Android开发之ImageSwitcher相册功能实例分析_Android

本文实例讲述了android开发之imageswitcher相册功能。分享给大家供大家参考，具体如下：

简介：

1.imageswitcher是viewswitcher的子类，所以imageswitcher继承了viewswitcher素有的特性

2.作为viewswitcher的子类，它比viewswitcher使用更加方便，主要体现在：①. 重写了setnext() ②. 重写了showprevious()方法。所以其实用起来，要比viewswitcher更为方便。

3.中重要的是：imageswitcher增加了图片切换动画，使得图片的切换更加自然

这里看下运行效果：

这个例子中，看考了疯狂android讲义，采用imageswicher结合gridview实现的，一下问布局文件：

<?xml version="1.0" encoding="utf-8" ?>
<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:gravity="center_horizontal">
    <!--定义一个gridview组件-->
    <gridview
      android:id="@+id/grid01"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:listselector="@null"
      android:numcolumns="3"
      android:horizontalspacing="2dp"
      android:verticalspacing="2dp"
      android:gravity="center">
    </gridview>
    <!--定义一个imageswitcher组件-->
    <imageswitcher
      android:id="@+id/switcher"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_gravity="center_horizontal"
      android:padding="50dp"
      android:inanimation="@android:anim/fade_in"
      android:outanimation="@android:anim/fade_out"
      android:background="@color/colorprimarydark"
      android:visibility="gone">
    </imageswitcher>
</relativelayout>

关于gridview 有两种常用的监听事件：

gridview.setonitemselectedlistener 和 gridview.setonitemclicklistener

关于imageswitcher 设置imageswitcher 采用了imageswitcher.setfactory 方法：

public class mainactivity extends activity {
  int[] imageid = new int[]{
      r.drawable.a0,r.drawable.a1,r.drawable.a2,r.drawable.a4,
      r.drawable.a5,r.drawable.a6,r.drawable.a7,r.drawable.a8,
      r.drawable.a9,r.drawable.a00,r.drawable.a02,r.drawable.a02,
  };
  imageswitcher imageswitcher ;
  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_main);
    //创建一个list对象，list对象的元素是map
    list<map<string,object>> listitems = new arraylist<map<string, object>>();
    for (int i = 0 ; i < imageid.length ; i++ ){
      map<string,object> listitem = new hashmap<string, object>();
      listitem.put("image",imageid[i]);
      listitems.add(listitem);
    }
    //获取显示图片的imageswitcher
    imageswitcher = (imageswitcher) findviewbyid(r.id.switcher);
    //为imageswitcher设置动画效果
    imageswitcher.setfactory(new viewswitcher.viewfactory() {
      @override
      public view makeview() {
        //创建imageview对象
        imageview imageview = new imageview(mainactivity.this);
        imageview.setscaletype(imageview.scaletype.fit_xy);
        imageview.setlayoutparams(new imageswitcher.layoutparams(viewgroup.layoutparams.match_parent,viewgroup.layoutparams.match_parent));
        //返回imageview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.image1});
    gridview gridview = (gridview) findviewbyid(r.id.grid01);
    //为gridview设置adapter
    gridview.setadapter(simpleadapter);
    //添加列表选中监听事件
    gridview.setonitemselectedlistener(new adapterview.onitemselectedlistener() {
      @override
      public void onitemselected(adapterview<?> parent, view view, int position, long id) {
        imageswitcher.setvisibility(view.visible);
        imageswitcher.setclickable(true);
        //显示当前选中图片
        imageswitcher.setimageresource(imageid[position]);
      }
      @override
      public void onnothingselected(adapterview<?> parent) {
      }
    });
    //添加列表被单击的监听器
    gridview.setonitemclicklistener(new adapterview.onitemclicklistener() {
      @override
      public void onitemclick(adapterview<?> parent, view view, int position, long id) {
        imageswitcher.setvisibility(view.visible);
        imageswitcher.setclickable(true);
        //显示被单击图片
        imageswitcher.setimageresource(imageid[position]);
      }
    });
    //为imageswitcher添加监听事件
    imageswitcher.setonclicklistener(new view.onclicklistener() {
      @override
      public void onclick(view v) {
        imageswitcher.setvisibility(view.gone);
        imageswitcher.setclickable(false);
      }
    });
    imageswitcher.setclickable(false);
  }
}

几点值得注意的：