All Posts in 2017


Show Confirm Dialog When User Close UWP App

When our UWP Application deal with user data in it, e.g. like drawings or documents, we usually want to make sure user won't close the App by accident and lose their work. Just like what you see in a Office application, it will ask you if you want to save your document before close the App. For a long time, UWP could not do that in a normal way. Because it is not a general public API and it is …


Windows 10 秋季更新上用编程方式重启UWP应用

有时候,我们的UWP应用会要求用户重启,以应用一些设置。通常情况下,用户只能手工关闭App并再次打开完成重启的步骤。其实,在Windows 10秋季更新里,开发者已经可以通过编程方式,让用户一键完成自动重启App的工作。 比如我的“Character Map UWP”这个应用,在用户更改设置后,需要重启生效。那么第一步,就是在设置页面加一个重启按钮“Restart Now”: <Button x:Name="BtnRestart" Content="Restart Now" Click="BtnRestart_OnClick" /> 然后,我们需要通过秋季更新中的全新牛逼API RequestRestartAsync(String) 来完成重启。 这个API的签名如下: public static …


Install Linux Subsystem on Windows 10 Fall Creators Update

In the recent Windows 10 v1709 Fall Creators Update, the Windows subsystem for Linux has been improved a lot. Let's see how easy it is now to install Linux on Windows. 1. Enable Windows Subsystem for Linux Because the classic control panel has been hidden, now the quickest way to access Programs and Features is to run appwiz.cpl And then check "Windows Subsystem for Linux" under "Turn …


Use ICMP Ping in .NET Core 2.0

In classic .NET Framework applications, we have used System.Net.NetworkInformation.Ping class to Ping a host address. This API is not included by default in .NET Core, even in version 2.0. Here is how to do it in a .NET Core way. First, we need to reference a package System.Net.Ping Install-Package System.Net.Ping This will give us the same API set as .NET Framework. Then, in your .NET …


Use NLog in ASP.NET Core 2.0

There's official update for NLog targeting ASP.NET Core 2.x, for the latest methods please refer to https://github.com/NLog/NLog.Web/wiki/Getting-started-with-ASP.NET-Core-2 Recently I am porting a classic ASP.NET MVC 5 project to .NET Core 2.0, in order to run it on Linux. One of the parts that has differences between .NET Fx and .NET Core is logging. I choose NLog as my logging providor, …


Automatically Set Text Color on Accent Background in UWP

Windows 10 allows users to set accent color for the system, and in UWP apps, we usually honor those settings by using XAML pre-defined resource keys like {ThemeResource SystemControlBackgroundAccentBrush}. But regardless of how the user set default app mode to dark or light, when we apply text on accent colors, it may have some problems. For example, when the App is in light mode, the …


Get Client IP Address in ASP.NET Core 2.x

In classic ASP.NET we used to get client IP Address by Request.UserHostAddress. But this does not apply to ASP.NET Core 2.0. We need a different way to retrieve HTTP Request information. 1. Define a variable in your MVC controller private IHttpContextAccessor _accessor; 2.  DI into the controller's constructor public SomeController(IHttpContextAccessor accessor) { _accessor = …


Configure VSTS Build for UWP Apps

UWP Apps usually require a lot of time to compile a "release" package for submitting to Windows Store, and if you are working in a team, TFS/VSTS can help your team ensure that each check-in has a success build, and make it easier for deployment and testing. Let's see a basic example of how to setup a CI build for a UWP App on VSTS. Important Pre-condition: Before you do that, please …


Windows 10 UWP: Switching Languages in Your App

By default, a UWP App's UI language is automatically fits the system current language settings. However, what if the user need the ability to set a particular UI language just for your App without having to change system language? In my App, I supports Simplified Chinese and English. The user can override the system language in App's settings page: So how to do it? First, you need to have …


Windows 10 UWP: How to Read and Save Settings Easily

In the UWP Application model, reading and saving settings are very similar to WinRT API. The class we are using is ApplicationData.Current.LocalSettings It is using key-value-pair to store settings. LocalSettings will stay on the user's current computer, and not being synced with thier Microsoft account. The API to save settings is: LocalSettings.Values[key] = value; To read settings:  …


Windows 10 UWP: How to Debug OnFileActivated Launch Failure

Today I am working on my Image Portray App, and I get my code blown up. The problem is, when the App is already started, it can open .ink file with double click from a file. But when the App is not launched, opening a .ink file to start the App will make it crash. As other UWP that supports file type association, I also use OnFileActivated event to launch my App. This kind of problem could …


10 Tricks and Tools for Windows 10 UWP Development

After Windows 10's launch. More and more UWP applications are coming as well as more Windows developers. I am doing UWP development besides my job for more then 2 years. Today, I will share some tips and tricks from my UWP development experience as well as some handy tools, so that you can do your development more quicker and easier. 1. Automatically Set Color to Title Bar The default color …


Windows 10 UWP: Undo / Redo Ink with Surface Dial

The Surface Dial is the first wheel device in a new input device class. I got my hand on one as soon as it came to market in China. I have a UWP App named "Image Portray", as a drawing app that can make use of the Surface Dial. One of it's useful application to undo / redo the ink by turning the Surface Dial. You can download it from Windows Store these days to see the changes. So, let's begin …


Windows 10 UWP: Undo / Redo on InkCanvas

The InkCanvas in UWP only got pens by default, it can not perform Undo or Redo. To implement this, we will need to code for ourselves. Official document covered Undo functionalilty, but not redo. Today, I have successfully done it, and I'd like to share with you. First, you need to add two custom buttons on the InkToolbar for Undo / Redo <InkToolbarCustomToolButton Name="undoButton" …


Remote Deploy and Debug UWP Apps

These days I am developing an App that need to be tested on multiple languages environment. I can set my local dev box to different language, and restart or sign out / sign in to Windows again to test different languages. But this is very inconvenient. I want to setup a Windows 10 virtual machine with Chinese language and let Visual Studio 2017 deploy and debug the App right into the VM. …


微软 Build Tour 2017 上海一日游

Build是微软从2011年开始举办的开发者大会。我作为一个使用微软技术的开发者,当然每年都不会错过这样的一场盛宴。然而,Build的主会场永远都是在美国,这让其他国家的信徒们无法接近我大微软。于是,从2015年起,微软会在Build结束之后,到世界各国的主要城市开设免费巡演活动,内容都是Build大会的精选。 图为我当年在家里用电视观看Build 2011   我曾经在2015年参加过微软在上海的Build Tour,留下了非常深刻的好印象。于是今年,我当然不能错过Build 2017 Tour的上海场了。今年的Tour有2天,第一天是Session第二天是编程马拉松,我怕技术被人鄙视,所以只报名了第一天的内容。 今年微软在中国确实更给力了,这次的Tour是紧接着Build 2017午夜啪活动之后的。中国午夜啪的其中几位主持人也来到了Build Tour,都是软狗们 …


Migrate Domain DNS to Azure

It has been a while since Azure DNS went GA on Azure. It's like "dnspod" in China, offers a third party DNS services besides your domain register. The power of Azure has already been witnessed by the entire human race. Now that, it has got DNS services, it would surly be the best in class DNS on the planet. Thus, what we have to do, is to migrate our DNS servers to Azure DNS. So that …


Configure Continuous Delivery for ASP.NET Core Website on Azure

Today I am trying new DevOps tools in VS2017 and Azure, my goal is to automate the process from development to production for an exsiting ASP.NET Core project. I have encountered some issues, and with the help of Microsoft Support, I was able to solve them and share with you guys. First, there are two ways to configure CD for Azure Web Apps. I prefer create a website first, then configure it …


How to Save InkCavas to Image in Windows 10 UWP

The InkCanvas control in Windows 10 UWP is not like WPF where you can save as image file easily. If you want to save user ink to an image file, there's by far only one way to do it: 1. Install Win2D.UWP via NuGet into your project. PM> Install-Package Win2D.UWP 2. Because we need to access user's picture library, so we need to apply the permission in manifest file. Select "Pictures …


Azure Fire Alarm by Raspberry Pi and Windows 10 IoT Core

防火是日常生活中非常重要的意识,如果你是一只恩爱狗,出门在外,家里被FFF团点了,那真是太惨(hao)了。如果你恰好有Windows 10的设备,比如Lumia,Surface,能及时收到火警是至(mei)关(sha)重(luan)要(yong)的。今天就教大家如何用Microsoft Azure公有云+Windows 10 IoT Core在树莓派上实现一个远程火警系统。 阅读这篇文章,你需要的前置知识: Windows 10,UWP的基本开发能力 MVVM基础知识 ASP.NET MVC的基础知识 树莓派、GPIO及逻辑电路的基本知识(也就是大学里的计算机电路) Azure公有云的使用经验 ……当然,还要有对微软的信仰 一、设计原理 基本想法是,通过火焰传感器的输入信号,触发一个警报,把消息发送到Azure上的Notification …


Create QR Code in Windows 10 UWP

A year ago, I wrote an UWP application that can generate QR Code. However, at that time, the QR Code library I used was ZXing.Net, the last update for this package was in 2014. Now, time has changed, the author of ZXing.Net seems not to update the package any more. However, we have to move on, so I found a fantastic new library to generate QR Code in .NET applications: QRCoder To use that …


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 …


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", " …