建立自己的TextView和ImageView的組合View類

package hi.braincol.local.filebrowser.icontextlist;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import android.graphics.drawable.Drawable;

//IconText類，該類中主要有兩個數據成員：String mText 和 Drawable mIcon。

//並實現了泛型接口Comparable<?>，實現這個接口的目的是為了

//讓類似於"List<IconText> Entries = new ArrayList<IconText>();"

//的對象Entries具有排序功能"Collections.sort(Entries);"

public class IconText implements Comparable<IconText>{

    private String mText = " ";

    private Drawable mIcon;

    private boolean mSelectable = true;

    public IconifiedText(String text, Drawable bullet) {

        mIcon = bullet;

        mText = text;

    }

    public boolean isSelectable() {

        return mSelectable;

    }

    public void setSelectable(boolean selectable) {

        mSelectable = selectable;

    }

    //獲取Text

    public String getText() {

        return mText;

    }

    //設置Text

    public void setText(String text) {

        mText = text;

    }

    //獲取Icon

    public void setIcon(Drawable icon) {

        mIcon = icon;

    }

    //設置Icon

    public Drawable getIcon() {

        return mIcon;

    }

    //Comparable<?>接口中的方法

    @Override

    public int compareTo(IconText other) {

        if(this.mText != null)

            return this.mText.compareTo(other.getText()); 

        else 

            throw new IllegalArgumentException();

    }

}

package hi.braincol.local.filebrowser.icontextlist;

import android.content.Context;

import android.graphics.drawable.Drawable;

import android.util.Log;

import android.view.Gravity;

import android.widget.ImageView;

import android.widget.LinearLayout;

import android.widget.TextView;

//創建一個text和Icon組合的view子類

//繼承與LinerLayout表示兩個IconTextView中的TextView和ImageView之間是線性布局關係。

public class IconTextView extends LinearLayout {

    //類中的兩個私有成員，Text和Icon

    //IconifiedTextView中的兩個子View。由TextView和ImageView組合成一個新的View。

    private TextView mText;

    private ImageView mIcon;

    public IconifiedTextView(Context context, IconText aIconText) {

        super(context);

        /* First Icon and the Text to the right (horizontal),

         * not above and below (vertical) */

        //設置IconifiedTextView為水平線性布局

        this.setOrientation(HORIZONTAL);

        //垂直居中對齊

        this.setGravity(Gravity.CENTER_VERTICAL);

        //添加ImageView

        mIcon = new ImageView(context);

        mIcon.setImageDrawable(aIconText.getIcon());

        // left, top, right, bottom

        mIcon.setPadding(0, 2, 5, 2); // 5px to the right

        /* At first, add the Icon to ourself

         * (! we are extending LinearLayout) */

        addView(mIcon,  new LinearLayout.LayoutParams(

                LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));

        //添加TextView， 由於先添加ImageView後添加TextView，所以 ICON 在前 Text 在後。

        mText = new TextView(context);

        mText.setText(aIconText.getText());

        /* Now the text (after the icon) */

        mText.setTextSize(17);

        mText.setPadding(5,2,2,0);

        //mText.setGravity(CENTER_VERTICAL);

        addView(mText, new LinearLayout.LayoutParams(

                LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

    }

    //設置TextView的Text內容

    public void setText(String words) {

        //Log.i("test","setText  "+words);

        mText.setText(words);

    }

    //設置ImageView的Icon圖標

    public void setIcon(Drawable bullet) {

        //Log.i("test","setIcon  ");

        mIcon.setImageDrawable(bullet);

    }

}

package hi.braincol.local.filebrowser.icontextlist;

import java.util.ArrayList;

import java.util.List;

import android.content.Context;

import android.util.Log;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

//創建一個由IconText組成的ListAdapter。

public class IconTextListAdapter extends BaseAdapter {

    /** Remember our context so we can use it when constructing views. */

    private Context mContext;

    //創建一個數組適配器，適配器中每個元素為IconText

    private List<IconText> mItems = new ArrayList<IconText>();

    public IconTextListAdapter(Context context) {

        mContext = context;

    }

    //向適配器內增加元素

    public void addItem(IconText it) { mItems.add(it); }

    //設置適配器

    public void setListItems(List<IconText> lit) { mItems = lit; }

    /** @return The number of items in the List<IconText> mItems*/

    public int getCount() { return mItems.size(); }

    //獲取positon指定位置的IconifiedText元素

    public Object getItem(int position) { return mItems.get(position); }

    public boolean areAllItemsSelectable() { return false; }

    //判斷適配器內某個元素是否被選中

    public boolean isSelectable(int position) { 

        //Log.i("braincol","isSelectable");

        return mItems.get(position).isSelectable();

    }

    /** Use the array index as a unique id. */

    public long getItemId(int position) {

        return position;

    }

    //外部的類內的方法通過調用setListAdapter(IconTextListAdapter obj)

    //實現將IconTextListAdapter作為Activtiy的顯示(布局)。

    //在顯示之前係統會調用getView這個函數來獲得適配器內的每個元素的顯示方式（內容）。

    //每個元素的顯示都會調用getView這個函數，也就是在顯示時有多少個元素就會調用多少次getView

    /** @param convertView The old view to overwrite, if one is passed

     * @returns a IconTextView that holds wraps around an IconText */

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

        Log.i("braincol","getView");

        //每個IconText的顯示方式為IconTextView。

        IconTextView btv;

        if (convertView == null) {

            btv = new IconTextView(mContext, mItems.get(position));

        } else { // Reuse/Overwrite the View passed

            // We are assuming(!) that it is castable! 

            btv = (IconTextView) convertView;

            btv.setText(mItems.get(position).getText());

            btv.setIcon(mItems.get(position).getIcon());

        }

        return btv;

    }

}

...

List<IconText> entries = new ArrayList<IconText>(); 

String text=" ";

Drawable icon = null;

...

for(...){

    ...

    text="xxx";

    icon=getResources().getDrawable(R.drawable.xxxx);

    ...

    //向ArrayList中添加元素

    entries.add(new IconifiedText(text,icon);    

    ...

}

...

//排序，entries之所以能使用Collections.sort來排序，

//是因為IconText 實現了 Comparable<IconText>接口

Collections.sort(entries);

//新建一個IconifiedTextListAdapter對象

IconTextListAdapter itla = new IconTextListAdapter(this);

//設置itla的內容(元素)。

itla.setListItems(entries);

//provide the cursor for listview

//將itla的每個元素都描繪(顯示)在activity上。

this.setListAdapter(itla);

...