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:
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<? 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:
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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:
- 由于SimpleAdapter 对象 是根据Map 建立的 ,所以他们的Key一定要相同才行,否则无法生成。
- 关于闪退现象:我才用的是经过压缩过的图片,如果是加载高清大图很可能出现OOM现象,这是我们需要对图片进行压缩,具体可以参照:http://www.tuohang.net/article/246070.html
- 这里cell文件还是和往常一样,只是个简单的ImageView罢了,注意设置它的 id 要与活动中调用它的地方相同,这里就不过多描述了。
希望本文所述对大家Android程序设计有所帮助。
原文链接:https://blog.csdn.net/qq_43377749/article/details/84978387