Xamarin表格-如何獲得屏幕亮度和串行端口？

Question

我想創建一個頁面，顯示設備的所有硬件，包括亮度和串行端口。 我應該怎么做？

Answer 1

如果要獲得亮度 ，使用DependencyService將是一個好方法。

首先實現接口：

public interface IBrightnessService
{
    void SetBrightness(float factor);
    float GetBrightness();
}

然后在要獲取或設置方法的窗體中：

組：

var brightnessService = DependencyService.Get<IBrightnessService>();
brightnessService.SetBrightness((float)0.5);

得到：

var brightnessService = DependencyService.Get<IBrightnessService>();
Console.WriteLine("brightness is:" + brightnessService.GetBrightness());

在Android中，創建AndroidBrightnessService ：

[assembly: Xamarin.Forms.Dependency(typeof(AndroidBrightnessService))]
namespace App6.Droid
{
    public class AndroidBrightnessService : IBrightnessService
    {
        [Obsolete]
        public float GetBrightness()
        {
            //throw new NotImplementedException();
            //var window = ((Activity)Forms.Context).Window;

            //var attributesWindow = new WindowManagerLayoutParams();

            //attributesWindow.CopyFrom(window.Attributes);

            var brightness = Android.Provider.Settings.System.GetInt(MainActivity.thisMainActivity.ContentResolver, Android.Provider.Settings.System.ScreenBrightness);
            //MainActivity.thisMainActivity is a isntance from activity
            //The returned brightness is an int type value between 0 and 255.
            return brightness;
        }

        [Obsolete]
        public void SetBrightness(float brightness)
        {
            //throw new NotImplementedException();
            var window = ((Activity)Forms.Context).Window;
            //var window = CrossCurrentActivity.Current.Activity.Window;
            var attributesWindow = new WindowManagerLayoutParams();

            attributesWindow.CopyFrom(window.Attributes);
            attributesWindow.ScreenBrightness = brightness;

            window.Attributes = attributesWindow;
        }
    }
}

注意：MainActivity.thisMainActivity是來自活動的一個概念：

public static MainActivity thisMainActivity;

onCreate方法：

thisMainActivity = this;

在IOS中，Cretae iOSBrightnessService ：

[assembly: Dependency(typeof(iOSBrightnessService))]
namespace App6.iOS
{
    public class iOSBrightnessService : IBrightnessService
    {
        public float GetBrightness()
        {
            //throw new NotImplementedException();
            return (float)UIScreen.MainScreen.Brightness;
        }

        public void SetBrightness(float brightness)
        {
            //throw new NotImplementedException();
            UIScreen.MainScreen.Brightness = brightness;
        }
    }
}

注意：App6是我的項目的名稱。

================================================== ===========================

關於串行端口 ，我沒有在我的項目中使用過，但是它應該只存在於android中。我認為這需要在DependencyService的基礎上由某些庫（例如.so文件）引用。

這是一個可以參考的Nuget包（ Xamarin.Android.SerialPort ）。您可以查看一個示例項目 。