Friday, February 15, 2019

Accessing web site running in Visual Studio 2017 using an alternative hostname


  • Running in Visual Studio 2017
  • Running an application on port 8888
  • Url used to access the application is http://localhost:8888

If you want to access the web site using http://somenamehere:8888 you can do this by doing the following.

  1. Open your .vs/config/applicationhost.config file in a text editor
  2. Find the binding for your application.
    <binding protocol="http" bindingInformation="*:8888:localhost" />
  3. In the same <bindings> section, add another <binding>
    <binding protocol="http" bindingInformation="*:8888:" />
  4. Optional: If you are using https you will need to do the same. The key is that you match the ports.
You should be able to launch your web site in Visual Studio (Control-F5, etc). This will bring it up as it always have.

Now you need to hack your dns so that it can resolve your new made up hostname. In this example, it is somenamehere. The easiest way to do this is to open up your hosts file (C:\Windows\System32\drivers\etc\hosts) in a text editor and add the following line to the bottom of it.   somenamehere

You should now be able to ping that hostname and see that is responding.

Now open up the browser and go to http://somenamehere:8888 and you should get your application again.

NOTE: If VS2017 gives you any issues, it may be helpful to run it as administrator.

Thursday, February 14, 2019

Changing Styles for print media query

I had a situation where I needed to change what would be printed based on what button on the web page the user clicked. Here is an easy way to do that.

<style type="text/css" media="print" id="printStyles">

    function printOptionA() {
        var styles = "#optionA {display: block;} #optionB {display:none;}";

 function printOptionB() {
        var styles = "#optionB {display: block;} #optionA {display:none;}";

The two functions can be called from button, hyperlinks, etc.

If the user just does a Control-P to print in the browser it will print the page as expected (neither of these changes). There is no need to undo these changes after printing.

Wednesday, February 13, 2019

Changing the first line preview in email clients

In many email clients it will now show you the first line of the email body before you open it. If you are a developer creating this email sometimes it shows things like a url of a header image instead of something more useful. The good news is you can trick the email clients into displaying whatever you want. Just make sure the first thing in your body tag (can be after the style tag, etc) is the following:

<div style="display: none; mso-hide: all; width: 0px; height: 0px; max-width: 0px; max-height: 0px; font-size: 0px; line-height: 0px;">
    Whatever you want to see in the preview here

Tuesday, November 20, 2018

Keeping Secrets out of the web.config

See here for Microsofts official recommendations on best practices to keep secrets out of the web config.

I am mostly concerned about appSettings and connectionStrings sections in the web.config

The Microsoft article says everything I am going to say below, but they are some important points to consider.


To keep your appSettings secret, put them in another file that is not checked into source control. The contents of this file will be merged with what is in the web.config so this works well to allow developers to override values in appSettings.

The syntax is basically

<appSettings file="..\..\AppSettingsSecrets.config"> <add key="webpages:Version" value="" /> <add key="webpages:Enabled" value="false" /> <add key="ClientValidationEnabled" value="true" /> <add key="UnobtrusiveJavaScriptEnabled" value="true" /> </appSettings>

The file attribute accepts paths that are relative or absolve and the file does not have to exist. This is useful when deploying to different environments that may not use this file and instead use VSTS / replacing of tokens to manage values per environment.


The connectionStrings section isn't as nice as the appSettings. The tags between connectionString tags are replaced by the contents of the external file. The file referenced MUST be in the same directory as the web.config that is referencing it. This means the secret file is per project. The other thing that makes it not work as easily is that it MUST exist otherwise you will get a build error because the project file will try to find the file. You can edit the project file and tell it to only include the file in the project for particular environments, but that is tedious and must be done on each project file.

Thursday, November 8, 2018

Save objects in Visual Studio for reuse later

One easy way to save an object while debugging in Visual Studio so that you can use it later for troubleshooting, or maybe use in LINQPad is to serialize the object to disk.

All the libraries you need are built into .NET and can be done in the Immediate Prompt in Visual Studio.

Save the Object to disk

string json = new System.Web.Script.Serialization.JavaScriptSerializer().Serialize(myObject);
System.IO.File.WriteAllText($@"c:\dev\{nameof(myObject)}.json", json);

Read the Object from disk

string json = System.IO.File.ReadAllText(@"c:\dev\myObject.json");
var company = new System.Web.Script.Serialization.JavaScriptSerializer().Deserialize<MyClass>(json);

The caveat to this is that you will need the MyClass available when you bring it back to life.You can also pass Object instead of MyClass if you don't have it.

Wednesday, August 22, 2018

Running IISExpress from the command line or Powershell

You don't need to open up Visual Studio just to run another project. You can run IISExpress via the command line instead.

Here is the same example, once for the command prompt and again for Powershell. The name of the site can be found in the applicationhost.config file. You'll see a <site> tag and the name attribute is the siteName. This is also the name that shows up in the system tray when you launch the site in Visual Studio itself.

You can use the system tray IIS Express icon to quit instances started using Powershell or command prompt. You can also type a the letter Q at the command prompt that gets spawned.

Command Prompt

"C:\Program Files (x86)\IIS Express\iisexpress.exe" /config:"C:\dev\MyMvcApp\.vs\config\applicationhost.config" /site:"MyMvcApp"

You'll need to tweak this to match your paths, etc.


$scriptDir = Split-Path $script:MyInvocation.MyCommand.Path

function Start-IisExpress($config, $siteName) {
    Start-Process -FilePath 'C:\Program Files (x86)\IIS Express\iisexpress.exe' -ArgumentList "/config:$config /site:$siteName"

Start-IisExpress -config "$scriptDir\.vs\config\applicationhost.config" -siteName: "MyMvcApp"

NOTE: This assumes that you have put this in a Powershell (.ps1) file and placed it next to your solution and more importantly that the .vs directory is in the same directory as the .ps1 file. If not, you'll need to adjust the path or hard code the full path.

Tuesday, June 19, 2018

Fixing build issues

It can be hard to work out exactly where the problem is via visual studio directly. You can use the following to leverage msbuild and get more accurate information.

From a  cmd prompt run:

msbuild /verbosity:d > build.txt