This tool compiles all Qt ui files that exists in the same directory.

Ui.tt

<#
// Ui.tt - Qt ui file compilation tool for T4 Template -
// This tool compiles all Qt ui files that exists in the same directory.
// ---------------------------------------------------------------------------- 
// Copyright 2013 terurou (terurou at gmail.com)
// 
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#>
<#@ template debug="false" hostspecific="true" language="C#" #>
<#@ output extension=".txt" #>
<#@ assembly name="System.Core" #>
<#@ assembly name="System.Xml" #>
<#@ assembly name="System.Xml.Linq" #>
<# // assembly name="EnvDTE" #>
<#@ assembly name="C:\Program Files (x86)\Common Files\microsoft shared\MSEnv\PublicAssemblies\envdte.dll" #>
<#@ assembly name="Microsoft.VisualStudio.OLE.Interop" #>
<#@ assembly name="Microsoft.VisualStudio.Shell" #>
<#@ assembly name="Microsoft.VisualStudio.Shell.Interop" #>
<#@ assembly name="Microsoft.VisualStudio.Shell.Interop.8.0" #>
<#@ import namespace="System.IO" #>
<#@ import namespace="System.Linq" #>
<#@ import namespace="System.Xml.Linq" #>
<#@ import namespace="System.Diagnostics" #>
<#@ import namespace="Microsoft.VisualStudio.Shell" #>
<#@ import namespace="Microsoft.VisualStudio.Shell.Interop" #>
<#@ import namespace="Microsoft.VisualStudio.TextTemplating" #>
<#
var projectItem = GetTemplateProjectItem();

projectItem.ProjectItems
    .Cast<EnvDTE.ProjectItem>()
    .ToList()
    .ForEach(x => x.Delete());

Directory.EnumerateFiles(Path.GetDirectoryName(Host.TemplateFile), "*.ui")
    .ToList()
    .ForEach(src => {
        var dist = src + ".cs";
        using (var process = new Process())
        {
            process.StartInfo = new ProcessStartInfo()
            {
                FileName = "uics.exe",
                Arguments = string.Format("-o \"{1}\" \"{0}\"", src, dist),
                UseShellExecute = false,
                CreateNoWindow = true,
            };
            process.Start();
            process.WaitForExit();
        }
        projectItem.ProjectItems.AddFromFile(dist);
    });
#>
<#+
EnvDTE.ProjectItem GetTemplateProjectItem()
{
    var project = GetVSProject();

    var found = 0;
    var itemId = 0u;
    var ret = 0; 
        
    ret = project.IsDocumentInProject(Host.TemplateFile, out found, new VSDOCUMENTPRIORITY[1], out itemId);
    if (ret != VSConstants.S_OK || found == 0 || itemId == 0) throw new Exception();

    Microsoft.VisualStudio.OLE.Interop.IServiceProvider context = null;
    ret = project.GetItemContext(itemId, out context);
    if (ret != VSConstants.S_OK || context == null) throw new Exception();
    
    var provider = new ServiceProvider(context);
    return provider.GetService(typeof(EnvDTE.ProjectItem)) as EnvDTE.ProjectItem;
}

IVsProject GetVSProject()
{
    var dte = (Host as IServiceProvider).GetService(typeof(EnvDTE.DTE)) as EnvDTE.DTE;
    var project = ((Array)dte.ActiveSolutionProjects).GetValue(0) as EnvDTE.Project;
    var guid = XDocument.Load((project.FileName))
        .Descendants()
        .First(x => x.Name.LocalName == "ProjectGuid")
        .Value;
    
    return VsShellUtilities.GetHierarchy(
        new ServiceProvider((Microsoft.VisualStudio.OLE.Interop.IServiceProvider)project.DTE),
        new Guid(guid)) as IVsProject;
}
#>