如何将图像存储在 iPhone 的 sqlite 数据库中？ [关闭]

Posted 2023-05-07

【中文标题】如何将图像存储在 iPhone 的 sqlite 数据库中？ [关闭]

【英文标题】：How to store image in sqlite database in iphone? [closed]

【发布时间】：2013-03-07 05:06:20

【问题描述】：

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"image.sqlite"];


    if (sqlite3_open_v2([path UTF8String], &database, SQLITE_OPEN_READWRITE, NULL) == SQLITE_OK)
    


        if(selectStmt == nil)
        
            const char *sql = "insert into imagetb(imagename,image) Values(?,?)";
            if(sqlite3_prepare_v2(database, sql, -1, &selectStmt, NULL) != SQLITE_OK)
                //              NSAssert1(0, @"Error while creating add statement. '%s'", sqlite3_errmsg(database));
                NSLog(@"%s",sqlite3_errmsg(database));
        



        sqlite3_bind_text(selectStmt, 1, [@"test.png" UTF8String], -1, SQLITE_TRANSIENT);

         sqlite3_bind_blob(selectStmt, 2, [data1 bytes], [data1 length], SQLITE_TRANSIENT);

        if(SQLITE_DONE != sqlite3_step(selectStmt))
            NSLog(@"get: %s",sqlite3_errmsg(database));
        else
            NSLog(@"scan data added");


    

    //showimage
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];


    if (sqlite3_open([path UTF8String], &database) == SQLITE_OK)
    
        const char *sql = "select * from imagetb";// LIMIT 0,100 ";// where status = 1 ";
        sqlite3_stmt *selectstatment;

        if (sqlite3_prepare_v2(database, sql, -1, &selectstatment, NULL) == SQLITE_OK)
        
            while (sqlite3_step(selectstatment) == SQLITE_ROW)
            

                NSString *getorgstrid = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstatment, 0)];
                NSLog(@"id->%@",getorgstrid);

                [getid addObject:getorgstrid];

                NSString *getorgstrname = [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstatment, 1)];
                NSLog(@"name->%@",getorgstrname);
                [getname addObject:getorgstrname];


                NSData *getorgstrimage = [[NSData alloc] initWithBytes:sqlite3_column_blob(selectstatment,2)length:sqlite3_column_bytes(selectstatment, 2)];

                [getimage addObject:getorgstrimage];

            
        
        sqlite3_finalize(selectstatment);

    
    //[tblorgland reloadData];

    UIImage *image1 = [UIImage imageWithData:[getimage lastObject]];

    NSLog(@"image%@",image1);

    [getImageview setImage:image1];
    [pool release];


==============================================================================

- (NSString *) getDBPath

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
    NSString *documentsDir = [paths objectAtIndex:0];

    return [documentsDir stringByAppendingPathComponent:@"image.sqlite"];


- (void)viewDidLoad

    [super viewDidLoad];

    getid=[[NSMutableArray alloc]init];
    getname=[[NSMutableArray alloc]init];
    getimage=[[NSMutableArray alloc]init];

    [self downloadimage];
    [self makeDBCopyAsNeeded];

-(void)downloadimage

    NSLog(@"Downloading...");

    UIImage *image = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://0.tqn.com/d/graphicssoft/1/7/g/A/5/psptubezdotcom_003.png"]]];

    NSLog(@"%f,%f",image.size.width,image.size.height);


    NSString *docDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];


    NSLog(@"%@",docDir);

    NSLog(@"saving png");
    pngFilePath = [NSString stringWithFormat:@"%@/test.png",docDir];
    data1 = [NSData dataWithData:UIImagePNGRepresentation(image)];

    img=[[UIImage alloc]initWithData:data1];



    [data1 writeToFile:pngFilePath atomically:YES];


    NSLog(@"saving jpeg");
    NSString *jpegFilePath = [NSString stringWithFormat:@"%@/test.jpeg",docDir];

    NSLog(@"jpegFilePath:%@",jpegFilePath);
    data2 = [NSData dataWithData:UIImageJPEGRepresentation(image, 1.0f)];

    [data2 writeToFile:jpegFilePath atomically:YES];

    NSLog(@"saving image done");

    [image release];



- (void) makeDBCopyAsNeeded

    BOOL success;
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSError *error;
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"image.sqlite"];
    success = [fileManager fileExistsAtPath:writableDBPath];

    NSString *dbPath = [self getDBPath];
    NSLog(@"%@",dbPath);

    if (success)
    
        NSLog(@"Database Success Created");
        return;
    
    NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"image.sqlite"];
    success = [fileManager copyItemAtPath:defaultDBPath toPath:writableDBPath error:&error];
    if (!success)
    
        NSLog(@"Database:->%s",sqlite3_errmsg(database));
    

【问题讨论】：

您可以将图像的路径存储到数据库中，而不是存储整个图像

看看 SO 问题 :***.com/questions/5039343/… 。希望这会对你有所帮助。

将图像写入文件系统要好得多。您可以引用数据库中的文件名。

S 最好将图像存储在 Document 目录中，并使用一些唯一的 id 作为图像名称，以便更好地使用..

我会存储图片的地址。当需要将图片加载到 UIImageView 时，使用 imageWithContentsOfFile 将图片加载到 UIImageView

【参考方案1】：

不建议将图片数据存储在sqlite中。但是如果你想存储图像数据然后使用这个链接

Save image data to sqlite database in iphone

希望对你有帮助..

【参考方案2】：

你最好使用缓存来存储你的图片，并使用数据库来存储他们的名字或一些唯一的ID

【讨论】：

可以清除缓存目录。那不是存储无法替换的数据的好地方。

而不是存储图像数据，您应该使用将图像名称存储在数据库中。因此它将减少从数据库存储和获取的时间

【参考方案3】：

只需在 -(void)imagePickerController:(UIImagePickerController *)picker 中编写以下代码 didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo: 如果你从画廊或相机中获取图像，否则跳过 if (imageData != nil) 下的代码，只需使用下面的代码将图像保存在 sqlite 中

NSData * imageData = UIImageJPEGRepresentation(image, 0.8);
    NSLog(@"Image data length== %d",imageData.length);

if (imageData != nil)
    
        UIImage *resizedImg = [self scaleImage:[UIImage imageWithData:imageData] toSize:CGSizeMake(150.0f,150.0f)];

        NSData * imageData = UIImageJPEGRepresentation(resizedImg, 0.2);
        NSLog(@"*** Image data length after compression== %d",imageData.length);

        NSString *nameofimg=[NSString stringWithFormat:@"%@",resizedImg];

        NSString *substring=[nameofimg substringFromIndex:12];
        NSString *new=[substring substringToIndex:7];// Get image name

        NSArray *path=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

        NSString *documentdirectory=[path objectAtIndex:0];

        NSString *newFilePath = [NSString stringWithFormat:[documentdirectory stringByAppendingPathComponent: @"/%@.png"],new];

        [imageData writeToFile:newFilePath atomically:YES];

        imgpath=[[NSString alloc]initWithString:newFilePath];
        NSLog(@"doc img in img method === %@",imgpath);
    


     databasepath=[app getDBPath]; // i have this method in delegate
        if (sqlite3_open([databasepath UTF8String], &dbAssessor) == SQLITE_OK)
        
            NSString *selectSql = [NSString stringWithFormat:@"insert into imagetb(imagename,image) VALUES(\"%@\",\"%@\") ;",yourImgName,imgpath];

            NSLog(@"Query : %@",selectSql);

            const char *sqlStatement = [selectSql UTF8String];
            sqlite3_stmt *query_stmt;
            sqlite3_prepare(dbAssessor, sqlStatement, -1, &query_stmt, NULL);

            if(sqlite3_step(query_stmt)== SQLITE_DONE)
            
                NSLog(@"home image updated. :)");
                app.houseImage=imgpath;
            
            else
            
                UIAlertView *alert = [[UIAlertView alloc]
                                      initWithTitle:@"Sorry" message:@"Failed To Save Home Image." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
                [alert show];
                [alert release];
            
            sqlite3_finalize(query_stmt);
        
        sqlite3_close(dbAssessor);

【讨论】：

这个问题与从图像选择器中选择图像有什么关系？