AndroidSamplePaper

KeyPoints:

• uses-permission
• Intent Bundle
• AsyncTask
• SimpleAdapter

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.leo.myandroidexam1">
<uses-permission android:name="android.permission.INTERNET"/>
    <application
……

Book

public class Book extends HashMap<String,String> {
    private static final long serialVersionUID = 7701355780902549134L;
    public Book(String title, String author, String review, String price)
    { put("title", title);
        put("author", author);
        put("review", review);
        put("price", price);
    }
    public static List<Book> readBook(String url)
    { List<Book> book = new ArrayList<Book>();
        try {
            JSONArray a = JSONParser.getJSONArrayFromUrl(url);
            for (int i = 0; i<a.length(); i++) {
                JSONObject b = a.getJSONObject(i);
                book.add(new Book(b.getString("Title"),
                        b.getString("Author"),
                        b.getString("Review"),
                        Double.toString(b.getDouble("Price"))));
            }
        } catch (Exception e) {
            Log.e("JSONArray error", e.toString()); }
        return book;
    }
}

MainActivity

public class MainActivity extends AppCompatActivity {

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

        Button button = (Button) findViewById(R.id.button1);
        final EditText et = (EditText) findViewById(R.id.editText1);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //Intent intent = new Intent(this,ListBooks.class);
                Intent intent = new Intent(getApplicationContext(), ListBooks.class);
                String target = et.getText().toString();
                intent.putExtra("target", target);
                startActivity(intent);
            }

        });
    }
}

ListBooks

public class ListBooks extends ListActivity {

    static String URL = "http://172.17.251.222/books/Search/";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        String target = getIntent().getExtras().getString("target");

        new AsyncTask<String, Void, List<Book>>() {
            @Override
            protected List<Book> doInBackground(String... params) {
                return Book.readBook(params[0]);
            }

            @Override
            protected void onPostExecute(List<Book> result) {
                SimpleAdapter adapter = new SimpleAdapter(getApplicationContext(), result,
                        android.R.layout.simple_list_item_2,
                        new String[]{"title", "author"},
                        new int[]{android.R.id.text1, android.R.id.text2});
                setListAdapter(adapter);
            }
        }.execute(URL + target);

    }

    protected void onListItemClick(ListView l, View v,
                                   int position, long id) {
        Book item = (Book) getListAdapter().getItem(position);
        Intent i = new Intent(this, Review.class);
        i.putExtra("Book", item);
        startActivity(i);
    }
}

Review

public class Review extends AppCompatActivity {

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

        TextView tv = (TextView)findViewById(R.id.textView1);
        HashMap<String, String> book = (HashMap<String, String>) getIntent().getExtras().get("Book");

        tv.setText((String) book.get("decription"));
    }
}

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拓展

ArrayAdapter

public class MainActivity extends ListActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        String[] values = {"Humour", "History", "Children", "Fiction", "Romance", "Cooking"};
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1, values);
        setListAdapter(adapter);
    }
    
    protected void onListItemClick(ListView l, View v,
                                   int position, long id) {
        String category = (String) getListAdapter().getItem(position);
        Intent intent = new Intent(this, BooklistActivity.class);
        intent.putExtra("Category", category);
        startActivity(intent);
    }
}

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MyAdapter

public class MyAdapter extends ArrayAdapter<String> {

    private List<String> items;
    int resource; //layout

    public MyAdapter(Context context, int resource, List<String> items) {
        super(context, resource, items);
        this.resource = resource;  //for every row
         this.items = items;
    }

    @Override  //?time to form list/row adapter for list ot use
    public View getView(int position, View convertView, ViewGroup parent) {
        LayoutInflater inflater = (LayoutInflater) getContext()
                .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        View v = inflater.inflate(resource, null);  //inflator take layout
        final String eid = items.get(position);
        if (eid != null) {
            TextView e = (TextView) v.findViewById(R.id.textView); //hold id
            e.setText(eid);
            //set
            final ImageView image = (ImageView) v.findViewById(R.id.imageView2); //hold tomnier of the pic
            new AsyncTask<Void, Void, Bitmap>() {
                @Override
                protected Bitmap doInBackground(Void... params) {
                    return Employee.getPhoto(false,eid);
                }
                @Override
                protected void onPostExecute(Bitmap result) {
                    image.setImageBitmap(result);
                }
            }.execute();
        }//what you have in the row
        //evevry things else is generic based on that your layout is definde
        return v;  //return this view have in side is filled above
    }
}

MainActivity

public class MainActivity extends ListActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
//        StrictMode.setThreadPolicy(StrictMode.ThreadPolicy.LAX);  //

        new AsyncTask<Void, Void, List<String>>() {
            @Override
            protected List<String> doInBackground(Void... params) {
                return Employee.list();
            }
            @Override
            protected void onPostExecute(List<String> result) {
                MyAdapter adapter = new MyAdapter(MainActivity.this, R.layout.row, result);
                setListAdapter(adapter);
            }
        }.execute();

    }

    @Override
    protected void onListItemClick(ListView l, View v,
                                   int position, long id) {
        String item = (String) getListAdapter().getItem(position);
        Intent intent = new Intent(this, EmpDetailsActivity.class);
        intent.putExtra("eid", item);  //pass id
        startActivity(intent);
    }
}

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