Привет, сейчас я нашел решение:
public BindableProperty GetBindableProperty(BindableObject bindableObj, string propertyName) {
Type type = bindableObj.GetType();
FieldInfo fieldInfo;
while(null == (fieldInfo = type.GetField(propertyName + "Property", BindingFlags.Static | BindingFlags.Public))) {
type = type.BaseType;
}
if(null == fieldInfo) {
throw (new Exception("Can not find the BindableProperty for " + propertyName));
}
return ((BindableProperty)(fieldInfo.GetValue(bindableObj)));
}