WPF设置主窗口
<Application x:Class="testWpf.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
StartupUri="Window2.xaml">
<Application.Resources>
</Application.Resources>
</Application>
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
StartupUri="Window2.xaml">
<Application.Resources>
</Application.Resources>
</Application>
可以在App.xaml文件中设置StartupUri属性来决定哪个窗口是主要窗口
