Android 项目实战:应用管理器Ⅰ(数据)

了解应用管理器的项目概况和功能需求

(从数据开始做)

掌握PackageManager的用法

掌握PackageInfo的常用属性

掌握Application的常用属性和方法

学会实体类的编写(工具类)

完成项目的创建和数据测试

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版本名为字符串,版本号为数字.

开发实体类:1.在原包下New一个新包entity

                   2.在entity下New一个Java Class -- AppInfo

/**
 * Created by Administrator on 2018/8/14.
 * 实体类:应用的信息
 */

public class AppInfo {

    /** 包名 */
    public String packageName;
    /** 版本名 */
    public String versionName;
    /** 版本号 */
    public int versionCode;
    /** 第一次安装时间 */
    public long insTime;
    /** 更新时间 */
    public long updTime;
    /** 程序名 */
    public String appName;
    /** 图标 */
    public Drawable icon;
    /** 字节大小 */
    public long byteSize;
    /** 大小 */
    public String size;

    @Override                            //Alt+Insert选择toString()
    public String toString() {
        return "\nAppInfo{" +
                "packageName='" + packageName + '\'' +
                ", versionName='" + versionName + '\'' +
                ", versionCode=" + versionCode +
                ", insTime=" + insTime +
                ", updTime=" + updTime +
                ", appName='" + appName + '\'' +
                ", icon=" + icon +
                ", byteSize=" + byteSize +
                ", size='" + size + '\'' +
                '}';
    }
}

建工具包(放工具类:跟整个项目,视图,前台没有太多联系可以独立出来的方法进行整合) :          1.在原包下New一个新包util

2.在util下New一个Java Class -- Utils

/**
 * Created by Administrator on 2018/8/14.
 * 工具类
 */

public class Utils {

    public static List<AppInfo> getAppList(Context context){
        // 返回值集合
        List<AppInfo> list = new ArrayList<AppInfo>();
        // 实例化包管理器
        PackageManager pm = context.getPackageManager();
        // 获取所有已经安装的应用信息
        List<PackageInfo> pList = pm.getInstalledPackages(0);  //0为不加任何过滤条件.放回全部的安装信息
        // 遍历集合
        for(int i = 0; i<pList.size(); i++){
            PackageInfo PackageInfo = pList.get(i);  //拿到元素
            //把实体类实例化出来,把元素对应放入(填充实体类)
            AppInfo app = new AppInfo();
            app.packageName = PackageInfo.packageName;  //属性值的传递
            app.versionName = PackageInfo.versionName;
            app.versionCode = PackageInfo.versionCode;
            app.insTime = PackageInfo.firstInstallTime;
            app.updTime = PackageInfo.lastUpdateTime;
            //获取应用名
            app.appName = (String) PackageInfo.applicationInfo.loadLabel(pm);
            //获取图标
            app.icon = PackageInfo.applicationInfo.loadIcon(pm);
            //计算程序的大小(首先获得安装包的绝对路径,文件夹位置)
            String dir = PackageInfo.applicationInfo.publicSourceDir;       //定义临时变量,接收文件夹路径
            long byteSize = new File(dir).length();
            app.byteSize = byteSize;   //  实际大小
            app.size = getSize(byteSize);  //  格式化好的大小
            //信息装入了实体类,但还未装入List集合
            list.add(app);
        }

        return list;
    }

    public static String getSize(long size){  //DecimalFormat格式化
        return new DecimalFormat("0.##").format(size * 1.0/(1024*1024));
    }
}

Java代码

public class MainActivity extends AppCompatActivity {

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

        //用集合接收传回的返回值.获取数据
        List<AppInfo> list = Utils.getAppList(this);
        Log.i("srq","list="+list.toString());
    }
}

转换时间

Utils类中加

public static String getTime(long millis){  //将毫秒数转化为日期格式的工具方法
    Date date = new Date(millis);   //将毫秒数转化为日期对象
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    return sdf.format(date);
}

改动AppInfo中

@Override
public String toString() {
    return "\nAppInfo{" +
            "packageName='" + packageName + '\'' +
            ", versionName='" + versionName + '\'' +
            ", versionCode=" + versionCode +
            ", insTime=" + Utils.getTime(insTime) +
            ", updTime=" + Utils.getTime(updTime) +
            ", appName='" + appName + '\'' +
            ", icon=" + icon +
            ", byteSize=" + byteSize +
            ", size='" + size + '\'' +
            '}';
}

1.在原包下New一个新包adapter

2.在adapter下New一个Java Class -- MyAdapter

public class MyAdapter extends BaseAdapter {

    List<AppInfo> list;
    LayoutInflater inflater;


    public MyAdapter(Context context) {
        this.inflater = LayoutInflater.from(context);
    }

    public void setList(List<AppInfo> list) {
        this.list = list;
    }

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

    @Override
    public Object getItem(int position) {
        return list.get(position);
    }

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

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;

        if(convertView == null) {
            convertView = inflater.inflate(R.layout.item, null);
            holder = new ViewHolder();
            holder.logo = (ImageView) convertView.findViewById(R.id.logo);
            holder.title = (TextView) convertView.findViewById(R.id.title);
            holder.version = (TextView) convertView.findViewById(R.id.version);
            holder.size = (TextView) convertView.findViewById(R.id.size);
            holder.btn = (Button) convertView.findViewById(R.id.btn);
            convertView.setTag(holder);
        }else{
            holder = (ViewHolder) convertView.getTag();
        }

        AppInfo app = list.get(position);  //list得到的每一个项就是实体类对象
        holder.logo.setImageDrawable(app.icon);
        holder.title.setText(app.appName);
        holder.version.setText(app.versionName);
        holder.size.setText(app.size + "M");

        
        return convertView;
    }

    public class ViewHolder{
        ImageView logo;
        TextView title;
        TextView version;
        TextView size;
        Button btn;
    }
}

colors.xml

<resources>
    <color name="transparent">#00000000</color>
    <color name="choose">#ff0febff</color>
</resources>

drawable -- item_selector.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:drawable="@color/transparent" android:state_pressed="false"/>
    <item android:drawable="@color/choose" android:state_pressed="true"/>

</selector>

drawable -- btn_selector.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:drawable="@drawable/btn_bg2" android:state_pressed="false"/>
    <item android:drawable="@drawable/btn_bg_p" android:state_pressed="true"/>

</selector>

item.xml

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:descendantFocusability="blocksDescendants"
    >

    <!--行布局-->
    <RelativeLayout
        android:id="@+id/box"

        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="5dp"
        android:layout_marginTop="5dp"
        android:layout_marginRight="5dp"
        android:padding="5dp"
        >

        <ImageView
            android:id="@+id/logo"
            android:layout_width="70dp"
            android:layout_height="70dp"
            android:src="@drawable/icon_music"
            android:layout_centerVertical="true"/>


        <Button
            android:id="@+id/btn"
            android:layout_width="66dp"
            android:layout_height="30dp"
            android:text="卸载"
            android:textColor="#fff"
            android:textSize="14sp"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:background="@drawable/btn_selector"
             />

        <!--文字说明的部分-->
       <LinearLayout
           android:id="@+id/textbox"
           android:layout_width="match_parent"
           android:layout_height="70dp"
           android:layout_toRightOf="@id/logo"
           android:layout_toLeftOf="@id/btn"

           android:orientation="vertical">

           <TextView
               android:id="@+id/title"
               android:layout_width="wrap_content"
               android:layout_height="wrap_content"
               android:text="千千静听"
               android:textSize="16sp"
               android:layout_marginTop="3dp"/>

           <TextView
               android:id="@+id/version"
               android:layout_width="wrap_content"
               android:layout_height="wrap_content"
               android:text="版本: 1.0"
               android:textSize="12sp"
               android:textColor="#999"
               android:layout_marginTop="6dp"/>

           <TextView
               android:id="@+id/size"
               android:layout_width="wrap_content"
               android:layout_height="wrap_content"
               android:text="大小: 18.05M"
               android:textSize="12sp"
               android:textColor="#999"
               android:layout_marginTop="6dp"/>


           </LinearLayout>


    </RelativeLayout>

</RelativeLayout>

main.xml

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
   >


    <!--listview的标签-->
    <ListView
        android:id="@+id/lv_main"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:listSelector="@drawable/item_selector"

        />

</RelativeLayout>

Java代码

public class MainActivity extends Activity {

    ListView lv;
    List<AppInfo> list;
    MyAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        //拿到ListView
        lv = (ListView) findViewById(R.id.lv_main);
        //数据源
        list = Utils.getAppList(this);
        //适配器
        adapter = new MyAdapter(this);
        adapter.setList(list);
        //关联
        lv.setAdapter(adapter);

        Log.i("srq","list="+list.toString());
    }

}

改动MyAdapter(测试用)

AppInfo app = list.get(position);  
holder.logo.setImageDrawable(app.icon);
holder.title.setText(app.appName);
holder.version.setText(app.versionName + " "+ Utils.getTime(app.insTime));
holder.size.setText(app.size + "M" + " "+Utils.getTime(app.updTime));