Android开发之ListView添加多种布局效果演示

在这个案例中展示的新闻列表，使用到ListView控件，然后在适配器中添加多种布局效果，这里通过重写BaseAdapter类中的 getViewType()和getItemViewType()来做判断，指定ListView列表中指定位置的item加载对应的布局，在 getView中返回对应的视图，之前由于不清楚getViewTypeCount()和getItemViewType()方法，使用得比较少，一直以 为需要添加多个适配器，现在看来当时的想法说明自己见识还不够，哈哈。
第一步：创建放置ListView控件的news_list_listView.xml布局，如下

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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" >
 
    <ListView
        android:id="@+id/news_list_more_layout_listView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true" />
 
</RelativeLayout>

第二步：定义不要在ListView控件中展示新闻列表的布局 效果，在上面的案例中，banner是一张图片和新闻标题，中间是新闻标题、新闻概要和图片，最后是新闻标题和三张新闻图片，这里三个布局分别命名 为：news_banner_item.xml,news_list_item.xml,news_three_img_item.xml

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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="150dp" >
 
    <ImageView
        android:id="@+id/model_news_title_iv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:src="@drawable/demo"
        android:scaleType="fitXY"
        android:contentDescription="@string/news_content_description"/>
 
    <TextView
        android:id="@+id/model_news_title_tv"
        android:layout_width="match_parent"
        android:layout_height="25dp"
        android:layout_alignBottom="@+id/model_news_title_iv"
        android:layout_alignParentLeft="true"
        android:background="@color/list_item_bg_selector"
        android:gravity="center_vertical"
        android:paddingLeft="10dp"
        android:text="@string/display_news" />
 
</RelativeLayout>
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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="wrap_content" >
 
    <ImageView
        android:id="@+id/news_list_profile_image_iv"
        style="@style/weixin_news_list_img_c"
        android:layout_marginRight="@dimen/shadow_width"
        android:contentDescription="@string/news_each_info"
        android:src="@drawable/ic_launcher"
        android:scaleType="fitXY" />
 
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:layout_marginLeft="@dimen/shadow_width"
        android:layout_toLeftOf="@+id/news_list_profile_image_iv"
        android:orientation="vertical"
        android:id="@+id/news_list_item_ll" >
 
        <TextView
            android:id="@+id/news_title_tv"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/rec_tone"
            android:textSize="@dimen/list_cat_size"
            android:textColor="@color/text_black_title" />
 
        <TextView
            android:id="@+id/news_overview_tv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/news_overview_info"
            android:textColor="@color/text_gray_title"
            android:textSize="@dimen/list_dis_tv_size" />
    </LinearLayout>
    <View
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:background="@color/list_item_bg_selector"
        android:layout_below="@+id/news_list_item_ll"
        android:layout_marginTop="4dp"/>
     
</RelativeLayout>
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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="120dp" >
<RelativeLayout
    android:id="@+id/news_more_img_rl"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_below="@+id/news_list_item_text_iv">
    <LinearLayout
        android:id="@+id/news_horizontal_ll"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >
 
        <ImageView
            android:id="@+id/news_list_item_img_one_iv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="5dp"
            android:layout_weight="1"
            android:src="@drawable/ic_launcher" />
 
        <ImageView
            android:id="@+id/news_list_item_img_two_iv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="5dp"
            android:layout_weight="1"
            android:src="@drawable/ic_launcher" />
 
        <ImageView
            android:id="@+id/news_list_item_img_three_iv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="5dp"
            android:layout_weight="1"
            android:src="@drawable/ic_launcher" />
    </LinearLayout>
</RelativeLayout>
    <TextView
        android:id="@+id/news_list_item_text_iv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="@string/display_news"
        android:textColor="@color/text_black_title"
        android:textSize="@dimen/list_cat_size" />
 
</RelativeLayout>

第三步：在NewsMainActivity中获取布局 news_list_listview.xml中的ListView控件，然后添加ListView的适配器 MyNewsBaseAdapter，MyNewsBaseAdapter继承BaseAdapter，重写getViewType、 getItemViewType、getItem、getItemId、getCount和getView方法，其中重点是getViewType和 getItemViewType方法，通过这两个方法判断需要加载的布局，getViewTypeCount返回布局视图数 量，getItemViewType方法加载布局视图。

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    @Override
public int getItemViewType(int position) {
    int p = position;
    if (p == 0) {
        return TYPE_BANNER;//position是ListView中item的ID，指定ID为0的item，加载news_banner_item.xml布局
    } else if (p > 0 && 0 == p % 4) {
        return TYPE_THREE_IMG_ITEM;//加载news_three_img_item.xml
    } else {
        return TYPE_COMMON_LIST_ITEM;//加载news_list_item.xml,news_three_img_item.xml
    }
}
 
@Override
public int getViewTypeCount() {
 
    return 3;
}
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@Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder = null;
        ViewHolder2 viewHolder2 = null;
        ViewHolder3 viewHolder3 = null;
        int type = getItemViewType(position);//获取指定的布局类型
        inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);//布局加载器对象
        if (convertView == null) {
            switch (type) {
            case TYPE_BANNER:
                convertView = inflater.inflate(R.layout.img_text_banner_item,
                        parent, false);
                viewHolder = new ViewHolder();
                viewHolder.bannerImg = (ImageView) convertView
                        .findViewById(R.id.model_news_title_iv);
                viewHolder.bannerTitle = (TextView) convertView
                        .findViewById(R.id.model_news_title_tv);
 
                convertView.setTag(viewHolder);
                break;
            case TYPE_COMMON_LIST_ITEM:
                convertView = inflater.inflate(R.layout.news_list_item, parent,
                        false);
                viewHolder2 = new ViewHolder2();
                viewHolder2.commonImg = (ImageView) convertView
                        .findViewById(R.id.news_list_profile_image_iv);
                viewHolder2.overviewTV = (TextView) convertView
                        .findViewById(R.id.news_overview_tv);
                viewHolder2.titleTV = (TextView) convertView
                        .findViewById(R.id.news_title_tv);
 
                convertView.setTag(viewHolder2);
                break;
            case TYPE_THREE_IMG_ITEM:
                convertView = inflater.inflate(R.layout.more_img_text_item,
                        parent, false);
                viewHolder3 = new ViewHolder3();
 
                viewHolder3.titleTV = (TextView) convertView
                        .findViewById(R.id.news_list_item_text_iv);
                viewHolder3.imgOne = (ImageView) convertView
                        .findViewById(R.id.news_list_item_img_one_iv);
                viewHolder3.imgTwo = (ImageView) convertView
                        .findViewById(R.id.news_list_item_img_two_iv);
                viewHolder3.imgThree = (ImageView) convertView
                        .findViewById(R.id.news_list_item_img_three_iv);
 
                convertView.setTag(viewHolder3);
                break;
            }
        } else {
            switch (type) {
 
            case TYPE_BANNER:
                viewHolder = (ViewHolder) convertView.getTag();
 
                break;
            case TYPE_COMMON_LIST_ITEM:
                viewHolder2 = (ViewHolder2) convertView.getTag();
 
                break;
            case TYPE_THREE_IMG_ITEM:
                viewHolder3 = (ViewHolder3) convertView.getTag();
 
                break;
            }
        }
        // 填充数据到指定的布局文件中
        switch (type) {
        case TYPE_BANNER:      
            viewHolder.bannerImg.setImageResource(R.drawable.demo); //图片从资源中获取
            viewHolder.bannerTitle.setText(entryList.get(position)//entryList是存放新闻消息实体List对象，获取新闻标题
                    .getFull_title());
 
            break;
        case TYPE_COMMON_LIST_ITEM:
            viewHolder2.commonImg.setImageResource(R.drawable.demo);
            viewHolder2.overviewTV
                    .setText(entryList.get(position).getContent());//获取新闻内容
            viewHolder2.titleTV
                    .setText(entryList.get(position).getFull_title());//获取新闻内容
 
            break;
        case TYPE_THREE_IMG_ITEM:
            viewHolder3.titleTV
                    .setText(entryList.get(position).getFull_title());
            viewHolder3.imgOne.setImageResource(R.drawable.demo);
            viewHolder3.imgTwo.setImageResource(R.drawable.demo);
            viewHolder3.imgThree.setImageResource(R.drawable.demo);
 
            break;
        default:
            break;
        }
 
        return convertView;
    }

这里展示部分的源码，完整的源码可以点击这里下载

posted @ 2015-11-04 00:08  我要博客go  阅读(709)  评论(0)  编辑  收藏  举报