Android复习代码

Android重点代码

图片下载

public class ImageDownTask extends AsyncTask <String,void,Bitmap>
    protected Bitmap doInBackground(String....String){
    	Bitmap bitmap = null;
    	String url = string[0];
    	URLConnection conn;
    	InputStream is;
    	try{
            conn = new URL(url).openConnection();
            is = conn.getInputStream();
            BufferedInputStream bis = new BufferedInputStream();
            bitmap = BitmapFactory.decodeStream(bis);
            is.close();
            conn.close();
        }catch(MalformedURLException e){
            e.printStackTrace();
        }catch(IOException e){
            e.printStackTrace();
        }
    	return bitmap;
	}

保存到XML文件和读取XML文件

private boolean save_userMes(Context context,String username,String paswd){
    SharedPreferences sharedPreferences = context.getSharedPreferences("user_mes",MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPreferences.edit();
    editor.putString("username",username);
    editor.putString("paswd",paswd); 
    editor.commit();
    return true;
}

private Map<String,String> getuser_mes(Context context){
    SharedPreferences sharedPreferecnces = context.getSharedPreferences("user_mes",MODE_PRIVATE);
    String username = sharedPrederences.getString("username",null);
    String paswd = sharedPrederences.getStrinf("paswd",null);
    Map<String,String> user = new HashMap<String,String>();
    user.put("username",username);
    user.put("paswd",paswd);
    return user;
}

基于ArrayAdapter创建ListView

public void Arrsylist(){
    ListView listView = (ListView)findViewById(R.id.listView1);
    
    String[] arr = {"章节1","章节2","章节3"};
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(This,android.R.layout.simple_expandable_list_item_1,arr);
    listView.setAdapater();
}

使用线程持续输出

public class testService extends Service{
    boolean running = true;
    public void onCreate(){
        super.onCreate();
	}
    
    public int onStartCommand(Intent intent,int flags,int startId){
        new Tread(){
            public void run(){
                super.run();
                while(running == true){
                    System.out.println("abc");
                    i ++;
                   	try{
                        sleep(1000);
                    }catch(InterrutedException e){
                        e.printStackTrace();
                    }
                }
            }
        }.start();
        retrun super.onStartCommand(intant,flags,startId);
    }
}