android ImageSwitcher案例
public class
ImageSwitcher
extends ViewSwitcher| java.lang.Object | ||||||
| ↳ | android.view.View | |||||
| ↳ | android.view.ViewGroup | |||||
| ↳ | android.widget.FrameLayout | |||||
| ↳ | android.widget.ViewAnimator | |||||
| ↳ | android.widget.ViewSwitcher | |||||
| ↳ | android.widget.ImageSwitcher |
（译者注：ImageSwitcher是Android中控制图片展示效果的一个控件，如：幻灯片效果...，颇有感觉啊，做相册一绝。）
我们在Windows 平台上要查看多张图片，最简单的办法就是通过 "Window 图片和传真查看器“在 ”下一张“ 和”上一张“之间切换，Android平台上可以通过 ImageSwitcher 类来实现这一效果。ImageSwitcher 类必须设置一个ViewFactory,主要用来将显示的图片和父窗口区分开来，因此需要实现ViewSwitcher.ViewFactory接口，通过makeView()方法来显示图片，这里会返回一个ImageView 对象，而方法 setImageResource用来指定图片资源。首先先让我们看看这个例子的运行效果。
一、重要方法
setImageURI(Uri uri)：设置图片地址
setImageResource(int resid)：设置图片资源库
setImageDrawable(Drawable drawable)：绘制图片
=========================================================
案例一：
1.定义布局文件imageswitcher.xml
<?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"
>
<ImageSwitcher
android:id="@+id/imageSwitcher_id"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
>
</ImageSwitcher>
<Gallery
android:id="@+id/Imageswitcher_gallery_id"
android:background="#55000000"
android:layout_width="match_parent"
android:layout_height="60dp"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:gravity="center_vertical"
android:spacing="16dp">
</Gallery>
</RelativeLayout>
2.定义java文件ImageSwitcherDemo.java
package com.test;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.Gallery.LayoutParams;
import android.widget.ViewSwitcher.ViewFactory;
public class ImageSwitcherDemo extends Activity implements
OnItemSelectedListener, ViewFactory {
private ImageSwitcher is;
private Gallery gallery;
private Integer[] mThumbIds = {
R.drawable.gallery_01,R.drawable.gallery_02,R.drawable.gallery_03,
R.drawable.gallery_04,R.drawable.gallery_05,R.drawable.gallery_06,
};
private Integer[] mImageIds =
{
R.drawable.gallery_01, R.drawable.gallery_02,R.drawable.gallery_03,
R.drawable.gallery_04,R.drawable.gallery_05,R.drawable.gallery_06,
};
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.imageswitcher);
is = (ImageSwitcher) findViewById(R.id.switcher);
is.setFactory(this);
is.setInAnimation(AnimationUtils.loadAnimation(this,
android.R.anim.fade_in));
is.setOutAnimation(AnimationUtils.loadAnimation(this,
android.R.anim.fade_out));
gallery = (Gallery) findViewById(R.id.gallery);
gallery.setAdapter(new ImageAdapter(this));
gallery.setOnItemSelectedListener(this);
}
@Override
public View makeView() {
ImageView i = new ImageView(this);
i.setBackgroundColor(0xFF000000);
i.setScaleType(ImageView.ScaleType.FIT_CENTER);
i.setLayoutParams(new ImageSwitcher.LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
return i;
}
public class ImageAdapter extends BaseAdapter {
public ImageAdapter(Context c) {
mContext = c;
}
public int getCount() {
return mThumbIds.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView i = new ImageView(mContext);
i.setImageResource(mThumbIds[position]);
i.setAdjustViewBounds(true);
i.setLayoutParams(new Gallery.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
// i.setBackgroundResource(R.drawable.);
return i;
}
private Context mContext;
}
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position,
long id) {
is.setImageResource(mImageIds[position]);
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
// TODO Auto-generated method stub
}
}
3.执行效果：
===================================================
案例二：自定义：
1.自定义一个Gallery文件：
package com.test;
import java.text.AttributedCharacterIterator.Attribute;
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.Gallery;
public class Gallery_define extends Gallery {
public Gallery_define(Context context,AttributeSet attrs) {
super(context,attrs);
// TODO Auto-generated constructor stub
}
//重写onFling方法，将滑动的速率降低
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
// TODO Auto-generated method stub
return super.onFling(e1, e2, velocityX/3, velocityY);
}
}
2：接下来自定义一个gallery布局文件：gallery_define.xml
<?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:orientation="vertical" >
<ImageView android:id="@+id/item_gallery_image"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:scaleType="fitXY"/>
<TextView
android:id="@+id/item_gallery_text"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center"/>
</LinearLayout>
3：定义布局文件：gallerydemo.xml
<?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:orientation="vertical" >
<com.test.Gallery_define
android:id="@+id/gallery_define"
android:background="#55000000"
android:layout_width="match_parent"
android:layout_height="80dp"
android:gravity="center_vertical"
android:spacing="2dp"
>
</com.test.Gallery_define>
<ImageSwitcher android:id="@+id/switcher_define"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
/>
</LinearLayout>
4.java文件：ImageSwitcherGallery_define
package com.test;
import java.util.HashMap;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.view.Window;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.ViewSwitcher.ViewFactory;
public class ImageSwitcherGallery_define extends Activity implements
OnItemSelectedListener, ViewFactory {
//定义ImageSwitcher类对象
private ImageSwitcher imageSwitcher;
//文本资源w
private String []titles={"标题A","标题B","标题C","标题D","标题E","标题F"};
//大图资源
private int[] ThumbIds=
{
R.drawable.gallery_01,R.drawable.gallery_02,R.drawable.gallery_03,
R.drawable.gallery_04,R.drawable.gallery_05,R.drawable.gallery_06,
};
//大图资源对于的小图资源
private int[] imageIds=
{
R.drawable.gallery_01,R.drawable.gallery_02,R.drawable.gallery_03,
R.drawable.gallery_04,R.drawable.gallery_05,R.drawable.gallery_06,
};
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
//设置窗体无标题
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.gallerydemo);
imageSwitcher = (ImageSwitcher)findViewById(R.id.switcher_define);
imageSwitcher.setFactory(this);
imageSwitcher=(ImageSwitcher)findViewById(R.id.switcher_define);
//设置图片的滑动效果
imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
Gallery gallery=(Gallery)findViewById(R.id.gallery_define);
//设置Gallery的适配器
gallery.setAdapter(new ImageAdapter(this,ThumbIds.length));
//Gallery中每个条目的点击事件监听
gallery.setOnItemClickListener(itemListener);
//设置默认起始位置为第二张图片
gallery.setSelection(1);
}
OnItemClickListener itemListener = new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int position,
long arg3) {
if (curruntPos == position) {
return;
} else
curruntPos = position;
imageSwitcher.setImageResource(ThumbIds[position % ThumbIds.length]);
}
};
@Override
public View makeView() {
ImageView imageView =new ImageView(this);
imageView.setBackgroundColor(TRIM_MEMORY_BACKGROUND);
imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
imageView.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT));
return imageView;
}
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
imageSwitcher.setImageResource(ThumbIds[arg2%imageIds.length]);
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
class ImageAdapter extends BaseAdapter
{
private int galleryItenBackgroud;
//定义map存储划过的位置
private HashMap<Integer, View> viewMaps;
private int count;
//定义布局加载器
private LayoutInflater inflater;
public ImageAdapter(Context c,int count) {
this.count=count;
viewMaps = new HashMap<Integer, View>(count);
inflater=LayoutInflater.from(ImageSwitcherGallery_define.this);
//定义图片的背景样式
TypedArray a=obtainStyledAttributes(R.styleable.Gallery);
galleryItenBackgroud=a.getResourceId(R.styleable.Gallery_android_galleryItemBackground, 0);
//定义可以重复使用，可回收
a.recycle();
}
@SuppressLint("ParserError")
@Override
public int getCount() {
// 设置循环的次数
return Integer.MAX_VALUE;
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
View viewGroup=viewMaps.get(position%count);
ImageView imageView=null;
TextView textView = null;
if(viewGroup==null)
{
viewGroup =inflater.inflate(R.layout.gallery_define, null);
imageView=(ImageView)viewGroup.findViewById(R.id.item_gallery_image);
textView = (TextView)viewGroup.findViewById(R.id.item_gallery_text);
imageView.setBackgroundResource(galleryItenBackgroud);
viewMaps.put(position%count, viewGroup);
imageView.setImageResource(imageIds[position%imageIds.length]);
textView.setText(titles[position%imageIds.length]);
}
return viewGroup;
}
}
//记录当前位置
private int curruntPos=-1;
}
5：效果图：
