方法一

1、在WPF项目中增加一个新的类文件，粘贴如下代码：

 public static class ConsoleManager
    {
        private const string Kernel32_DllName = "kernel32.dll";
        [DllImport(Kernel32_DllName)]
        private static extern bool AllocConsole();
        [DllImport(Kernel32_DllName)]
        private static extern bool FreeConsole();
        [DllImport(Kernel32_DllName)]
        private static extern IntPtr GetConsoleWindow();
        [DllImport(Kernel32_DllName)]
        private static extern int GetConsoleOutputCP();
        public static bool HasConsole
        {
            get
            {
                return GetConsoleWindow() != IntPtr.Zero;
            }
        }
        /// Creates a new console instance if the process is not attached to a console already.  
        public static void Show()
        {
#if DEBUG
            if (!HasConsole)
            {
                AllocConsole();
                InvalidateOutAndError();
            }
#endif
        }
        /// If the process has a console attached to it, it will be detached and no longer visible. Writing to the System.Console is still possible, but no output will be shown.   
        public static void Hide()
        {
#if DEBUG
            if (HasConsole)
            {
                SetOutAndErrorNull();
                FreeConsole();
            }
#endif
        }
        public static void Toggle()
        {
            if (HasConsole)
            {
                Hide();
            }
            else
            {
                Show();
            }
        }
        static void InvalidateOutAndError()
        {
            Type type = typeof(System.Console);
            System.Reflection.FieldInfo _out = type.GetField("_out",
                System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic);
            System.Reflection.FieldInfo _error = type.GetField("_error",
                System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic);
            System.Reflection.MethodInfo _InitializeStdOutError = type.GetMethod("InitializeStdOutError",
                System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic);
            Debug.Assert(_out != null);
            Debug.Assert(_error != null);
            Debug.Assert(_InitializeStdOutError != null);
            _out.SetValue(null, null);
            _error.SetValue(null, null);
            _InitializeStdOutError.Invoke(null, new object[] { true });
        }
        static void SetOutAndErrorNull()
        {
            Console.SetOut(TextWriter.Null);
            Console.SetError(TextWriter.Null);
        }
    }

2、调用

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            ConsoleManager.Show();//打开控制台窗口
            Console.ForegroundColor = ConsoleColor.Red;
            Console.WriteLine("这是测试信息");
        }

3、更改项目属性

• 右击项目，在应用程序选项卡中暂时切换输出类型为：控制台应用程序
  

4、运行效果

方法二：使用Trace

1、直接使用Trace

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            Trace.WriteLine("这是测试信息");
        }

2、效果