utility.cs

微软的行业应用解决方案示例

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.WindowsCE.Forms;
using System.Drawing;
using HardwareDistributor.Business;

namespace HardwareDistributor.Utilities
{
    public static class Utility
    {
        //this matches the value being used by the target window(splash screen) to wait for messages
        private const int WM_STATUSUPDATE = 0x0409;

        /// <summary>
        /// Internal method for checking a string for null or empty including 
        /// making sure it is not composed of spaces.
        /// </summary>
        /// <param name="stringToCheck">string to test</param>
        /// <returns>true if the string is null or empty</returns>
        private static bool IsStringNullOrEmpty(string stringToCheck)
        {
            return string.IsNullOrEmpty(stringToCheck) ||
                   string.IsNullOrEmpty(stringToCheck.Trim());
        }

        /// <summary>
        /// This is a generic method for testing to make sure a string is null 
        /// or empty. Empty is defined as have something besides space.
        /// </summary>
        /// <param name="stringToCheck">string to test</param>
        /// <param name="errorMessage">
        /// error message to put as the message for a 
        /// <see cref="System.ArgumentException"/>
        /// </param>
        /// <param name="throwException">set to true to throw an exception</param>
        /// <returns>true if the string is null or empty</returns>
        /// <exception cref="System.ArgumentException">
        /// If the error message is missing or throwException is true then an 
        /// ArgumentException will be thrown.
        /// </exception>
        public static bool IsStringNullOrEmpty(string stringToCheck,
                                               string errorMessage,
                                               bool throwException)
        {
            bool result;

            // Check if errorMessage argument is bad
            if ((throwException) && (IsStringNullOrEmpty(errorMessage)))
            {
                throw new ArgumentException("ErrorMessage cannot be empty.");
            }

            result = IsStringNullOrEmpty(stringToCheck);

            // If empty string and throw exception is true then create and 
            // throw exception
            if (result && throwException)
            {
                throw new ArgumentException(errorMessage);
            }

            return result;
        }

        public static void CaptureScreenShot(int x, int y, int width, int height, 
            Graphics sourceGraphicsObject, string fileName, System.Drawing.Imaging.ImageFormat imageFormat)
        {
            //Raster operation code for Copy from Source for BitBlt
            const int SRCCOPY = 0x00CC0020;

            //destination image and device context
            Bitmap memImage = new Bitmap(width, height);
            Graphics memGraphic = Graphics.FromImage(memImage);

            //get the Handles
            IntPtr destinationHdc = memGraphic.GetHdc();
            IntPtr sourceHdc = sourceGraphicsObject.GetHdc();

            //call the native function to grab the region 
            Native.BitBlt(destinationHdc, 0, 0, width, height, sourceHdc, x, y, SRCCOPY);

            //release
            sourceGraphicsObject.ReleaseHdc(sourceHdc);
            memGraphic.ReleaseHdc(destinationHdc);

            memImage.Save(fileName, imageFormat);

        }

        public static string GetDBConnectionString()
        {
            string connectionString = GlobalCache.Instance.AppPath + GlobalCache.Instance.SqlCeDatabase;

            return connectionString;
        }

    }
}