Maui Xaml导入命名空间

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:controls="clr-namespace:RG3.MauiAppHostDemo.Controls"
             x:Class="RG3.MauiAppHostDemo.HomePage">

 xmlns:controls="clr-namespace:RG3.MauiAppHostDemo.Controls"