Android开发学习笔记(四):两种方法实现图片播放器

也许有朋友想问小木为什么要学习写图片播放器呢？对于一个初学者来说，Android的页面布局，以及一些简单控件的使用是必备的基础知识，也是今后要常用的。再者，小木的学习方法是先找一些小程序做，在一定的时间段完成，以确保自己的学习进度。个人感觉单纯看视频，书籍，不动手是不行的，所以将这几天学习的两种图片播放器分享给大家，希望可以帮助到大家。

一：是基于ImageSwitcher和Button的图片播放器。

activity_image_switcher.xml中代码如下：

<RelativeLayout 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" >

    <ImageSwitcher
        android:id="@+id/imageSwitcher1"
        android:layout_width="200px"
        android:layout_height="200px"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true" 
        android:animateFirstView="true"
        
        android:inAnimation="@android:anim/fade_in"
        android:outAnimation="@android:anim/fade_out">
    </ImageSwitcher>

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignRight="@+id/imageSwitcher1"
        android:layout_below="@+id/imageSwitcher1"
        android:text="下一张" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/button1"
        android:layout_alignBottom="@+id/button1" 
        android:layout_alignLeft="@+id/imageSwitcher1"
        android:text="上一张" />

</RelativeLayout>

ImageSwitcherActivity.java中代码如下：

package com.example.imageswitcher;

import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;
import android.app.Activity;

public class ImageSwitcherActivity extends Activity {
	private Button buttonPre,buttonNext;
	private ImageSwitcher imageSwitcher;
	private int[] imageIds = {
			R.drawable.baiyang, R.drawable.chunv,R.drawable.jinniu,
			R.drawable.juxie, R.drawable.mojie,R.drawable.sheshou,
			R.drawable.shizi, R.drawable.shuangyu,R.drawable.shuangzi,
			R.drawable.shuiping, R.drawable.tiancheng,R.drawable.tianxie,};
	private int index=0;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_image_switcher);
 
        imageSwitcher = (ImageSwitcher)findViewById(R.id.imageSwitcher1);       
        imageSwitcher.setFactory(new ViewFactory() {
			
			public View makeView() {
				ImageView imageView = new ImageView(ImageSwitcherActivity.this);
				imageView.setBackgroundColor(0xff0000);
				imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
				imageView.setLayoutParams(new ImageSwitcher.LayoutParams(200,200));
				return imageView;
			}
		});
        imageSwitcher.setBackgroundResource(imageIds[index]);
//        imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
//        imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
       
        
        buttonNext = (Button)findViewById(R.id.button1);
        buttonNext.setOnClickListener(new OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(index>=0&&index<imageIds.length-1)
			     {
			      index++;
			      imageSwitcher.setBackgroundResource(imageIds[index]);
			     }else
			     {
			      index=imageIds.length-1;
			     }
				
			}			
		});
        
        buttonPre = (Button)findViewById(R.id.button2);
        buttonPre.setOnClickListener(new OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(index>0&&index<imageIds.length)
			     {
			      index--;
			     imageSwitcher.setBackgroundResource(imageIds[index]);
			     }else
			     {
			      index=imageIds.length-1;
			     }
				
			}
		});
        
    }

    
}

运行截图如下：

二：基于Imageswitcher与Gallery的图片播放器：

activity_main.xml中的代码如下：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:background="@android:color/black"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.galleryplayer.MainActivity"
    tools:ignore="MergeRootFrame" >

    <ImageSwitcher
        android:id="@+id/imageswitcher"
        android:layout_width="320dp"
        android:layout_height="270dp" />

    <Gallery
        android:id="@+id/gallery"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:background="@android:color/black"
        android:gravity="center_vertical" 
        android:spacing="3pt"/>

</RelativeLayout>

MainActivity.java中代码如下：

package com.example.galleryplayer;

import java.util.HashMap;

import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
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.ViewSwitcher.ViewFactory;

@SuppressWarnings("deprecation")
public class MainActivity extends ActionBarActivity implements OnItemSelectedListener, ViewFactory, OnItemClickListener {
		@SuppressWarnings("deprecation")
		private Gallery gallery;  
        private ImageSwitcher imageSwitcher;  
        private ImageAdapter imageAdapter;  
        private int mCurrentPos = -1;// 当前的item  
        private HashMap<Integer, ImageView> mViewMap;  
      
        private int[] resIds = new int[]  
            {
        		R.drawable.item1 ,R.drawable.item2 ,R.drawable.item3 ,R.drawable.item4 ,
        		R.drawable.item5 ,R.drawable.item6 ,R.drawable.item7 ,R.drawable.item8 ,
        	};
    @SuppressWarnings("deprecation")
	@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        gallery = (Gallery) findViewById(R.id.gallery);  
        imageAdapter = new ImageAdapter(this, resIds.length);  
        gallery.setAdapter(imageAdapter);  
        gallery.setOnItemSelectedListener(this);  
        gallery.setSelection(1);// 设置一加载Activity就显示的图片为第二张  
  
        gallery.setOnItemClickListener(this);  
  
        imageSwitcher = (ImageSwitcher) findViewById(R.id.imageswitcher);  
        imageSwitcher.setFactory(this);  
  
        // 设置动画效果 淡入淡出  
        imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));  
        imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));  
    }  
      
    public class ImageAdapter extends BaseAdapter  
    {  
        int mGalleryItemBackground;  
        private Context mContext;  
        private int mCount;// 一共多少个item  
  
        public ImageAdapter(Context context, int count)  
        {  
            mContext = context;  
            mCount = count;  
            mViewMap = new HashMap<Integer, ImageView>(count);  
           // TypedArray typedArray = obtainStyledAttributes(R.styleable.Gallery);  
            // 设置边框的样式  
          //  mGalleryItemBackground = typedArray.getResourceId(R.styleable.Gallery_android_galleryItemBackground, 0);  
        }  
  
        public int getCount()  
        {  
            return Integer.MAX_VALUE;  
        }  
  
        public Object getItem(int position)  
        {  
            return position;  
        }  
  
        public long getItemId(int position)  
        {  
            return position;  
        }  
  
        public View getView(int position, View convertView, ViewGroup parent)  
        {  
            ImageView imageview = mViewMap.get(position % mCount);  
            if (imageview == null)  
            {  
                imageview = new ImageView(mContext);  
                imageview.setImageResource(resIds[position % resIds.length]);  
                imageview.setScaleType(ImageView.ScaleType.FIT_XY);  
                imageview.setLayoutParams(new Gallery.LayoutParams(136, 88));  
                imageview.setBackgroundResource(mGalleryItemBackground);  
            }  
            return imageview;  
        }  
    }  

    // 滑动Gallery的时候，ImageView不断显示当前的item  
    @Override  
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id)  
    {  
        // imageSwitcher.setImageResource(resIds[position % resIds.length]);  
    }  
  
    // 设置点击Gallery的时候才切换到该图片  
    @Override  
    public void onItemClick(AdapterView<?> parent, View view, int position, long id)  
    {  
        if (mCurrentPos == position)  
        {  
            // 如果在显示当前图片，再点击，就不再加载。  
            return;  
        }  
        mCurrentPos = position;  
        imageSwitcher.setImageResource(resIds[position % resIds.length]);  
    }  
  
    @Override  
    public void onNothingSelected(AdapterView<?> parent)  
    {  
    }  
  
    @Override  
    public View makeView()  
    {  
        ImageView imageView = new ImageView(this);  
        imageView.setBackgroundColor(0xFF000000);  
        imageView.setScaleType(ImageView.ScaleType.CENTER_INSIDE);  
        imageView.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));  
  
        return imageView;  
    }  
  

    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */

    }

运行结果如下：

源代码下载地址：

http://download.youkuaiyun.com/detail/u013671350/7635049

http://download.youkuaiyun.com/detail/u013671350/7635041