wix 如何在线安装.Net Client 4

困扰了很久，网上的方法大多是用burn，后来找到了robmen的博客，看到里面的一篇文章，差点绝望了

Download - redistributables (think .NET Framework and SQL Express) that are larger than the applications 
which use them are unfortunately really common right now. If you are distributing your application over 
the Internet (and how many people today aren't?) shipping those redistributes in your setup is expensive. 
Burn has the ability to only download what the user needs and/or chooses to install. That means if the 
.NET Framework is already installed, no need to download it again. Also, when your product is broken 
up into multiple MSI files it becomes possible to optimize the distribution further. Oh, and did I mention 
Burn will support resume if the download server supports HTTP 1.1? 

要写WPF好幸苦，其实需求就一个，不要这么大的安装包。想了很久，最后只能一个个API去读，终于还是找到了方法：

<Target Name="AfterBuild">
    <GenerateBootstrapper ApplicationFile="$(TargetFileName)" 
         ApplicationName="Landow" 
         BootstrapperItems="@(BootstrapperFile)" 
         ComponentsLocation="HomeSite" 
         CopyComponents="false" 
         OutputPath="$(OutputPath)" 
         Path="$(BootstrapperPath)" 
         ComponentsUrl="http://go.microsoft.com/fwlink/?linkid=182804"/>
</Target>

这里附带一点资料：

<Product> Element (Bootstrapper)

GenerateBootstrapper Task

版本和設定檔	架構	安裝程式檔案名稱	URL
.NET Framework 4.5.1	x86 x64	NDP451-KB2858728-x86-x64-AllOS-ENU.exe	http://go.microsoft.com/fwlink/?LinkId=321332
.NET 4.5 Framework	x86 x64	dotNetFx45_Full_x86_x64.exe	http://go.microsoft.com/fwlink/?LinkId=255995
.NET Framework 3.5 SP1 中，.NET Framework 3.0 SP2，.NET Framework 2.0 SP2 (如果已經安裝.NET Framework 3.0 和 3.5)	x86 x64	dotnetfx35.exe	http://go.microsoft.com/fwlink/?LinkId=259762
.NET Framework 4 用戶端設定檔	x86	dotNetFx40_Client_x86.exe	http://go.microsoft.com/fwlink/?linkid=247966
.NET Framework 4 用戶端設定檔	x86 x64	dotNetFx40_Client_x86_x64.exe	http://go.microsoft.com/fwlink/?linkid=247965
.NET Framework 4 完整	x86	dotNetFx40_Full_x86.exe	http://go.microsoft.com/fwlink/?linkid=247964
.NET Framework 4 完整	x86 x64	dotNetFx40_Full_x86_x64.exe	http://go.microsoft.com/fwlink/?linkid=247962
.NET Framework 2.0 SP2 (當未安裝版本 3.0 和 3.5)	x64	NetFx20SP2_x64.exe	http://go.microsoft.com/fwlink/?LinkId=259767
.NET Framework 2.0 SP2 (當未安裝版本 3.0 和 3.5)	x86	NetFx20SP2_x86.exe	http://go.microsoft.com/fwlink/?LinkId=259766