = (Button) this.findViewById(R.id.buttonPre);
		this.buttonNext = (Button) this.findViewById(R.id.buttonNext);
		this.imgswitcher = (ImageSwitcher) this.findViewById(R.id.imgswithcer);
		this.buttonPre.setOnClickListener(new butPreOnClickListener());
		this.buttonNext.setOnClickListener(new butNextOnClickListener());
		this.imgswitcher.setFactory(new imgFactory());//设置工厂类
		this.imgswitcher.setImageResource(MainActivity.this.imgRes[foot]);// 一定要先设置工厂后在设置资源，不然会报空指针异常

	}

	private class butPreOnClickListener implements OnClickListener {

		@Override
		public void onClick(View v) {
			if (v == buttonPre) {
				if (MainActivity.this.foot == 0) {
					// MainActivity.this.buttonPre.setEnabled(false);
					Toast.makeText(MainActivity.this, "当前已经是第一张了",
							Toast.LENGTH_LONG).show();
				} else

					MainActivity.this.foot--;
				MainActivity.this.imgswitcher
						.setImageResource(MainActivity.this.imgRes[foot]);
				// MainActivity.this.buttonPre.setEnabled(true);
			}

		}
	}

	private class butNextOnClickListener implements OnClickListener {

		@Override
		public void onClick(View v) {
			if (MainActivity.this.foot == MainActivity.this.imgRes.length - 1) {
				//MainActivity.this.buttonNext.setEnabled(false);
				Toast.makeText(MainActivity.this, "当前已经是最后一张了",
						Toast.LENGTH_LONG).show();
			} else

				MainActivity.this.foot++;
			MainActivity.this.imgswitcher
					.setImageResource(MainActivity.this.imgRes[foot]);
			//MainActivity.this.buttonNext.setEnabled(true);

		}
	}

	/*public boolean isCheckButton() {
		if (MainActivity.this.foot == 0) {
			MainActivity.this.buttonPre.setEnabled(false);
			Toast.makeText(MainActivity.this, "当前已经是第一页", Toast.LENGTH_SHORT)
					.show();
		} else
			MainActivity.this.buttonPre.setEnabled(true);
		if (MainActivity.this.foot == MainActivity.this.imgRes.length - 1) {
			MainActivity.this.buttonNext.setEnabled(false);
			Toast.makeText(MainActivity.this, "当前已经是最后一页", Toast.LENGTH_SHORT)
					.show();

		} else
			MainActivity.this.buttonNext.setEnabled(true);

		return false;

	}*/     也可以把按钮检测的功能独立出来

	private class imgFactory implements ViewFactory { //通过ViewFactory接口实现工厂类


		@Override
		public View makeView() {
			ImageView img = new ImageView(MainActivity.this);
			img.setBackgroundColor(0xFFFFFFFF); // 设置背景
			img.setScaleType(ImageView.ScaleType.CENTER);
			img.setLayoutParams(new ImageSwitcher.LayoutParams(
					LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT)); // 定义组件
			return img;
		}

	}

}