MSI：在安装的UI阶段显示消息框

Question

I'm updating an InstallShield based installer. I've added a new managed custom action, written in C#, and packaged using Wix DTF. Action is invoked correctly, and performs necessary actions.

Problem I have is showing an error message to user.

Method 1: MsiProcessMessage

From articles I've read, I understood that MsiProcessMessage is the correct way to do it, however this method does not work in UI sequence (before setup actually starts copying files and modifying system). In install sequence this method works. Code which I use is following:

Record record = new Record() { FormatString = "Password is not valid for this user." };
session.Message(
    InstallMessage.Error | (InstallMessage)(MessageBoxIcon.Error) | (InstallMessage)MessageBoxButtons.OK,
    record
);

Is it actually impossible to show an error message in UI sequence (Immediate execution) using MsiProcessMessage ?

Method 2: MessageBox.Show

Using Windows.Forms works for showing a message box. However, message is displayed in background of setup wizard, and shows a separate icon in Windows taskbar.

Is there a way to get window handle of installation wizard, and that way solve this problem?

Answer 1

You didn't quite mention this, but I'm guessing that you are invoking your custom action off a DoAction ControlEvent , published off of something like a button click. Underneath the covers, this is very different from scheduling it in the InstallUISequence . MsiProcessMessage doesn't work from DoAction .

For proper integration with the Windows Installer UI experience, you should avoid using MessageBox.Show (your method 2). Better-integrated options include:

• Tweaking a message that can be shown on the dialog from which you invoke this action
• Showing a popup message by conditionally invoking a SpawnDialog ControlEvent
• Showing an additional wizard panel by conditionally invoking a NewDialog ControlEvent

All three of those involve editing the UI of your project, but differently.