Android ListView操作處理

大家在Android開發過程中用的比較頻繁應該就是ListView、GridView吧，不過ListView、GridView不僅僅只是用來作爲顯示而已，有時候可能需要來點擊列表之中某一項把當前這一項中所顯示數據給獲取出來，或是改變當前這一項的數據、界面顯示，這都是比較常見的。

那麼該如何做呢？（難道給控件實現一個點擊事件直接在點擊事件裏面獲取控件顯示的數據、直接改變該控件界面顯示，這樣是行不通的，往往會出現數據錯亂、顯示不正常，因爲都沒有明確指定要處理的是哪一項) ，在Adapter的getView方法中，應該明確去指定操作數據而不應該是直接操作控件，再用數據來操作控件，數據纔是最真實的。

下面用ListView作爲示例實現上述的操作：

效果圖：

在res的drawable-hdpi文件下添加需要用到的一些圖片

1.首先在主activity_main界面上添加一個ListView作爲顯示

<pre name="code" class="html"><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"
    tools:context="com.it.listviewdemo.MainActivity" >

    <ListView
        android:id="@+id/main_lv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_margin="10dp"
        android:dividerHeight="0dp"
        android:divider="#f6f6f6"
        android:scrollbars="none"
        android:listSelector="@android:color/transparent" />

</RelativeLayout>

2.接着新建一個activity_qzone作爲ListView每項要顯示的佈局

<?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="wrap_content"
    android:orientation="vertical" >

    <!-- 主顯示佈局 -->
    <LinearLayout
        android:id="@+id/qzone_main_ll"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >

        <!-- 第一部分佈局 -->
        <LinearLayout
            android:layout_margin="10dp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal" >
            <!-- 頭像 -->
            <ImageView
                android:id="@+id/qzone_head_iv"
                android:layout_width="50dp"
                android:layout_height="50dp"
                android:scaleType="centerCrop"
                android:src="@drawable/hao123" />
            <LinearLayout
                android:layout_marginLeft="10dp"
                android:layout_marginRight="10dp"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical" >
                <!-- 暱稱 -->
                <TextView
                    android:id="@+id/qzone_name_tv"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:textSize="18sp"
                    android:text="hao123" />
                <!-- 時間 -->
                <TextView
                    android:id="@+id/qzone_time_tv"
                    android:layout_marginTop="10dp"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:textSize="12sp"
                    android:text="今天07:00" />
            </LinearLayout>
        </LinearLayout>

        <!-- 第二部分佈局 -->
        <LinearLayout
            android:layout_margin="10dp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:gravity="center_vertical"
            >
            <!-- 內容 -->
            <TextView
                android:id="@+id/qzone_contents_tv"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textSize="15sp"
                android:lineSpacingExtra="2dp"
                android:text="只是第一條顯示數據而已."
                />
        </LinearLayout>

        <!-- 第三部分佈局 -->
        <LinearLayout
            android:layout_margin="10dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:gravity="center_vertical"
            >
            <!-- 圖片 -->
            <ImageView
                android:id="@+id/qzone_picture_iv"
                android:layout_width="200dp"
                android:layout_height="200dp"
                android:scaleType="centerCrop"
                android:src="@drawable/hao123"
                />
        </LinearLayout>

    </LinearLayout>

    <!-- 功能實現佈局 -->
    <LinearLayout
        android:layout_margin="10dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:layout_gravity="right"
        >
        <!-- 贊功能 -->
        <ImageView
            android:id="@+id/qzone_like_iv"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:scaleType="centerCrop"
            android:src="@drawable/preview_like_icon_disable"
            />
    </LinearLayout>

    <!-- 分割線 -->
    <View
        android:layout_width="match_parent"
        android:layout_height="3dp"
        android:background="#808080" />

</LinearLayout>

上面的佈局：分爲了兩大塊(主顯示、功能實現)

 1.主要是爲了方便看

 2.也是爲了後面處理點擊比較方便

3. 根據上面activity_qzone界面顯示的（頭像、暱稱、時間、內容、圖片、點贊）， 創建對應的實體類

public class Qzone implements Serializable {

    private static final long serialVersionUID = -6074203749103731484L;
    private Integer head;       //頭像
    private String name;        //暱稱
    private String time;        //時間
    private String contents;    //內容
    private Integer picture;    //圖片
    private boolean like;       //贊功能

    public Qzone() {

    }

    public Qzone(Integer head, String name, String time, String contents,
            Integer picture, boolean like) {
        super();
        this.head = head;
        this.name = name;
        this.time = time;
        this.contents = contents;
        this.picture = picture;
        this.like = like;
    }

    public Integer getHead() {
        return head;
    }
    public void setHead(Integer head) {
        this.head = head;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getTime() {
        return time;
    }
    public void setTime(String time) {
        this.time = time;
    }
    public String getContents() {
        return contents;
    }
    public void setContents(String contents) {
        this.contents = contents;
    }
    public Integer getPicture() {
        return picture;
    }
    public void setPicture(Integer picture) {
        this.picture = picture;
    }
    public boolean isLike() {
        return like;
    }
    public void setLike(boolean like) {
        this.like = like;
    }

}

4. Activity代碼

MainActivity：

public class MainActivity extends Activity {

    private ListView lv_main;
    private List<Qzone> list;
    private QzoneAdapter mAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initData();
        initButton();
    }

    private void initButton() {
        // TODO Auto-generated method stub
        lv_main = (ListView) findViewById(R.id.main_lv);
        lv_main.setAdapter(mAdapter);
    }

    /**
     * 本地數據（測試）
     */
    private void initData() {
        // TODO Auto-generated method stub
        list = new ArrayList<Qzone>();
        list.add(new Qzone(R.drawable.hao123, "hao123", "今天07:00", "只是第一條顯示數據而已.", R.drawable.hao123, false));
        list.add(new Qzone(R.drawable.baidu, "baidu", "今天08:00", "只是第二條顯示數據而已.", R.drawable.baidu, false));
        list.add(new Qzone(R.drawable.wy163, "wy163", "今天09:00", "只是第三條顯示數據而已.", R.drawable.wy163, false));
        list.add(new Qzone(R.drawable.weibo, "weibo", "今天10:00", "只是第四條顯示數據而已.", R.drawable.weibo, false));
        list.add(new Qzone(R.drawable.douban, "douban", "今天11:00", "只是第五條顯示數據而已.", R.drawable.douban, false));
        list.add(new Qzone(R.drawable.taobao, "taobao", "今天12:00", "只是第六條顯示數據而已.", R.drawable.taobao, false));
        list.add(new Qzone(R.drawable.youku, "youku", "今天13:00", "只是第七條顯示數據而已.", R.drawable.youku, false));
        list.add(new Qzone(R.drawable.qzone, "qzone", "今天14:00", "只是第八條顯示數據而已.", R.drawable.qzone, false));
        list.add(new Qzone(R.drawable.renren, "renren", "今天15:00", "只是第九條顯示數據而已.", R.drawable.renren, false));
        list.add(new Qzone(R.drawable.sina, "sina", "今天16:00", "只是第十條顯示數據而已.", R.drawable.sina, false));
        mAdapter = new QzoneAdapter(this, list);
    }
}

MainActivity顯示的是activity_main.xml

QzoneActivity:

public class QzoneActivity extends Activity {

    private Qzone qzone;

    private ImageView iv_head;
    private TextView tv_name;
    private TextView tv_time;
    private TextView tv_contents;
    private ImageView iv_picture;
    private ImageView iv_like;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_qzone);
        initButton();
        initData();
    }

    private void initButton() {
        // TODO Auto-generated method stub
        iv_head = (ImageView) findViewById(R.id.qzone_head_iv);
        tv_name = (TextView) findViewById(R.id.qzone_name_tv);
        tv_time = (TextView) findViewById(R.id.qzone_time_tv);
        tv_contents = (TextView) findViewById(R.id.qzone_contents_tv);
        iv_picture = (ImageView) findViewById(R.id.qzone_picture_iv);
        iv_like = (ImageView) findViewById(R.id.qzone_like_iv);
    }

    /**
     * 獲取到傳遞過來的數據，顯示到相對應的控件上
     */
    private void initData() {
        // TODO Auto-generated method stub
        qzone = (Qzone) getIntent().getSerializableExtra("Qzone");
        if(qzone != null){
            iv_head.setImageResource(qzone.getHead());
            tv_name.setText(qzone.getName());
            tv_time.setText(qzone.getTime());
            tv_contents.setText(qzone.getContents());
            iv_picture.setImageResource(qzone.getPicture());
            iv_like.setImageResource(qzone.isLike() ? R.drawable.like_icon : R.drawable.like_icon_disable);
        }
    }
}

QzoneActivity顯示的是activity_qzone.xml

5. Adapter適配器

public class QzoneAdapter extends BaseAdapter implements OnClickListener {

    private Activity act;
    private LayoutInflater inflater;
    private ViewHolder holder;
    private List<Qzone> list;

    public QzoneAdapter(Activity act, List<Qzone> list) {
        this.act = act;
        this.inflater = act.getLayoutInflater();
        this.list = list;
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return list.size();
    }

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return list.get(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
        if(convertView == null){
            convertView = inflater.inflate(R.layout.activity_qzone , null);
            holder = new ViewHolder();
            holder.ll_main = (LinearLayout) convertView.findViewById(R.id.qzone_main_ll);
            holder.iv_head = (ImageView) convertView.findViewById(R.id.qzone_head_iv);
            holder.tv_name = (TextView) convertView.findViewById(R.id.qzone_name_tv);
            holder.tv_time = (TextView) convertView.findViewById(R.id.qzone_time_tv);
            holder.tv_contents = (TextView) convertView.findViewById(R.id.qzone_contents_tv);
            holder.iv_picture = (ImageView) convertView.findViewById(R.id.qzone_picture_iv);
            holder.iv_like = (ImageView) convertView.findViewById(R.id.qzone_like_iv);
            convertView.setTag(holder);
        }else{
            holder = (ViewHolder) convertView.getTag();
        }
        Qzone qzone = list.get(position);
        holder.iv_head.setImageResource(qzone.getHead());
        holder.tv_name.setText(qzone.getName());
        holder.tv_time.setText(qzone.getTime());
        holder.tv_contents.setText(qzone.getContents());
        holder.iv_picture.setImageResource(qzone.getPicture());

        //  贊圖標顯示
        holder.iv_like.setImageResource(qzone.isLike() ?  R.drawable.like_icon : R.drawable.like_icon_disable);

        //  主顯示佈局設置一個標示, 實現點擊
        holder.ll_main.setTag(position);
        holder.ll_main.setOnClickListener(this);

        //  贊功能控件設置一個標示, 實現點擊
        holder.iv_like.setTag(position);
        holder.iv_like.setOnClickListener(this);

        return convertView;
    }

    private class ViewHolder{
        LinearLayout ll_main;   //  主顯示佈局
        ImageView iv_head;      //  頭像
        TextView tv_name;       //  暱稱
        TextView tv_time;       //  時間
        TextView tv_contents;   //  內容
        ImageView iv_picture;   //  圖片
        ImageView iv_like;      //  贊圖標
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {
        //  主顯示佈局點擊事件處理(獲取之前設置的標示)
        case R.id.qzone_main_ll:
            IntentMethod((Integer) v.getTag());
            break;
        //  贊功能控件點擊事件處理(獲取之前設置的標示)
        case R.id.qzone_like_iv:
            LikeMethod((Integer) v.getTag());
            break;

        default:
            break;
        }
    }

    /**
     * 跳轉功能實現
     * @param position
     */
    private void IntentMethod(int position) {
        Toast.makeText(act, "進入"+list.get(position).getName()+"詳細界面", Toast.LENGTH_SHORT).show();
        Intent intent = new Intent(act, QzoneActivity.class);
        intent.putExtra("Qzone", list.get(position));
        act.startActivity(intent);
    }

    /**
     * 贊功能實現
     * @param position
     */
    private void LikeMethod(int position) {
        list.get(position).setLike(!list.get(position).isLike());
        notifyDataSetChanged(); //刷新列表

        Qzone qzone = list.get(position);
        Toast.makeText(act, qzone.isLike() ? "點贊"+qzone.getName() : qzone.getName()+"取消贊", Toast.LENGTH_SHORT).show();
    }

}

在顯示的贊圖標的時候，利用數據作爲條件使用三目運算符去判斷要顯示的圖標

1. 在getView方法要執行某種操作，一般給控件設置一個Tag(標示) ,賦值position

 控件.setTag(position);

2. position就是getView方法的參數，其實這個參數對應着ListView列表的Item(項)位置

public View getView(int position, View convertView, ViewGroup parent)

3.爲控件設置一個點擊事件，然後就可以在點擊事件方法獲取到剛纔設置的Tag(項)位置

int position = (Integer) v.getTag();