Question

Json FUnction能够解析数据并在sq-lite数据库中插入值

for (int i = 0; i < jArray6.length(); i++) {
                    catagoryid = 5;
                    json_data = jArray6.getJSONObject(i);
                    // news_id = Integer.parseInt((json_data.getString("news_id")));
                    news_id = Double.parseDouble(json_data.getString("news_id"));
                    news_title = json_data.getString("news_title");
                    imagepath = json_data.getString("imagepath").trim().getBytes();
                    news_short_description = json_data
                            .getString("news_short_description");
                    news_detail = json_data.getString("news_detail_description");
                    news_date = json_data.getString("news_date");
                    website_link = json_data.getString("website_link").trim();
                    dh = new DBhelper(TaxMann.this);
                    record_id = dh.AddMsgt1(news_id, catagoryid, news_title,
                            imagepath, news_short_description, news_date,
                            news_detail, website_link);
                }

这是我的数据库类函数

@Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        db.execSQL("CREATE TABLE " + topstories
                + "(_id INTEGER PRIMARY KEY AUTOINCREMENT," + news_id
                + " double, " + catagory_Id + " integer," + news_title
                + " text," + imagepath + " BLOB, " + short_description
                + " text, " + news_date + " text, " + detailed_news + " text, "
                + website_link + " text)");
        db.execSQL("CREATE TABLE " + savednews
                + "(_id INTEGER PRIMARY KEY AUTOINCREMENT," + news_id
                + " double," + news_title + " text," + imagepath + " BLOB,  "
                + detailed_news + " text)");
        db.execSQL("CREATE TABLE " + date
                + "(_id INTEGER PRIMARY KEY AUTOINCREMENT," + modified_date
                + " integer)");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        db.execSQL("drop table if exists " + topstories);
        db.execSQL("drop table if exists " + savednews);
        db.execSQL("drop table if exists " + date);
        onCreate(db);
    }

    // records for newstable

public int AddMsgt1(double newsid, Integer cat_id, String title,
        byte[] image, String desc, String date, String detail,
        String website) {
    db = this.getWritableDatabase();
    ContentValues cv = new ContentValues();
    cv.put(news_id, newsid);
    cv.put(catagory_Id, cat_id);
    cv.put(news_title, title);
    cv.put(imagepath, image);
    cv.put(short_description, desc);
    cv.put(news_date, String.valueOf(date));
    cv.put(detailed_news, detail);
    cv.put(website_link, website);

    long record_id = db.insert(topstories, news_title, cv);
    db.close();
    return (int) record_id;
}

public Cursor fetchtitle(int catagoryid) {
            SQLiteDatabase db1 = this.getReadableDatabase();
            cursor = db1.query(topstories,
                    new String[] { "_id", "news_title", "imagepath",
                            "short_description", "news_date", "detailed_news", },
                    "catagory_id=" + catagoryid, null, null, null, null, null);
            return cursor;
        }

从这里我可以显示标题和描述，但我无法显示图像

public void simple_ad(Cursor cursor,int category_id)
    {
        dh = new DBhelper(this);
        ListView list = (ListView)findViewById(R.id.expertscommentsListView);
        String[] colummnames = { "news_title","imagepath","descripton"}; 
        cursor = dh.fetchtitle(category_id);
        int []id=  { R.id.titleTextView,R.id.descriptionTextView,R.id.imagview2};
        SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,  R.layout.new_list, cursor , colummnames,id);
        list.setAdapter(adapter);
        adapter.notifyDataSetChanged();
        list.setOnItemClickListener(this);
    }

我已经显示数据库文件apply select * from table name我已经显示了数据IMage路径列及其值但是我无法显示请帮助我做错了我已经采取了r.imageview

Answer 1

我怀疑SimpleCursorAdapter可以在您的布局中找到ImageView，然后将字节数组解码为Bitmap并为ImageView设置图像。您必须覆盖getView()适配器，并在getView()中自行完成。

示例：

数据类：

public class NewsItem{
  public final String newsTitle;
  public final byte[] imageData;
  public final String description;

  public NewsItem (String title, byte[] data, String desc){
    this.newsTitle = title;
    this.imageData = data;
    this.description = desc;
  }
}

适配器：

ArrayAdapter<NewsItem> adapter = new ArrayAdapter<NewsItem>(this){
  @Override
  public View getView(int position, View convertView, View parent){

    if(convertView == null){
       convertView = //--inflate list item layout
    }

    NewsItem item = getItem(position);

    ImageView i = convertView.findViewById(R.id.myImageView);
    Bitmap b = BitmapFactory.decodeByteArray(item.imageData,0,item.imageData.length);
    i.setDrawable(new BitmapDrawable(b));

    //--other stuff

    return convertView;
  }
};

填写适配器：

Cursor c = dh.fetchtitle(category_id);
while (c.moveToNext()){
  adapter.add(new NewsItem(c.getString(0),c.getBlob(1),c.getString(2)));  
}

Answer 2

通过您已完成的方式定义适配器将无法工作，除非您为图像提供资源ID（如R.id.imagename）。

我认为您需要通过路径从互联网上获取图像。最好创建一个扩展BaseAdapter的自定义适配器类。在getView()内，你可以拥有下载图像的逻辑（通过AsynTask）然后显示它。

如何从sqlite数据库中显示（检索）图像

2 个答案: