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Xamarin C# code to access system properties via Android's hidden SystemProperties class
using System;
namespace Os.Properties
{
// Get access to the hidden SDK class SystemProperties. The SystemProperties
// class provides access to the System Properties store. This store contains
// a list of key-value pairs
// See https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/os/SystemProperties.java
public static class SysProp
{
// Lazy load the SystemProperties class
private static Lazy<Java.Lang.Class> _class =
new Lazy<Java.Lang.Class>(() =>
Java.Lang.Class.ForName("android.os.SystemProperties")
);
// Get the set method when we need it
private static Lazy<Java.Lang.Reflect.Method> _SetMethod =
new Lazy<Java.Lang.Reflect.Method>(() =>
_class.Value.GetDeclaredMethod("set",
Java.Lang.Class.FromType(typeof(Java.Lang.String)),
Java.Lang.Class.FromType(typeof(Java.Lang.String)))
);
// Get the get method when we need it
private static Lazy<Java.Lang.Reflect.Method> _GetMethod =
new Lazy<Java.Lang.Reflect.Method>(() =>
_class.Value.GetDeclaredMethod("get",
Java.Lang.Class.FromType(typeof(Java.Lang.String)))
);
private static Java.Lang.Reflect.Method SetMethod
{
get { return _SetMethod.Value; }
}
private static Java.Lang.Reflect.Method GetMethod
{
get { return _GetMethod.Value; }
}
/// <summary>
/// Calls the get method of the android.os.SystemProperties class
/// </summary>
/// <param name="PropertyName">The name of the system property to get the value for</param>
/// <returns>The value of the specified property or null if it does not exists</returns>
public static string GetProp(string PropertyName)
{
// Invoking a static method, first parameter is null
var r = GetMethod.Invoke(null, new Java.Lang.String(PropertyName));
return r.ToString();
}
/// <summary>
/// Calls the set method of the android.os.SystemProperties class
/// </summary>
/// <param name="PropertyName">The name of the system property to get the value for</param>
/// <param name="PropertyValue">The value to set for the system property</param>
/// <returns>The previous value of the specified property or null if it does not exists</returns>
public static string SetProp(string PropertyName, string PropertyValue)
{
// Invoking a static method, first parameter is null
var r = SetMethod.Invoke(null,
new Java.Lang.String(PropertyName),
new Java.Lang.String(PropertyValue));
return r.ToString();
}
}
}
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