Android控件组合应用四

接上一篇，我们已经有了自定义的ListView了，在其中具备了Header和Footer，现在这个ListView已经可以在多个类似的界面中使用了，而且Header和Footer都可以使用更复杂的View来实现。

接下来，是为ListView添加数据的时候了，根据《Android控件组合应用一》一文中对数据结构的描述，我们在MainActivity中添加一个方法initSite()用于构造测试数据。该类的代码如下：

 

package com.wenbin.test;

import com.wenbin.test.site.Blog;
import com.wenbin.test.site.SinaSite;
import com.wenbin.test.site.Site;
import com.wenbin.test.site.User;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.TextView;

public class MainActivity extends Activity implements OnItemClickListener {
	private TextView usernameTextview;
	private Site site;
	
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		
		initSite();
		
		usernameTextview=(TextView)findViewById(R.id.TextViewUsername);
		BlogListView sinaListView=(BlogListView)findViewById(R.id.sinaList);
		sinaListView.setOnItemClickListener(this);
		sinaListView.init(site);
		
		findViewById(R.id.BtnWrite).setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				//TODO:
			}
		});
		
		findViewById(R.id.BtnRefresh).setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				//TODO:
			}
		});
		
		updateUserNameTextView();
	}

	private void updateUserNameTextView() {
		usernameTextview.setText(R.string.unAuthUser);
	}
	
	@Override
	public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
		//TODO:
	}
	
	private void initSite(){
		site=new SinaSite();

		Blog blog=new Blog(site);
		blog.setPic("http://ww3.sinaimg.cn/thumbnail/6b8527b3jw6dbydoikpzuj.jpg");
		User user=new User();
		user.setVerified(true);
		blog.setUser(user);
		site.addBlog(blog);
		
		blog=new Blog(site);
		user=new User();
		user.setVerified(true);
		blog.setUser(user);
		Blog retBlog=new Blog();
		user=new User();
		user.setProfileImageUrl("");
		user.setScreenName("reply");
		retBlog.setUser(user);
		retBlog.setText("[爱你]求喜欢");
		retBlog.setPic("http://tp4.sinaimg.cn/1658122963/50/1282754213");
		blog.setRetweetedBlog(retBlog);
		site.addBlog(blog);
		
		for(int i=0;i<5;i++){
			try {
				Thread.sleep(200);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			user=new User();
			blog=new Blog(site);
			blog.setUser(user);
			site.addBlog(blog);
		}
	}
}

然后，我们为每个列表项来写一个布局文件blogview.xml，布局如下：

 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:orientation="vertical"
  android:padding="10dp" android:descendantFocusability="blocksDescendants"
  android:background="@color/white">
  <RelativeLayout android:layout_width="fill_parent" 
  	android:layout_height="fill_parent" >
 	<WebView android:id="@+id/profileImage"
 		android:layout_width="48dp"
 		android:layout_height="48dp"
 		android:scrollbars="none"
 		android:layout_alignParentLeft="true"
 		android:background="@drawable/portrait">
 	</WebView>
 	<ImageView android:id="@+id/vImage"
 		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
 		android:layout_alignRight="@+id/profileImage"
 		android:layout_alignBottom="@+id/profileImage"
 		android:src="@drawable/v">
 	</ImageView>
 	<RelativeLayout android:layout_alignParentRight="true"
 		android:layout_toRightOf="@+id/profileImage"
 		android:layout_width="fill_parent"
 		android:layout_height="fill_parent"
 		android:layout_marginLeft="10dp">
 		<TextView android:id="@+id/userName" android:layout_height="wrap_content" android:layout_alignParentTop="true"
 			android:textColor="@color/red"
 			android:textSize="15sp"
 			android:paddingBottom="5dp" android:layout_width="fill_parent">
 		</TextView>
  		<TextView android:id="@+id/blogText" android:layout_height="wrap_content"
 			android:layout_below="@+id/userName"
 			android:textColor="@color/black"
 			android:textSize="15sp" android:layout_width="wrap_content">
 		</TextView>
 		<WebView android:id="@+id/smallImage"
	 		android:layout_width="68dp"
	 		android:layout_height="48dp"
	 		android:scrollbars="none"
	 		android:layout_below="@+id/blogText"
	 		android:background="@drawable/image">
	 	</WebView>	
		<RelativeLayout android:layout_width="fill_parent" 
 			android:layout_height="wrap_content"
 			android:layout_below="@+id/smallImage"
 			android:background="@drawable/popup"
 			android:paddingTop="10dp"
 			android:paddingBottom="5dp"
 			android:paddingLeft="5dp"
 			android:paddingRight="5dp"
 			android:id="@+id/reBlog">
	 		<TextView android:id="@+id/reBlogText" android:layout_width="fill_parent"
	 			android:layout_height="wrap_content"
	 			android:layout_below="@+id/reUserName"
	 			android:textColor="@color/black"
	 			android:textSize="15sp">
	 		</TextView> 	
	 		<WebView android:id="@+id/reImage"
		 		android:layout_width="68dp"
		 		android:layout_height="48dp"
		 		android:scrollbars="none"
		 		android:layout_below="@+id/reBlogText"
		 		android:background="@drawable/image">
		 	</WebView>		
 		</RelativeLayout>	
 		<TextView android:id="@+id/sourceText" android:layout_width="fill_parent"
 			android:layout_height="wrap_content" 
 			android:layout_alignLeft="@+id/userName"
 			android:layout_below="@+id/reBlog"
 			android:textColor="@color/blue"
 			android:textSize="10sp"
 			android:paddingBottom="5dp">
 		</TextView>	
 	</RelativeLayout>
  </RelativeLayout>
</LinearLayout>

至此，可以通过派生ListAdapter来实现我们的Adapter了，代码如下：

 

package com.wenbin.test;

import java.util.Iterator;
import java.util.Set;

import com.wenbin.test.site.Blog;
import android.content.Context;
import android.database.DataSetObserver;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebView;
import android.widget.Adapter;
import android.widget.ImageView;
import android.widget.ListAdapter;
import android.widget.TextView;

public class BlogAdapter implements ListAdapter {
	private static final String AT = "@";	
	private static final String COLON=": ";
	
	private Set<Blog> blogs;
	private Context context;
	
	public BlogAdapter(Set<Blog> blogs,Context context){
		this.blogs=blogs;
		this.context=context;
	}

	@Override
	public boolean areAllItemsEnabled() {
		return true;
	}

	@Override
	public boolean isEnabled(int arg0) {
		return true;
	}

	@Override
	public int getCount() {
		return blogs.size();
	}

	@Override
	public Blog getItem(int position) {
		if (position<0 || position>=getCount())
			return null;
	
		if (blogs!=null){
			Iterator<Blog> iterator=blogs.iterator();
			int i=0;
			while(iterator.hasNext()){
				if (i==position){
					return iterator.next();
				}
				else{
					iterator.next();
					i++;
				}
			}
		}
		return null;
	}

	@Override
	public long getItemId(int position) {
		return 0;
	}

	@Override
	public int getItemViewType(int position) {
		return Adapter.IGNORE_ITEM_VIEW_TYPE;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		View view=null;
		if (convertView==null){
			LayoutInflater li=LayoutInflater.from(context);
			view=li.inflate(R.layout.blogview, null);
		}
		else{
			view=convertView;
		}

		Blog blog=getItem(position);
		if (blog!=null){
			updateBlogView(view, blog);
			
			if (blog.isHaveRetweetedBlog()&& blog.getInReplyBlogText().length()>0){
				updateRetweeteBlogView(view, blog);
			}
			else{
				view.findViewById(R.id.reBlog).setVisibility(View.GONE);
				view.findViewById(R.id.reImage).setVisibility(View.GONE);
			}
		}
		view.setTag(blog);
		return view;
	}

	/**
	 * @param view
	 * @param blog
	 */
	private void updateBlogView(View view, Blog blog) {
		TextView userName=(TextView)view.findViewById(R.id.userName);
		TextView blogText=(TextView)view.findViewById(R.id.blogText);
		WebView profileImage=(WebView)view.findViewById(R.id.profileImage);
		ImageView vImage=(ImageView)view.findViewById(R.id.vImage);
		WebView smallImage=(WebView)view.findViewById(R.id.smallImage);
		TextView sourceText=(TextView)view.findViewById(R.id.sourceText);

		userName.setText(blog.getUser().getScreenName());
		sourceText.setText(context.getString(R.string.from)+blog.getSource());
			
		blogText.setText(blog.getText());
		profileImage.loadUrl(blog.getUser().getProfileImageUrl());
		
		if (!blog.getUser().isVerified())
			vImage.setVisibility(View.INVISIBLE);
		if (blog.getSmallPic().length()>0){
			smallImage.loadUrl(blog.getSmallPic());
		}
		else{
			smallImage.setVisibility(View.GONE);
		}
	}

	/**
	 * @param view
	 * @param blog
	 */
	private void updateRetweeteBlogView(View view, Blog blog) {
		TextView reBlogText=(TextView)view.findViewById(R.id.reBlogText);
		WebView reImage=(WebView)view.findViewById(R.id.reImage);

		if (blog.getInReplyBlogText().length()>0){
			if (blog.getInReplyUserScreenName().length()>0){
				reBlogText.setText(AT+blog.getInReplyUserScreenName()+COLON+blog.getInReplyBlogText());
			}
			else{
				reBlogText.setText(blog.getInReplyBlogText());
			}
		}
		else{
			reBlogText.setVisibility(View.GONE);
		}
		
		if (blog.getRetweetedBlog().getSmallPic().length()>0){
			reImage.loadUrl(blog.getRetweetedBlog().getSmallPic());
		}
		else{
			reImage.setVisibility(View.GONE);
		}
	}

	@Override
	public int getViewTypeCount() {
		return 1;  
	}

	@Override
	public boolean hasStableIds() {
		return false;
	}

	@Override
	public boolean isEmpty() {
		return false;
	}

	@Override
	public void registerDataSetObserver(DataSetObserver observer) {

	}

	@Override
	public void unregisterDataSetObserver(DataSetObserver observer) {

	}

}

 

运行，界面如下图所示：

 

初具雏形，还差的细节包括：表情符未显示，@昵称未高亮显示，URL未展现成链接，图片的外围有白框，图片下载过程中无默认背景。好吧，欲知后事如何，且看下篇分解。

 

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原文链接： http://blog.csdn.net/caowenbin/article/details/6433468