ios - 图像是由 UIImagePickerControllerSourceTypeCamera 拍摄的如何将其保存在 ios 的数据库中

Question

.m 编码

-(IBAction) getPhoto:(id) sender {
    picker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;

} else {
    if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
        UIAlertView *noCameraAlert = [[UIAlertView alloc] initWithTitle:@"Error"
                                                                message:@"You don't have a camera for this device" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];

        //shows above alert if there's no camera
        [noCameraAlert show];
    }else{
        picker.sourceType    = UIImagePickerControllerSourceTypeCamera;
        picker.allowsEditing = YES;
        picker.delegate      = self;
    }
}
[self presentViewController:picker animated:YES completion:nil];
}

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
     UIImage *img     = [info objectForKey:UIImagePickerControllerOriginalImage];
img              = [info valueForKey:UIImagePickerControllerEditedImage];
self.imageView.image  = img;
imagData         = UIImagePNGRepresentation(img);
[picker dismissViewControllerAnimated:YES completion:nil];
}

现在图像已放在 ImageView 中，我如何将图像保存在数据库中

我已经有了数据库来插入数据插入:

NSMutableArray *listItemsarr = [[NSMutableArray alloc] init];
        if([listItemsarr count]==0){
            NSString *insertQry=@"INSERT INTO selection_tbl (expenses_value,category,date,payment,description) VALUES(?,?,?,?,?)";
            sqlite3_stmt *stmt=[DB OpenSQL:[insertQry UTF8String]];
            if(stmt !=nil)
            {
                sqlite3_bind_text(stmt,1, [dataTextfield.text UTF8String], -1, SQLITE_TRANSIENT);
                sqlite3_bind_text(stmt,2, [[selectionarray objectAtIndex:0]  UTF8String], -1, SQLITE_TRANSIENT);
                sqlite3_bind_text(stmt,3, [[selectionarray objectAtIndex:1]  UTF8String], -1, SQLITE_TRANSIENT);
                sqlite3_bind_text(stmt,4, [[selectionarray objectAtIndex:2]  UTF8String], -1, SQLITE_TRANSIENT);
                sqlite3_bind_text(stmt,5, [[selectionarray objectAtIndex:3]  UTF8String], -1, SQLITE_TRANSIENT);


                sqlite3_step(stmt);
            }
            sqlite3_finalize(stmt);
            [DB CloseSQL];

以下代码用于更新数据库值更新:

NSInteger proeditid = [primarykeyID integerValue];
        NSString *updateQry=@"update selection_tbl set expenses_value=?,category=?,date=?,payment=?,description=? where expenses_id=?";
        sqlite3_stmt *stmt=[DB OpenSQL:[updateQry UTF8String]];
        if(stmt !=nil)
        {
            sqlite3_bind_text(stmt,1, [dataTextfield.text UTF8String], -1, SQLITE_TRANSIENT);
            sqlite3_bind_text(stmt,2, [[selectionarray objectAtIndex:0] UTF8String], -1, SQLITE_TRANSIENT);
            sqlite3_bind_text(stmt,3, [[selectionarray objectAtIndex:1] UTF8String], -1, SQLITE_TRANSIENT);
            sqlite3_bind_text(stmt,4, [[selectionarray objectAtIndex:2] UTF8String], -1, SQLITE_TRANSIENT);
            sqlite3_bind_text(stmt,5, [[selectionarray objectAtIndex:3] UTF8String], -1, SQLITE_TRANSIENT);


            sqlite3_bind_int(stmt,6, (int)proeditid);
            sqlite3_step(stmt);
        }
        sqlite3_finalize(stmt);
        [DB CloseSQL];

Answer 1

有两个问题:

1. 如何获取 NSData图像的表示？

   • 简单的方法是使用 UIImagePNGRepresentation的 UIImage .

   • 更好的方法是使用 getBytes检索原始 Assets 。参见 https://stackoverflow.com/a/25251943/1271826 .

2. 如何保存 NSData SQLite 数据库中的表示？

   保存这个NSData在您的数据库中，然后使用 sqlite3_bind_blob .该过程与 sqlite3_bind_xxx 非常相似您之前与我们分享的功能。使用 bytes NSData的方法|访问指向缓冲区的 C 样式指针，并将其传递给 sqlite3_bind_blob .

请注意，众所周知，在 SQLite 数据库中保存全尺寸图像效率低下。 SQLite 不能很好地处理大的 blob。通常人们更愿意保存 NSData到设备永久存储上的文档文件夹中的一个文件中，然后只保存 path数据库中的那个文件。