我如何将 Sqlite 数据库中的图像保存为 blob？

Question

这是我用来在 database.cs 中将图片保存为 base64String TEXT 的代码。

public void CreateDatabase(string sqldb_name)
        {
            try
            {
                sqldb_message = "";
                string sqldb_location = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal);
                string sqldb_path = Path.Combine(sqldb_location, sqldb_name);
                bool sqldb_exists = File.Exists(sqldb_path);
                if(!sqldb_exists)
                {

                    //Adding new fields
                    //For adding new fields we have to define the field on the "create" query, in this case, we're adding "BirthDay" field which is VARCHAR
                    sqldb = SQLiteDatabase.OpenOrCreateDatabase(sqldb_path,null);
                    sqldb_query = "CREATE TABLE IF NOT EXISTS MyTable (_id INTEGER PRIMARY KEY AUTOINCREMENT, Art TEXT, Album VARCHAR, Artist VARCHAR, Country VARCHAR, Year INT, Genre VARCHAR, Style VARCHAR, Format VARCHAR);";

                    sqldb.ExecSQL(sqldb_query);
                    sqldb_message = "Database: " + sqldb_name + " created";
                }
                else
                {
                    sqldb = SQLiteDatabase.OpenDatabase(sqldb_path, null, DatabaseOpenFlags.OpenReadwrite);
                    sqldb_message = "Database: " + sqldb_name + " opened";
                }
                sqldb_available=true;
            }
            catch(SQLiteException ex) 
            {
                sqldb_message = ex.Message;
            }
        }
        //Adds a new record with the given parameters

        //Adding new fields
        //We have to modify the CRUD (Create, Read, Update and Delete) operations by adding the new "BirthDay" field, in this case, we're adding the new string parameter "sBirthDay"
        public void AddRecord(string @IMG, string sAlbum, string sArtist, string sCountry, int iYear, string sGenre, string sStyle, string sFormat)
        {
            try
            {
                //Adding new fields
                //We have to modify the CRUD (Create, Read, Update and Delete) operations by adding the new "BirthDay" field to the query and assign the value "sBirthDay"
                sqldb_query = "INSERT INTO MyTable (Art, Album, Artist, Country, Year, Genre, Style, Format) VALUES ('" + @IMG + "','" + sAlbum + "','" + sArtist + "','" + sCountry + "','" + iYear + "','" + sGenre + "','" + sStyle + "','" + sFormat + "');";

                sqldb.ExecSQL(sqldb_query);
                sqldb_message = "Record saved";
            }
            catch(SQLiteException ex) 
            {
                sqldb_message = ex.Message;
            }
        }

我应该对代码进行哪些更改才能将图像保存为数据库中的 blob？

Answer 1

有两种保存图片的方法

1.You 可以使用位图将其保存在文件中，然后获取图像路径并将其作为字符串保存在 Db 中

2.Convert 将其转换为字节数组并保存为 Blob

ByteArrayOutputStream stream = new ByteArrayOutputStream();
bmp.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();

Answer 2

SQLite 旨在包含大约 400KB 的数据。将图像存储在 SQLite Db 中不会很好。上面写的图片路径方法比较好

如果适合您的需要，您最好使用 Picasso、Universal Image Loader 等图像加载库。这样你就可以只保留图像url。图像由库缓存。

我如何将 Sqlite 数据库中的图像保存为 blob？

How i can save an Image in Sqlite database as blob?

sqlite

android

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