Question

数据库初始化：

private final static String DBNAME = "Auction";
private final static int DBVERSION = 2;

SQLiteDatabase mDB5;

public final static String TBL_AUCTION = "Auction";
public final static String COL_AUCTION_ID = BaseColumns._ID;
public final static String COL_AUCTION_NAME = "name";
public final static String COL_AUCTION_DESCRIPTION = "description";
public final static String COL_AUCTION_PRICE = "price";
public final static String COL_AUCTION_DURATION = "duration";
public final static String COL_AUCTION_IMAGE = "image";


private String crt_tbl_auction = "CREATE TABLE IF NOT EXISTS " + TBL_AUCTION + "(" +
        COL_AUCTION_ID + " INTEGER PRIMARY KEY, " +
        COL_AUCTION_NAME + " TEXT, " +
        COL_AUCTION_DESCRIPTION + " TEXT, " +
        COL_AUCTION_PRICE + " TEXT, " +
        COL_AUCTION_DURATION + " TEXT, " +
        COL_AUCTION_IMAGE + " BLOB " +
        ")";

public DatabaseHelper5(Context context) {
    super(context, DBNAME, null, DBVERSION);
    mDB5 = this.getWritableDatabase();
}

insertData：

public long insertData(String name, String description, String price, String duration,byte[] image) {
    ContentValues cv = new ContentValues();
    cv.put(COL_AUCTION_NAME, name);
    cv.put(COL_AUCTION_DESCRIPTION, description);
    cv.put(COL_AUCTION_PRICE, price);
    cv.put(COL_AUCTION_DURATION, duration);
    cv.put(COL_AUCTION_IMAGE,String.valueOf(image));

    return mDB5.insert(TBL_AUCTION, null, cv);
}

getData：

public Cursor getDataV2() {

        SQLiteDatabase db = this.getReadableDatabase();
        String[] projection = {
                COL_AUCTION_ID,
                COL_AUCTION_IMAGE,
                COL_AUCTION_NAME
        };

    return db.query(
                TBL_AUCTION,   // The table to query
                projection,             // The array of columns to return (pass null to get all)
                null, null, null, null, BaseColumns._ID + " DESC"
        );

}

MainActivity：

gridView = (GridView)findViewById(R.id.gridView);
    list = new ArrayList<>();
    adapter = new AuctionAdapter(this,R.layout.auction_items,list);
    gridView.setAdapter(adapter);
    myDB5 = new DatabaseHelper5(this);


    wholegrid = myDB5.getDataV2();
    if (sma == null) {
        sma = new SimpleCursorAdapter(
                this,
                android.R.layout.simple_list_item_2,wholegrid,
                new String[]{DatabaseHelper5.COL_AUCTION_IMAGE, DatabaseHelper5.COL_AUCTION_NAME},
                new int[]{android.R.id.text1,android.R.id.text2},
                0
        );
        gridView.setAdapter(sma);
    }
    adapter.notifyDataSetChanged();

}

我无法将字符串图像转换回图像并显示在GridView上。我将其转换为字符串的原因是，如果没有String.valueOf，我的应用程序将崩溃，并显示错误消息，提示它无法将BLOB转换为字符串。我有什么办法可以最少地编辑代码来解决此问题？我只希望它能够检索图像数据并将图像显示到GridView，仅此而已。欢迎任何方法。谢谢！

将SQLite中的字符串图像转换回图像以显示在网格视图中

0 个答案: