31
OCT
.NET and Azure Developer
ASP.NET
13
OCT
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 …
12
OCT
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 traditional 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. …
19
SEP
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 …
18
SEP
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 …
16
OCT
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 = accessor; …
06
APR
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 from …
09
OCT
Read AppSettings in ASP.NET Core 2.x
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 Controller private static CloudBlobContainer GetBlobContainer() …
22
APR
如何高逼格读取Web.config中的AppSettings
先插句题外话，下版本的ASP.NET貌似把web.config撸掉了，都变成json了。所以本文讨论的内容可能以后用不到了，但是一些设计思想还是可以用的~ 直接进入正题，在ASP.NET网站里（也包括其他有web.config, app.config）的.NET工程里，读AppSettings的值是个很常见的场景。比如： 在代码里读的时候就会用到： ConfigurationManager.AppSettings["EnableAzureWebTrace"]; 这个[]索引器返回的是string类型。所以下一步我们通常需要类型转换才能在代码里拿来用。比如这个例子里，我们就要转换成bool。其他时候，可能要转换为int等类型。 string enableAzureWebTraceConfig = ConfigurationManager.AppSettings[" …
18
JUL