C# 在SQLite数据库中存储图像

建表语句

CREATE TABLE [ImageStore]([ImageStore_Id] INTEGER  NOT NULL PRIMARY KEY AUTOINCREMENT,[ImageFile] NVARCHAR(20)  NULL,[ImageBlob] BLOB  NULL
);

加载图像

privateImageLoadImage(){//Create an instance of the Image Class/Object//so that we can store the information about the picture an send it back for//processing into the database.Image image =null;//Ask user to select ImageOpenFileDialog dlg =newOpenFileDialog();
    dlg.InitialDirectory=@"C:\\";
    dlg.Title="Select Image File";//dlg.Filter = "Tag Image File Format (*.tiff)|*.tiff";//dlg.Filter += "|Graphics Interchange Format (*.gif)|*.gif";//dlg.Filter += "|Portable Network Graphic Format (*.png)|*.png";//dlg.Filter += "|Joint Photographic Experts Group Format (*.jpg)|*.jpg";//dlg.Filter += "|Joint Photographic Experts Group Format (*.jpeg)|*.jpeg";//dlg.Filter += "|Nikon Electronic Format (*.nef)|*.nef";//dlg.Filter += "|All files (*.*)|*.*";
    dlg.Filter="Image Files  (*.jpg ; *.jpeg ; *.png ; *.gif ; *.tiff ; *.nef)
                |*.jpg;*.jpeg;*.png;*.gif;*.tiff;*.nef";
    dlg.ShowDialog();this.FileLocation= dlg.FileName;if(fileLocation ==null|| fileLocation ==string.Empty)return image;if(FileLocation!=string.Empty&& fileLocation !=null){Cursor.Current=Cursors.WaitCursor;//Get file information and calculate the filesizeFileInfo info =newFileInfo(FileLocation);long fileSize = info.Length;//reasign the filesize to calculated filesize
    maxImageSize =(Int32)fileSize;if(File.Exists(FileLocation)){//Retreave image from file and binary it to Object imageusing(FileStream stream =File.Open(FileLocation,FileMode.Open)){BinaryReader br =newBinaryReader(stream);byte[] data = br.ReadBytes(maxImageSize);
        image =newImage(dlg.SafeFileName, data, fileSize);}}Cursor.Current=Cursors.Default;}return image;}

存储图像

publicInt32InsertImage(){DataRow dataRow =null;
    isSucces =false;Image image =LoadImage();//if no file was selected and no image was created return 0if(image ==null)return0;if(image !=null){// Determin the ConnectionStringstring connectionString = dBFunctions.ConnectionStringSQLite;// Determin the DataAdapter = CommandText + Connectionstring commandText ="SELECT * FROM ImageStore WHERE 1=0";// Make a new object
    helper =new dBHelper(connectionString);{// Load Dataif(helper.Load(commandText,"image_id")==true){// Add a row and determin the row
        helper.DataSet.Tables[0].Rows.Add(
                   helper.DataSet.Tables[0].NewRow());
        dataRow = helper.DataSet.Tables[0].Rows[0];// Enter the given values
        dataRow["imageFileName"]= image.FileName;
        dataRow["imageBlob"]= image.ImageData;
        dataRow["imageFileSizeBytes"]= image.FileSize;try{// Save -> determin succesif(helper.Save()==true){
            isSucces =true;}else{
            isSucces =false;MessageBox.Show("Error during Insertion");}}catch(Exception ex){// Show the Exception --> Dubbel Id/Name ?MessageBox.Show(ex.Message);}}//END IF}}//return the new image_idreturnConvert.ToInt32(dataRow[0].ToString());}

另存为图像文件

publicvoidSaveAsImage(Int32 imageID){//set variablesDataRow dataRow =null;Image image =null;
    isSucces =false;// Displays a SaveFileDialog so the user can save the ImageSaveFileDialog dlg =newSaveFileDialog();
    dlg.InitialDirectory=@"C:\\";
    dlg.Title="Save Image File";//1
    dlg.Filter="Tag Image File Format (*.tiff)|*.tiff";//2
    dlg.Filter+="|Graphics Interchange Format (*.gif)|*.gif";//3
    dlg.Filter+="|Portable Network Graphic Format (*.png)|*.png";//4
    dlg.Filter+="|Joint Photographic Experts Group Format (*.jpg)|*.jpg";//5
    dlg.Filter+="|Joint Photographic Experts Group Format (*.jpeg)|*.jpeg";//6
    dlg.Filter+="|Bitmap Image File Format (*.bmp)|*.bmp";//7
    dlg.Filter+="|Nikon Electronic Format (*.nef)|*.nef";
    dlg.ShowDialog();// If the file name is not an empty string open it for saving.if(dlg.FileName!=""){Cursor.Current=Cursors.WaitCursor;//making shore only one of the 7 is being used.//if not added the default extention to the filenamestring defaultExt =".png";int pos =-1;string[] ext =newstring[7]{".tiff",".gif",".png",".jpg",".jpeg",".bmp",".nef"};string extFound =string.Empty;string filename = dlg.FileName.Trim();for(int i =0; i < ext.Length; i++){
        pos = filename.IndexOf(ext[i], pos +1);if(pos >-1){
        extFound = ext[i];break;}}if(extFound ==string.Empty) filename = filename + defaultExt;// Determin the ConnectionStringstring connectionString = dBFunctions.ConnectionStringSQLite;// Determin the DataAdapter = CommandText + Connectionstring commandText ="SELECT * FROM ImageStore WHERE image_id="+ imageID;// Make a new object
    helper =new dBHelper(connectionString);// Load the dataif(helper.Load(commandText,"")==true){// Show the data in the datagridview
        dataRow = helper.DataSet.Tables[0].Rows[0];
        image =newImage((string)dataRow["imageFileName"],(byte[])dataRow["imageBlob"],(long)dataRow["imageFileSizeBytes"]);// Saves the Image via a FileStream created by the OpenFile method.using(FileStream stream =newFileStream(filename,FileMode.Create)){BinaryWriter bw =newBinaryWriter(stream);
        bw.Write(image.ImageData);
        isSucces =true;}}Cursor.Current=Cursors.Default;}if(isSucces){MessageBox.Show("Save succesfull");}else{MessageBox.Show("Save failed");}}

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