<ImageSwitcher>简单学习之支持动画的图片浏览器

当你跌入谷底的时候，不要绝望，抬起头，你会看见一片灿烂的星空。

---

package com.crazyit.ui.viewanimator;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
import android.widget.ViewSwitcher;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * ImageSwitcher 的简单功能与用法
 * ImageSwitcher 继承了ViewSwitcher
 * 使用 ImageSwitcher 只需要实现2步
 * (1) 为 ImageSwitcher提供一个 ViewFactory  该ViewFactory组件生成的View组件必须是 imageview
 * (2) 需要切换图片的时候,只要调用 ImageSwitcher的 setImageDrawable(Drawable drawable), setImageResource(int resId)
 * 和setImageURi(Uri uri)方法更换图片即可.
 */
public class ImageSwitcherActivity extends AppCompatActivity {

    //设置一个 资源图片数组
    int[] imageIds = new int[]{R.drawable.b, R.drawable.c, R.drawable.d,
            R.drawable.e, R.drawable.f, R.drawable.fuqi};
    ImageSwitcher switcher;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_image_switcher);

        //创建一个 list对象 List对象的元素是 Map
        List<Map<String, Object>> listItems = new ArrayList<>();

        for (int i = 0; i < imageIds.length; i++) {
            Map<String, Object> listItem = new HashMap<>();
            listItem.put("image", imageIds[i]);

            listItems.add(listItem);
        }

        //获取显示图片的 imageSwitcher
        switcher = (ImageSwitcher) findViewById(R.id.imageSwitcher);

        //为ImageSwitcher 设置图片切换的动画效果
        switcher.setFactory(new ViewSwitcher.ViewFactory() {
            @Override
            public View makeView() {

                ImageView imageView = new ImageView(ImageSwitcherActivity.this);

                //设置缩放类型
                imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
                //设置 宽高
                imageView.setLayoutParams(new ViewSwitcher.LayoutParams(ViewSwitcher.LayoutParams.WRAP_CONTENT,
                        ViewSwitcher.LayoutParams.WRAP_CONTENT));

                //返回对象
                return imageView;
            }
        });

        //创建一个 simpleAdapter
        SimpleAdapter simpleAdapter = new SimpleAdapter(this,
                listItems,
                R.layout.cell,
                new String[]{"image"},
                new int[]{R.id.image01}
                );

        GridView gridView = (GridView) findViewById(R.id.grid01);
        gridView.setAdapter(simpleAdapter);

        //添加列表项被单机的事件监听器
        gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                switcher.setImageResource(imageIds[position]);
                Toast.makeText(ImageSwitcherActivity.this, "22", Toast.LENGTH_SHORT).show();
            }
        });
    }
}

---

布局文件

<?xml version="1.0" encoding="utf-8"?>
<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"
    tools:context="com.crazyit.ui.viewanimator.ImageSwitcherActivity">

    <GridView
        android:id="@+id/grid01"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:horizontalSpacing="2dp"
        android:numColumns="4"
        android:verticalSpacing="2dp"></GridView>

    <ImageSwitcher
        android:id="@+id/imageSwitcher"
        android:layout_width="320dp"
        android:layout_height="320dp"
       android:layout_gravity="center"
        android:inAnimation="@android:anim/fade_in"
        android:outAnimation="@android:anim/fade_out"></ImageSwitcher>
</LinearLayout>

列表项的布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_horizontal"
    android:orientation="vertical"
    android:padding="4dp">

    <ImageView
        android:id="@+id/image01"
        android:layout_width="50dp"
        android:layout_height="50dp" />
</LinearLayout>