Edi Wang

All Posts 295


Merge Data for N-N Relationship Tables in T-SQL

最近在整理博客的数据,需要做一个操作就是合并文章的分类。我的博客中文章和分类是多对多的关系。即一篇文章可以属于多个分类,一个分类可以包含多篇文章。这是一个很典型的多对多关系,我用的是一个多对多的表,做联合主键关联这些数据。 就像这样: 我需要做的是把“DotNetBeginner”这个分类的文章移到“CSharpAndDotNet”分类里去。但是因为原先在“DotNetBeginner”里的文章有些也是属于“CSharpAndDotNet”的,所以直接Update关联表的话,会产生重复的联合主键,就会爆。 直观一点看,写个SQL语句查询出原分类(DotNetBeginner)和目标分类(CSharpAndDotNet)中的数据: DECLARE @SourceCatId AS UNIQUEIDENTIFIER, @TargetCatId A...

SQL SQL Server T SQL

Get system font and characters in Windows 10 UWP

There used to be a {x:Static Fonts.SystemFontFamilies} in WPF that can bind to system font list very easy. However, this is gong in UWP! How stupid it is! These days I wrote a character map UWP application, that would use system fonts, so I did some research. In order to get system font in UWP, we must use DirectX. Install these 3 NuGet pacakges into your project: "SharpDX": "3.0.1", "Sharp...

Windows 10 UWP DirectX

How to Remove ListView Default Selection in Windows 10 UWP

A lot of people including me has encounter a problem where on UWP apps, if a ListView control is being data binded, it will get a default selected item like this: It not only will display as selected item, it also fires SelectionChanged event. However, if we want to make ListView clickable, a popular way is to write the SelectionChanged event handler like this: private void StationsList_OnSele...

Windows 10 UWP

How to make a modal progress dialog in Windows 10 UWP

Windows 10 Mobile上的文件管理器有这样一个进度指示器,它是一个模态框,不带任何按钮,只有进度条和文本: 今天我琢磨了很久,绕了一些弯路,发现其实要做一个这样的模态进度指示器很简单。只要用ContentDialog就行。 平时我们用ContentDialog有些思维定势,就觉得这个对话框一定要提供按钮给用户操作。其实它是可以不设置任何按钮的,这样就有了初步的雏形: XAML C# private async void BtnSitAndRelax_OnClick(object sender, RoutedEventArgs e) { // show progress await ModalProgressDig...

Windows 10 UWP

UWP App for the Raspberry Pi Azure Surveillance Camera

I wrote a post about Raspberry Pi Surveillance Camera with Linux and Azure, it was using an ASP.NET website for displaying the photos. I made an UWP client App these days, you can download from here https://www.microsoft.com/store/apps/9nblgggzfnv0 (Because WP is already finished, so I don't provide Windows 10 Mobile package) It doesn't allow upload photos, because the photos should all come f...

MVVM PIN Microsoft Passport Binding

Read AppSettings in ASP.NET Core 2.0

10/15/2017: Updated for ASP.NET 2.0 Today, I was rewriting an old ASP.NET MVC5 Demo project to ASP.NET Core, and found that the way we used to read Web.config by ConfigurationManager.AppSettings[] is no longer working. .NET Core has many new ways to achieve this. I picked one that suitable for my project. Here is how I do it. The Classic ASP.NET Code web.config ... ......

ASP.NET .NET Core

Windows 10 UWP开发:拼音首字母分组如何去掉“拼音”前缀并支持切换系统语言

Windows 10里面有个脑残设计,就是系统默认的CharacterGroupings类型在中文版系统上会产生除了A-Z字母以外的带“拼音”前缀的另外24个分组。比如开屎菜单里就是这样: 如果我们用这个CharacterGroupings类型去创建带分组的ListView,就会变成这样: 更蛋疼的是,如果用户的系统是英文语言的,他就会发现分组变成空白了,没有任何数据。用户不知道这是微软干的,又得给我们的APP打1星,还要骂我们傻逼。 今天经过研究,终于把这个问题给解决了,不仅去掉了“拼音”前缀,也不用担心用户系统是什么语言的,都能正常显示分组列表。 我们先看看原来的代码。 public class AlphaKeyGroup : List { const string GlobeGroupKey = "?"; public string Key...

Windows 10 UWP

Sharing Images in Windows 10 UWP

Starting from Windows 8, one big feature for Windows Store Apps is to share data using Charm Bar across Apps. Although the Charm Bar is removed in Windows 10, but the API for sharing is still in the fight.  For example, in my "Image Portray" App, I can share ink to OneNote or Outlook. Today, I added same capability for my "Shanghai Metro" App. Here's how to do it. First, to share data across Wi...

Windows 10 UWP

Raspberry Pi Surveillance Camera with Linux and Azure

Because Windows 10 IoT Core is not supporting Pi Camera, I can only use Linux instead. These days, I made a surveillance camera, the functionality is simple, when a person passed by the camera, it will take a picture and upload to Microsoft Azure Storage. It also got a website to remotely view the photos. 1. Hardware A PIR Sensor, a Pi Camera, a couple of jump wires. Connect the Singal port of t...

Azure IoT Raspberry Pi Linux Pi Camera Python

Uploading PiCamera images to Azure

Recently Windows 10 IoT Core Build 14393 is coming, but still without PiCamera support, WTF. So I can only choose Linux for my project. When I was using Windows, I use C# + Azure SDK to upload photos to Microsoft Azure. So how to do it on Linux? After some research, here's how to do it. My system is Raspbian Linux. First, we need to install Azure SDK in SSH Terminal: sudo pip install --pre azur...

Azure Linux Pi Camera Python