I want to add some rows to a database using Linq to SQL, but I want to make a "custom check" before adding the rows to know if I must add, replace or ignore the incomming rows. I'd like to keep the trafic between the client and the DB server as low as possible and minimize the number of queries. To do this, I want to fetch as little information as required for the validation, and
我想使用Linq to SQL将一些行添加到数据库，但是我想在添加行之前进行“自定义检查”，以了解是否必须添加，替换或忽略包含的行。 我想保持客户端和数据库服务器之间的交通尽可能低，并尽量减少查询次数。 为此，我想获取验证所需的尽可能少的信息，并且只在过程开始时获取一次。 我正在考虑这样做，但很明显，它不起作用。 任何人有想法？ Dictionary<int, DateTime> existingItems = (from ObjType ot in Table
I'm trying to perform a simple LINQ query on the Columns property of a DataTable: from c in myDataTable.Columns.AsQueryable() select c.ColumnName However, what I get is this: Could not find an implementation of the query pattern for source type 'System.Linq.IQueryable'. 'Select' not found. Consider explicitly specifying the type of the range variable 'c'. H
我试图在DataTable的Columns属性上执行一个简单的LINQ查询： from c in myDataTable.Columns.AsQueryable() select c.ColumnName 但是，我得到的是这样的： 找不到源类型为“System.Linq.IQueryable”的查询模式的实现。 '选择'未找到。 考虑明确指定范围变量'c'的类型。 我怎样才能让DataColumnCollection和LINQ一起玩呢？ 怎么样： var x = from c in dt.Columns.Cast<DataColumn>()
Is there any way to synchronously consume raw byte messages from RabbitMQ using EasyNetQ? I need to guarantee in-order processing and acking of messages coming from a system that does not publish in EasyNetQ format. I know the consumer runs on a single thread, but the IAdvancedBus interface only offers one method to consume raw messages: IDisposable Consume(IQueue queue, Func<byte[], Messa
是否有任何方法可以同步使用EasyNetQ从RabbitMQ消耗原始字节消息？ 我需要保证按顺序处理和确认来自未以EasyNetQ格式发布的系统的消息。 我知道消费者在单个线程上运行，但IAdvancedBus接口只提供一种消耗原始消息的方法： IDisposable Consume(IQueue queue, Func<byte[], MessageProperties, MessageReceivedInfo, Task> onMessage); Task返回类型意味着消费者正在异步运行回调，因此可能会按顺序处理消息。 如果
I am trying to get the keyboard delay effect in a menu while the keyboard is held down. Currently it works, but not after changing directions. For example I could press and hold right and the cursor world move over right, then pause, then continually travel right (as expected). I could release and press right or press and hold right and it would work. Pressing and holding left doesn't wor
我试图在按住键盘的同时在菜单中获得键盘延迟效果。 目前它可以工作，但不会在改变方向之后。 例如，我可以按住右键，光标世界右移，然后暂停，然后继续向右移动（如预期的那样）。 我可以释放并按右键或按住右键，它会工作。 按住左键不起作用，光标立即全速前进。 奇怪的是，如果我释放并保持左后，它的作品。 在此之后按住右键会使光标立即全速移动，并且像上面这样只会影响第一次。 这里是我正在处理的函数：（许多
I need to find the best way to record an audio stream. I have already built the low level code in C++ and interfaced parts of it to C#. So i have a C++ callback that gives me an array of array of floats - the audio signal. At the moment, my C++ lib is recording the data straight to the file in the wav format and it just notify my C# app when it ends recording. But, I would like to have more
我需要找到录制音频流的最佳方式。 我已经在C ++中构建了低级代码，并将其部分接口到C＃中。 所以我有一个C ++回调，它给了我一个浮点数组的数组 - 音频信号。 目前，我的C ++ lib以wav格式直接记录数据，并在结束记录时通知我的C＃应用程序。 但是，我希望在UI方面有更多的交互性，比如“无限”进度条，记录的数据量，取消按钮等等，并且因为最糟糕的时候会是一分钟，所以最好将它保存在内存中。 我对.NET和C＃内存管理
I know the basics of C and I'm looking into SDL. What I need at this point are some tutorials, documentation or perhaps a book about using the SDL libraries in C, especially about graphics. The problem is that every online resource that I have found deals with C++, where I am looking for resources in C. I have looked at gpwiki.org, which had an entire section on C but mingw won't com
我知道C的基本知识，我正在研究SDL。 我现在需要的是一些教程，文档或者一本关于在C中使用SDL库的书，尤其是关于图形的书。 问题是我找到的每一个在线资源都与C ++有关，我在C中寻找资源。 我查看了gpwiki.org，它有关于C的完整部分，但mingw不会编译它，因为一些包含的是C ++库（我只安装了C编译器）。 其他来源，比如sol.gfxile.net/gp/，说他们是一个C教程，但是“使用C ++来实现其方便的变量放置规则”。 SDL网站上的大
I want to separate low, mid and high frequencies from .wav file. for that i have used FFT to convert data from time domain to frequency domain. code for reading file and applying Fast Fourier Transform with help of NAudio is like OpenFileDialog file = new OpenFileDialog(); file.ShowDialog(); WaveFileReader reader = new WaveFileReader(file.FileName); int samepleRate = r
我想从.wav文件中分离出低频，中频和高频。 因为我已经使用FFT将数据从时域转换到频域。 在NAudio的帮助下读取文件和应用快速傅立叶变换的代码就像 OpenFileDialog file = new OpenFileDialog(); file.ShowDialog(); WaveFileReader reader = new WaveFileReader(file.FileName); int samepleRate = reader.WaveFormat.SampleRate; double ts = 1.0 / samepleRate; int _fftLength =
I have a list of amplitude frequency response points. The amplitudes are given in decibels. The task is to export this AFR list to a set of coefficients for some hardware DSP device. I know the file format for this device. The specification for the device says that it needs 12288 coefficients and the DSP has 2 FIR filter blocks (6144 taps each). The idea is that after loading those coeffici
我有一个幅度频率响应点列表。 振幅以分贝为单位给出。 其任务是将此AFR列表导出为某些硬件DSP设备的一组系数。 我知道这个设备的文件格式。 该器件的规格说明它需要12288个系数，DSP有2个FIR滤波器模块（每个6144个抽头）。 这个想法是，在加载这些系数后，这个设备应该作为一个均衡器，根据初始的频率点列表对信号进行变换。 我发现FIR滤波器的系数可以通过对所需频率响应进行傅立叶逆变换并使用一些窗函数（最好不是
EF 6.1.3 I have an entity called DietPlan. It has a Many to Many relationship with Meals. There is a use case where a Diet Plan exists with a relational record to a meal already, and we want to add a new meal to that plan. I do this by DietPlan.Meals.Clear() then I call saveChanges (see code below), then I add the records that should be there, allowing for a delete and add in one shot. Wha
EF 6.1.3 我有一个名为DietPlan的实体。 它与餐饮有着多对多的关系。 有一个用餐案例，饮食计划已经存在并且与膳食有关系记录，我们希望为该计划添加一顿新餐。 我通过DietPlan.Meals.Clear（）来做到这一点，然后我调用saveChanges（请参阅下面的代码），然后添加应该在那里的记录，从而允许删除并添加一次。 我觉得奇怪的是，饮食计划中的膳食仍然“附加”在记忆中，因为如果我尝试打电话给已经存在的膳食附加，我得到这
I am currently working on a project using the latest version of Entity Framework and I have come across an issue which I can not seem to solve. When it comes to updating existing objects, I can fairly easily update the object properties ok, until it comes to a property which is a reference to another class. In the below example I have a class called Foo, which stores various properties, with
我目前正在使用最新版本的Entity Framework开发一个项目，并且遇到了一个我似乎无法解决的问题。 当涉及到更新现有对象时，我可以很容易地更新对象属性，直到涉及到对另一个类的引用的属性。 在下面的例子中，我有一个名为Foo的类，它存储各种属性，其中2个是其他类的实例 public class Foo { public int Id {get; set;} public string Name {get; set;} public SubFoo SubFoo {get; set} public Anothe