测试高亮

using System.Runtime.InteropServices;

[DllImport("kernel32.dll", EntryPoint = "GetSystemDefaultLCID")]
        public static extern int GetSystemDefaultLCID();
        [DllImport("kernel32.dll", EntryPoint = "SetLocaleInfoA")]
        public static extern int SetLocaleInfo(int Locale, int LCType, string lpLCData);
        public const int LOCALE_SLONGDATE = 0x20;
        public const int LOCALE_SSHORTDATE = 0x1F;
        public const int LOCALE_STIME = 0x1003; 

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                int x = GetSystemDefaultLCID();
                SetLocaleInfo(x, LOCALE_STIME, "HH:mm:ss");        //时间格式  
                SetLocaleInfo(x, LOCALE_SSHORTDATE, "yyyy-MM-dd");   //短日期格式    
                SetLocaleInfo(x, LOCALE_SLONGDATE, "yyyy-MM-dd");   //长日期格式   
                MessageBox.Show("OK");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }  
        }