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android ListActivity显示图标实例

程序员文章站 2023-11-18 12:20:34
首先,定义列表中的每一行,这里不是用xml文件定义,而是用一个类定义,checkbox、imageview、textview等控件以addview的方法添加。 复制代码...

首先,定义列表中的每一行,这里不是用xml文件定义,而是用一个类定义,checkbox、imageview、textview等控件以addview的方法添加。

复制代码 代码如下:

//apk列表的一行
class item_apk extends linearlayout{

    public checkbox chk_apk;
    public textview txt_name; 
    public textview txt_flag;
    public imageview img_apk;

    public item_apk(context ctx, string item_name, string item_flag, drawable item_draw)
    {

        super(ctx);
        this.setorientation(horizontal);

        chk_apk = new checkbox(ctx);
        addview(chk_apk,
                new linearlayout.layoutparams((int)(mainactivity.wid_scr*0.2),60));    

        img_apk = new imageview(ctx);
        img_apk.setimagedrawable(item_draw);
        addview(img_apk,
                new linearlayout.layoutparams((int)(mainactivity.wid_scr*0.2),60));

        txt_name = new textview(ctx);
        txt_name.settext(item_name);
        addview(txt_name,
                new linearlayout.layoutparams((int)(mainactivity.wid_scr*0.4),60));

        txt_flag = new textview(ctx);
        txt_flag.settext(item_flag);
        addview(txt_flag,
                new linearlayout.layoutparams((int)(mainactivity.wid_scr*0.2),60));

     }

}

然后,是定义列表,同样,也是用一个类来定义,这里的类继承自baseadapter。

复制代码 代码如下:

// apk列表
class list_apk extends baseadapter{

     private context ctx;
            private list<item_apk> list_data;

    public list_apk(context context){

        ctx = context;
        list_data = new arraylist<item_apk>();

    }

    @override
    public int getcount() {
        // todo auto-generated method stub
        return list_data.size();
    }

    @override
    public object getitem(int arg0) {
        // todo auto-generated method stub
        return list_data.get(arg0);
    }

    @override
    public long getitemid(int arg0) {
        // todo auto-generated method stub
        return list_data.indexof(arg0);
    }

    @override
    public view getview(int position, view convertview, viewgroup parent) {

        item_apk my_item;

        if (convertview==null)
        { 
            my_item = new item_apk(ctx,
                    (string)list_data.get(position).txt_name.gettext(),
                    (string)list_data.get(position).txt_flag.gettext(),
                    list_data.get(position).img_apk.getdrawable()); 
        }
        else
        { 
            my_item = (item_apk)convertview; 
            my_item.txt_name = list_data.get(position).txt_name; 
            my_item.txt_flag = list_data.get(position).txt_flag;
            my_item.img_apk = list_data.get(position).img_apk; 
        } 
        return my_item;

    }

    public void additem(string txt_name, string txt_flag, drawable ico_apk)
    { 
        list_data.add(new item_apk(ctx,txt_name,txt_flag,ico_apk));                
    }

}

最后,是activity的类,这里的activity类的oncreate(bundle savedinstancestate)里面没有setcontentview()方法,取而代之的是setlistadapter()方法。

复制代码 代码如下:

public class apk extends listactivity{

    @override
    protected void oncreate(bundle savedinstancestate) {

        super.oncreate(savedinstancestate);

        list_apk list_ada =  new list_apk(this);

        // 包管理器
        packagemanager pm = getpackagemanager();
        //获取手机内所有应用
        list<packageinfo> pi = pm.getinstalledpackages(0);

        list_ada.additem("应用名称",
                "是否系统应用",
                null); 

        for (int i=0; i<pi.size(); i++){

            packageinfo pii = (packageinfo) pi.get(i);
            string is_sys;
            drawable icon;

            if ((pii.applicationinfo.flags & pii.applicationinfo.flag_system) <= 0)
                is_sys = "否";
            else
                is_sys = "是";

            if (pii.applicationinfo.loadicon(pm)!=null)
                icon = (drawable)pii.applicationinfo.loadicon(pm);
            else
                icon = (drawable) getresources().getdrawable(r.drawable.ic_launcher);

             
            list_ada.additem(string.valueof(pii.applicationinfo.loadlabel(pm)),
                    is_sys,
                    icon);         

        }

        setlistadapter(list_ada);

    }

    @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;
    }

}

整个activity都是由类构成,没有用到一个xml布局文件。
运行效果如下。