Question

我在DBBrowser中创建了一个图像文件，现在我想在其中保存图像然后检索它。这是我的代码 -

-(void)saveListImages {
    if(sqlite3_open([[[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:image] UTF8String], &database) == SQLITE_OK) {
        NSString *query = [NSString stringWithFormat:@"SELECT * FROM image where id=%i"];
        //NSLog(@";query = \n%@";, query);
        sqlite3_stmt *statement;
        if (sqlite3_prepare_v2(database, [query UTF8String], -1, &statement, nil) == SQLITE_OK) {
            while (sqlite3_step(statement) == SQLITE_ROW) {
                if (sqlite3_column_blob(statement, 0) != NULL) {
                    //NSLog(@";read a non NULL image");
                    NSData *data = [[NSData alloc] initWithBytes:sqlite3_column_blob(statement, 0) length:sqlite3_column_bytes(statement, 0)];
                    imageView.image = [UIImage imageWithData:data];

                }
                else {
                    NSLog(@";read a NULL image");
                }
            }
            sqlite3_finalize(statement);
        }
    }
    sqlite3_close(database);
}

Answer 1

你不能将图像存储在数据库中，首先将图像转换为NSString，并在数据库图像列中将类型设置为blob

- (NSString *)encodeToBase64String:(UIImage *)image {
return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64EncodingEndLineWithCarriageReturn];
}

- (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData {
NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters];
return [UIImage imageWithData:data];
}

将图像转换为Base64String

NSString *imageString = [self encodeToBase64String:image];

  // Store base64String into Database

需要时在imageView中显示图像，只需从数据库中获取图像字符串而不是转换为图像

 imageView.image=[self decodeBase64ToImage:imageString];

保存和检索数据库中的图像

1 个答案: