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Build a Pixel Ruler with UWP

In certain applications, we may need an on-screen ruler that indicates pixels on the screen. However, the only built-in ruler in UWP is within the InkToolbar control, we are not able to use it elsewhere. So, I will teach you how to build a pixel ruler which can be used anywhere in your UWP applications. The Demo App Create a new blank UWP application called PixelRulerUwp with minimal runtime v...

UWP Win2D

Migrating Old ASP.NET Applications to .NET Core

More and more people are talking about .NET Core these days. It is true that .NET Core is the future, and .NET Framework will still be maintained because very large number of applications can’t be migrated in a short time. .NET Core and .NET Framework are just like electric cars and gasoline powered cars. Gasoline cars is mature, and you can drive it without any problem, but electric cars have th...

ASP.NET .NET Core .NET Framework

Generate Captcha Code in ASP.NET Core

If you want to use captcha code to protect your website from spam messages, there are a few options such as Google ReCaptcha and captcha.com. Both of them can be integrated into ASP.NET Core applications. However, you may still want to generate the captcha code yourself for some reason, such as your website may be used in mainland China... This post will show you how to generate and use captcha co...

ASP.NET .NET Core

Add Watermark to Uploaded Image in ASP.NET Core

Adding watermark to an image is very widely used in websites in order to protect the content owner's copyright, such as a blog system like this website. In triditional ASP.NET (.NET Framework), we could use System.Web.Helpers.WebImage to add text watermark like this: var image = new WebImage(imageBytes); image.AddTextWatermark( Settings.Instance.WatermarkText, "White", Settings.Instance.Wat...

ASP.NET .NET Core

Fix AcrylicBrush Missing on NavigationView in Windows 10 SDK 17763

Microsoft released a new version of Windows 10 UWP SDK Build 17763, you can check the What's New document for more details. But when I retarget my App to version 17763, something unexpected happens, the AcrylicBrush gone missing if I change my App runtime to version 17763. I am not sure if this is by design on 17763 or it is a bug, I am trying to contact Microsoft product group on this problem. F...

UWP

Get App Version in .NET Core

We can define versions on our .NET Core applications, but how to get the version at runtime? There are several ways to do it. First, let's see a typical .NET Core project file with versioning. We can define the version numbers for AssemblyVersion, FileVersion and Version in the project file (.csproj). The AssemblyVersion and FileVersion attributes must be in format of "m...

.NET Core

Send AntiForgeryToken via jQuery Ajax in ASP.NET Core

In ASP.NET Core, if we use jQuery Ajax to post data to the server, and we want the ValidateAntiForgeryToken attribute to work. We have to do some tricks. The official document didn't document how to do it via jQuery. Let me show you how to do it. Please do read the official document first: https://docs.microsoft.com/en-us/aspnet/core/security/anti-request-forgery?view=aspnetcore-2.1  In my pract...

AJAX ASP.NET jQuery .NET Core

Prevent Image Hotlinking in ASP.NET/Core Applications

Introduction As a website developer, we sometimes don't want the images on our own website to be directly referenced and showed on other's website. It can cause a lot network bandwidth for our datacenters in some cases, which means costing money for us to pay for the one who use our images. For example, your website is A.com, you have an image on http://a.com/facepalm.jpg and B.com used your ima...

ASP.NET IIS .NET Core

How to Fix Extended TitleBar Overlapping NavigationView PaneToggleButton

In UWP Apps, we some times extend our main view into title bar to get rid of Windows 10 default title bar. However if you are using NavigationView under extended title bar, you will find your PaneToggleButton overlapped by the title bar. And the user won't be able to click on the upper part of the button because it is where the title bar need to respond to window drag actions. This image shows th...

XAML UWP

Windows Community Toolkit: Use CameraPreview to Take Photos

In UWP Apps, if we want to use the device's camera to take photos and save to a file, it is used to be some how complicated, the developer need to know about quite a lot things and also write quite a few code to get it down (As you can find the Camera examples from Microsoft offical sample code). In fact, in many cases, we just want to take a photo by the most easy and default options via the came...

UWP Camera