Android学习笔记 ImageSwitcher图片切换组件的使用

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <ImageSwitcher 
        android:id="@+id/myImageSwitcher"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="horizontal">
        <Button
            android:id="@+id/Btn_last"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:enabled="false"
            android:text="上一张图片" />
           <Button
            android:id="@+id/Btn_next"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:enabled="true"
            android:text="下一张图片" />
    </LinearLayout>
</LinearLayout>

MainActivity.java

public class MainActivity extends Activity {
    private Button btnLast=null;
    private Button btnNext=null;
    private ImageSwitcher myImageSwitcher=null;
    private int[] imgRes=new int[] {
            R.drawable.png_01,
            R.drawable.png_02,
            R.drawable.png_03,
            R.drawable.png_04,
            R.drawable.png_05,
            R.drawable.png_06,
            R.drawable.png_07,
            R.drawable.png_08
    }; //定义资源文件数组
    private int foot=0; //表示当前图片的标记
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        this.myImageSwitcher=(ImageSwitcher)super.findViewById(R.id.myImageSwitcher);
        this.btnLast=(Button)super.findViewById(R.id.Btn_last);
        this.btnNext=(Button)super.findViewById(R.id.Btn_next);
        this.btnLast.setOnClickListener(new OnClickListenerImpl());
        this.btnNext.setOnClickListener(new OnClickListenerImpl());
        this.myImageSwitcher.setFactory(new ViewFactoryImpl());
        this.myImageSwitcher.setImageResource(imgRes[this.foot++]);
        this.myImageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in)); //设置图片切换效果
        this.myImageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out)); //设置图片切换效果
    }
    
    private class OnClickListenerImpl implements OnClickListener{

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            switch (v.getId()) {
            case R.id.Btn_last:
                MainActivity.this.myImageSwitcher.setImageResource(MainActivity.this.imgRes[MainActivity.this.foot--]);
                checkBtnEnable();
                break;
            case R.id.Btn_next:
                MainActivity.this.myImageSwitcher.setImageResource(MainActivity.this.imgRes[MainActivity.this.foot++]);
                checkBtnEnable();
                break;
            default:
                break;
            }
        }
        
    }
    
    //按钮检测
    private void checkBtnEnable(){ 
        if(this.foot<this.imgRes.length-1){ //检查是否为最后一张图片
            this.btnNext.setEnabled(true);
        }else{
            this.btnNext.setEnabled(false);
        }
        if(this.foot==0){ //检查是否为第一张图片
            this.btnLast.setEnabled(false);
        }else{
            this.btnLast.setEnabled(true);
        }
    }
    
    //工厂
    private class ViewFactoryImpl implements ViewFactory{

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