Three implementation methods of C ＃ client program calling external program

This article mainly introduces about C# The client program calls the... Of the external program 3 There are ways to do it , In this paper, the example code is introduced in detail , It has certain reference learning value for everyone's study or work .

brief introduction

Everybody knows , When we use C# To develop client programs , It's inevitable to call external programs or visit websites , This paper introduces three methods of calling external applications , For reference , I don't want to say much next , Let's have a look at the detailed introduction .

Realization

The first is to use shell32.dll, Realization ShellExecute Method , This method can open the local program at the same time 、 Folder or visit website , Just enter the path string directly , Such as C:\Users\Desktop\xx.exe perhaps https://cn.bing.com/, You can judge whether the call is successful according to the return value ( success 0x00000002a , Failure 0x00000002)

Window wnd = Window.GetWindow(this); // Get the current window var wih = new WindowInteropHelper(wnd); // This kind of support obtains hWndIntPtr hWnd = wih.Handle;    // Get window handle var result = ShellExecute(hWnd, "open", " The path that needs to be opened, such as C:\Users\Desktop\xx.exe", null, null, (int)ShowWindowCommands.SW_SHOW);​​​​​​​

[DllImport("shell32.dll")]public static extern IntPtr ShellExecute(IntPtr hwnd, // Window handle  string lpOperation, // Specify the operation to be performed  string lpFile,  // The program to be executed 、 Folder or web address to browse  string lpParameters, // if lpFile Parameter is an executable program , This parameter specifies the command line parameter  string lpDirectory, // Specify the default directory  int nShowCmd   // if lpFile Parameter is an executable program , This parameter specifies the initial display mode of the program window ( Refer to the following enumeration ) );​​​​​​​

public enum ShowWindowCommands : int{
    SW_HIDE = 0, SW_SHOWNORMAL = 1, SW_NORMAL = 1, SW_SHOWMINIMIZED = 2, SW_SHOWMAXIMIZED = 3, SW_MAXIMIZE = 3, SW_SHOWNOACTIVATE = 4, SW_SHOW = 5,  // Show a window , At the same time, make it active  SW_MINIMIZE = 6, SW_SHOWMINNOACTIVE = 7, SW_SHOWNA = 8, SW_RESTORE = 9, SW_SHOWDEFAULT = 10, SW_MAX = 10}

The second is to use kernel32.dll, Realization WinExec Method , This method can only open local programs , You can judge whether the call is successful according to the return value （<32 Indicates an error occurred ）

var result = WinExec(pathStr, (int)ShowWindowCommands.SW_SHOW);

[DllImport("kernel32.dll")]public static extern int WinExec(string programPath, int operType);

The third way is to use Process class ,Process The specific application of class can be seen from the definition of class , Here we only realize the usage of opening files and accessing websites , If the call fails, an exception will be thrown ​​​​​​

/// <devdoc>/// <para>///  Provides access to local and remote///  processes. Enables you to start and stop system processes./// </para>/// </devdoc>

The concrete realization is // Calling procedure

 Process process = new Process();try {
     process.StartInfo.UseShellExecute = false;  process.StartInfo.FileName = pathStr;  process.StartInfo.CreateNoWindow = true;  process.Start(); }  catch (Exception ex) {
     MessageBox.Show(ex.Message); }// Visit website try{
     Process.Start("iexplore.exe", pathStr);}  catch (Exception ex){
     MessageBox.Show(ex.Message);}