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Android惯用控件之HorizontalScrollView代替Gallery

分类: IT文章 • 2024-08-18 16:46:01
Android常用控件之HorizontalScrollView代替Gallery

最近在学习Gallery发现在API Level 16以后已经不使用，废弃了这个肯定是有更好的来替代，查了下文档就发现HorizontalScrollView这个类；

        HorizontalScrollView用于布局的容器，可以放置让用户使用滚动条查看的视图层次结构，允许视图结构比手机的屏幕大.。HorizontalScrollView 是一种 框架布局， 这意味着你可以将包含要滚动的完整内容的子视图放入该容器； 该子视图本身也可以是具有复杂层次结构的布局管理器。一般使用横向的 LinearLayout 作为子视图，使用户可以滚动其中显示的条目。


不要将 HorizontalScrollView 和 列表视图 组合使用， 因为列表视图有自己的滚动处理.更重要的是，组合使用会使列表视图针对大的列表所做的重要优化失效， 因为 HorizontalScrollView 会强制列表视图显示其所有条目，以使用由 HorizontalScrollView 提供滚动处理的容器。HorizontalScrollView 只支持水平方向的滚动。

以下是ImageSwitcher和HorizontalScrollView的组合效果图：

Android惯用控件之HorizontalScrollView代替Gallery

Activity类

package com.example.viewgroupdemo;

import java.util.HashMap;
import java.util.Map;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;

import com.example.hsv.AppConstant;
import com.example.hsv.HSVAdapter;
import com.example.hsv.HSVLayout;

/**
 * 2013.10.12 类似图片浏览的例子
 * 
 * @author Administrator
 * 
 */
public class MainActivity extends Activity implements ViewFactory {

	public ImageSwitcher imageSwitcher = null; // 图片切换
	private HSVLayout movieLayout = null;
	private HSVAdapter adapter = null;
	private IntentFilter intentFilter = null;
	private BroadcastReceiver receiver = null;
	private int nCount = 0;
	// pic in the drawable
	private Integer[] images = { R.drawable.pre0, R.drawable.pre1,
			R.drawable.pre2, R.drawable.pre3, R.drawable.pre4, R.drawable.pre5,
			R.drawable.pre6, R.drawable.pre7, R.drawable.pre8, R.drawable.pre9,
			R.drawable.pre10 };

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		imageSwitcher = (ImageSwitcher) findViewById(R.id.image_switcher);
		imageSwitcher.setFactory(this);
		movieLayout = (HSVLayout) findViewById(R.id.movieLayout);
		adapter = new HSVAdapter(this);
		for (int i = 0; i < images.length; i++) {
			Map<String, Object> map = new HashMap<String, Object>();
			map.put("image", images[i]);
			// map.put("image", getResources().getDrawable(images[i]));
			map.put("index", (i+1));
			adapter.addObject(map);
		}
		movieLayout.setAdapter(adapter);
		// 设置当前显示的图片
		imageSwitcher.setImageResource(images[nCount]);
	}

	@Override
	protected void onPause() {
		// TODO Auto-generated method stub
		super.onPause();
		unregisterReceiver(receiver);
	}

	@Override
	protected void onResume() {
		// TODO Auto-generated method stub
		super.onResume();
		if (receiver == null) {
			receiver = new UpdateImageReceiver();
		}
		registerReceiver(receiver, getIntentFilter());
	}

	/**
	 * 创建一个消息过滤器
	 * 
	 * @return
	 */
	private IntentFilter getIntentFilter() {
		if (intentFilter == null) {
			intentFilter = new IntentFilter();
			intentFilter.addAction(AppConstant.UPDATE_IMAGE_ACTION);
		}
		return intentFilter;
	}
	
	/**
	 * 创建一个用于添加到视图转换器(ViewSwitcher)中的新视图
	 */
	@Override
	public View makeView() {
		// TODO Auto-generated method stub
		ImageView imageView = new ImageView(getApplicationContext());
		imageView.setBackgroundColor(0xFF000000);
		imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
		imageView.setLayoutParams(new ImageSwitcher.LayoutParams(
				LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
		return imageView;
	}
	
	class UpdateImageReceiver extends BroadcastReceiver{

		@Override
		public void onReceive(Context context, Intent intent) {
			// TODO Auto-generated method stub
			if(intent.getAction().equals(AppConstant.UPDATE_IMAGE_ACTION)){
				int index = intent.getIntExtra("index", Integer.MAX_VALUE);
				imageSwitcher.setImageResource(images[index-1]);
				System.out.println("UpdateImageReceiver----" + index);
			}
		}
		
	}
}

自定义HSVLayout.java 

package com.example.hsv;

import java.util.Map;

import android.content.Context;
import android.content.Intent;
import android.util.AttributeSet;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.Toast;

public class HSVLayout extends LinearLayout {

	private HSVAdapter adapter;
	private Context context;

	public HSVLayout(Context context, AttributeSet attrs) {
		super(context, attrs);
		this.context = context;
	}

	public void setAdapter(HSVAdapter adapter) {
		this.adapter = adapter;
		for (int i = 0; i < adapter.getCount(); i++) {
			final Map<String, Object> map = adapter.getItem(i);
			View view = adapter.getView(i, null, null);
			view.setPadding(10, 0, 10, 0);
			// 为视图设定点击监听器
			view.setOnClickListener(new OnClickListener() {
				@Override
				public void onClick(View v) {
					Toast.makeText(context, "您选择了" + map.get("index"),
							Toast.LENGTH_SHORT).show();
					Intent intent = new Intent();
					intent.setAction(AppConstant.UPDATE_IMAGE_ACTION);
					intent.putExtra("index", (Integer)map.get("index"));
					context.sendBroadcast(intent);
					
				}
			});
			this.setOrientation(HORIZONTAL);
			this.addView(view, new LinearLayout.LayoutParams(
					/*LayoutParams.WRAP_CONTENT*/300, LayoutParams.WRAP_CONTENT));
		}
	}
}
还需要定义一个适配器HSVAdapter.java 

package com.example.hsv;

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

import com.example.viewgroupdemo.R;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;

/**
 * 为画廊定义适配器
 * @author Administrator
 *
 */
public class HSVAdapter extends BaseAdapter {

	private List<Map<String,Object>> list;
	private Context context;
	public HSVAdapter(Context context){
		this.context=context;
		this.list=new ArrayList<Map<String,Object>>();
	}
	@Override
	public int getCount() {
		return list.size();
	}

	@Override
	public Map<String,Object> getItem(int location) {
		return list.get(location);
	}

	@Override
	public long getItemId(int arg0) {
		return arg0;
	}

	public void addObject(Map<String,Object> map){
		list.add(map);
		notifyDataSetChanged();
	}
	@Override
	public View getView(int location, View arg1, ViewGroup arg2) {
		View view = LayoutInflater.from(context).inflate(R.layout.movie,null);
		ImageView image=(ImageView)view.findViewById(R.id.movie_image);
		Map<String,Object> map=getItem(location); //获取当前的Item
		//image.setBackground((Drawable)map.get("image"));
		image.setBackgroundResource((Integer) map.get("image"));
		return view;
	}

}

main.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" >

    <ImageSwitcher
        android:id="@+id/image_switcher"
        android:layout_width="match_parent"
        android:layout_height="400dp" />

    <HorizontalScrollView
        android:id="@+id/hsv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:scrollbars="none" >

        <com.example.hsv.HSVLayout
            android:id="@+id/movieLayout"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />
    </HorizontalScrollView>

</LinearLayout>

hsv.xml 

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:xmz="http://xmz.com"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" >

    <com.example.hsv.ImageViewBorder
        android:id="@+id/movie_image"
        android:layout_width="wrap_content"
        android:layout_height="400dp"
        android:layout_alignParentBottom="true"
        xmz:BorderColor="GRAY" />

</RelativeLayout>

示例代码：

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