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Navigation: HelpXplain for Developers

Dynamic eWriter and Ziphelp help files

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If you save an Xplain as an eWriter or Ziphelp help file you can also control it from your application or the command line with a series of simple commands.

Installing the eViewer.exe app with your software

To make your calls to your help files you need to be able to reference the viewer directly, so it is best install it along with your software instead of depending on the Windows Store version of the app, which may or may not be installed on the user's computer. If you are targeting MacOS, you must always install the app yourself.

The eViewer.exe viewer program included with HelpXplain in the program directory is a single file that is already digitally signed. You just need to install it along with your software and then you can use it to open and display .ewriter help files as explained below.

If you wish you can also rename the viewer file and re-sign it with your own certificate so that it matches the rest of your software. That is entirely up to you and we don't have a problem with it.

Note that this method also works for users on Windows 7 and XP, where the App Store version of eWriter Viewer can't be installed. The version included with HelpXplain is the universal version that is also compatible with Windows XP and all later versions.

Downloadable installer for the eViewer app

You can also provide a link to the downloadable installer for the eViewer app. The 32-bit and 64-bit windows eViewer installers and the MacOS installer for end users are always available on the eWriter website at:


Same syntax for eWriter and Ziphelp

Note that the syntax is identical for both eWriter and Ziphelp files. The only difference in your calls will whether the file being called has the .ewriter or .zhelp extension.

About eViewer app instances

Each individual eWriter or Ziphelp file you open has one and only one instance. If you make another call to the same help file it will apply to the open instance. You can have multiple help files open at the same time. To address the individual files you include the name of the file in your call along with the parameters, as shown below.

Call syntax using the eViewer app on Windows

Note that the syntax is identical for both eWriter and Ziphelp files. For deployment for MacOS, please see the documentation in the eWriter as Application Help package available on the eWriter web page here:

To make calls to your help you just need to call the eViewer.exe app using your programming language's function for executing external programs (ShellExecute and similar functions). This is followed by two parameters: the name of the help file and the HTML page in the file you want to view. Both parameters need to be in double quotes.

<path>eViewer.exe "<path>my_help.ewriter" "index.html"

<path>eViewer.exe "<path>my_help.ewriter" "this_page.html#anchor"

<path>eViewer.exe "<path>my_help.ewriter" "this_page.html?mysetting=xyz"

<path>eViewer.exe "<path>my_help.ewriter" "subfolder/anotherpage.html"

For Ziphelp, just use the .zhelp extension for the target file instead of .ewriter.

Defining the size and position of the viewer with calls

You can override the position and size the viewer defined in the eWriter or Ziphelp file with the /defpos: switch in the command line.


All four parameters are decimal integers. No spaces allowed. The x and y parameters are the position on the screen. The width and height parameters are the dimensions of the viewer. The position parameters are required, the dimension parameters are optional.


<path>eViewer.exe "<path>my_help.ewriter" /defpos:50,50

<path>eViewer.exe "<path>my_help.ewriter" /defpos:50,50,700,900

For Ziphelp, just use the .zhelp extension for the target file instead of .ewriter.

The first example opens the help file with its standard dimensions but positions its top left corner at x = 50 and y = 50 pixels. The second example also overrides the dimensions, setting the viewer to be 700 pixels wide and 900 pixels high (virtual pixels on hi-resolution devices).

Including the password for protected eWriter help files

If your help file is protected with a password you can include it in the call with the /pw: switch so that the user does not need to enter it. However, be aware that doing this is not secure: Windows saves the parameters of every program execution and it is quite easy for a professional to get the password on a computer where this has been done.

<path>eViewer.exe "<path>my_help.ewriter" /pw:password 

For Ziphelp, just use the .zhelp extension for the target file instead of .ewriter.

Closing the eViewer app from your program

You can close the instance of the eViewer app from your program with the close command as an individual parameter at the end of the command line. Here too, you need to address the help file instance that you have opened to close it.

<path>eViewer.exe <path>myhelp.ewriter  -> opens help file 1

<path>eViewer.exe <path>otherhelp.ewriter   -> opens help file 2 in a second window

<path>eViewer.exe <path>myhelp.ewriter close   -> closes window 1 with help file 1

<path>eViewer.exe <path>otherhelp.ewriter close  -> closes window 2 with help file 2

For Ziphelp, just use the .zhelp extension for the target file instead of .ewriter.