Android UI教程 - Android ImageSwitcher

要在图像从一个图像过渡到另一个图像时对图像应用一些动画，您需要与Gallery视图一起使用ImageSwitcher。

例子

通过添加以下语句来修改activity_main.xml文件:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Images of Android" />

    <Gallery
        android:id="@+id/gallery1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

    <ImageSwitcher
        android:id="@+id/switcher1"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentBottom="true" />

</LinearLayout>

将以下内容保存到res / values / attrs.xml。

<?xml version="1.0" encoding="utf-8"?>
<resources>
   <declare-styleable name="Gallery1">
       <attr name="android:galleryItemBackground" />
   </declare-styleable>
</resources>

将以下语句添加到MainActivity.java文件中:

package com.java2s.myapplication3.app;
// w ww  .  j a va  2 s .  c  o m
import android.app.Activity;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity implements ViewFactory {
    Integer[] imageIDs = {
            R.drawable.ic_launcher,
            R.drawable.ic_launcher,
            R.drawable.ic_launcher,
            R.drawable.ic_launcher,
            R.drawable.ic_launcher,
            R.drawable.ic_launcher,
            R.drawable.ic_launcher
    };

    private ImageSwitcher imageSwitcher;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        imageSwitcher = (ImageSwitcher) findViewById(R.id.switcher1);
        imageSwitcher.setFactory(this);
        imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_in));
        imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_out));

        Gallery gallery = (Gallery) findViewById(R.id.gallery1);
        gallery.setAdapter(new ImageAdapter(this));
        gallery.setOnItemClickListener(new OnItemClickListener()
        {
            public void onItemClick(AdapterView<?> parent,
                                    View v, int position, long id)
            {
                imageSwitcher.setImageResource(imageIDs[position]);
            }
        });
    }

    public View makeView()
    {
        ImageView imageView = new ImageView(this);
        imageView.setBackgroundColor(0xFF000000);
        imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
        imageView.setLayoutParams(new
                ImageSwitcher.LayoutParams(
                LayoutParams.FILL_PARENT,
                LayoutParams.FILL_PARENT));
        return imageView;
    }

    public class ImageAdapter extends BaseAdapter
    {
        private Context context;
        private int itemBackground;

        public ImageAdapter(Context c)
        {
            context = c;
            //setting the style
        //    TypedArray a = obtainStyledAttributes(R.styleable.Gallery1);
        //    itemBackground = a.getResourceId(
         //           R.styleable.Gallery1_android_galleryItemBackground, 0);
       //     a.recycle();
        }

        //returns the number of images
        public int getCount()
        {
            return imageIDs.length;
        }

        //returns the item
        public Object getItem(int position)
        {
            return position;
        }

        //returns the ID of an item
        public long getItemId(int position)
        {
            return position;
        }

        //returns an ImageView view
        public View getView(int position, View convertView, ViewGroup parent)
        {
            ImageView imageView = new ImageView(context);

            imageView.setImageResource(imageIDs[position]);
            imageView.setScaleType(ImageView.ScaleType.FIT_XY);
            imageView.setLayoutParams(new Gallery.LayoutParams(150, 120));
            imageView.setBackgroundResource(itemBackground);

            return imageView;
        }
    }

}