If you are asking yourself:
– How do I open this file with its default program without knowing where that program is installed?
– How do I launch common system actions through a simple interface without writing complex, low-level OS-specific code?
– How do I perform basic file operations with minimal code?
There is a solution you can use – it is called ShellExecute.
What is ShellExecute?
ShellExecute is a Windows API function used to perform various operations related to file manipulation or system interactions by launching or executing a specified file or operation associated with the default action for the specified file or application.
This function allows users to open files, folders, and URLs, and perform various actions associated with them, such as open, edit, print, explore, etc., from app’s menu, depending on the specified guidelines. In Delphi, it is used similarly to how it’s used in other programming languages for Windows.
It is a versatile function that serves several purposes:
- Launching Applications: It can be used to start any applications. For example, you can use it to open Notepad, launch a web browser, or execute any executable file.
- Opening Files: It can open files using the default program associated with their file types. For instance, it can open text files, documents, images, videos, etc., using their default associated applications.
- Performing Actions on Files: It allows performing various actions associated with files, such as editing, printing, and exploring (opening a folder to view its contents), among others.
- Handling URLs: It can open URLs in the default web browser. For instance, it can open a specific website link using the default web browser.
Developers use this function in Windows programming to initiate these kinds of operations and interactions within their applications. It relies on the default associations set up in the Windows Shell interface, allowing applications to leverage the default applications and behaviors set by the user for different file types and protocols.
Its flexibility makes it a widely used function in programming scenarios where there is a need to trigger various file-related operations or launch applications associated with specific file types or URLs.
How to use ShellExecute: Guide
Our team has rich expertise in Delphi development services which allowed us to accumulate a lot of valuable insights related to this technology. So, to use this function in Delphi, follow these steps:
- Include ShellAPI unit: Ensure that the ShellAPI (or Winapi.ShellAPI in current versions of Delphi) unit is included in your uses clause.
| 123 | uses
Winapi.ShellAPI; |
- Call ShellExecute function: In Delphi, it can be called with the appropriate parameters to perform the desired action.
Here’s an example demonstrating how to use this function to open a text file:
| 1234567 | procedure TForm1.Button1Click(Sender: TObject);
var
FilePath: string;
begin
FilePath := 'C:\Path\To\Your\File.txt';
ShellExecute(0, 'open', PChar(FilePath), nil, nil, SW_SHOWNORMAL);
end; |
This code uses these to open the file located at ‘C:\Path\To\Your\File.txt’ using the default program associated with text files in the system (‘open’ operation). You can change the operation or file path according to your specific use case.
The parameters for ShellExecute in Delphi are:
- hWnd: Handle to the window that will own the newly created window, or 0 if no window is to be created.
- Operation: The operation to perform (‘open’, ‘explore’, ‘print’, etc.).
- FileName: The name of the file or object on which to execute the specified operation.
- Parameters: Parameters to be passed to the application specified by FileName.
- Directory: The default directory for the application.
- ShowCmd: Flags that specify how an application window is to be displayed.
Adjust the parameters according to your specific requirements and desired action. In Delphi, ShellExecute parameters could include opening files, launching applications, opening URLs, and more.
Additional examples
Here is one more example for developers:
| 12345678910111213141516 | uses
ShellAPI;
procedure TForm1.Button1Click(Sender: TObject);
var
URL: string;
begin
URL := 'https://www.softacom.com/';
ShellExecute(0, 'open', PChar(URL), nil, nil, SW_SHOWNORMAL);
end;
procedure TForm1.Button2Click(Sender: TObject);
var
FileName: string;
begin
FileName := 'C:\Users\User\file.txt';
ShellExecute(0, 'print', PChar(FileName), nil, nil, SW_SHOWNORMAL);
end; |
Explanation of the ShellExecute parameters:
- hWnd: Handle to the window that will own the newly created window. Set to 0 to indicate no window association.
- Operation: The operation to perform, such as ‘open’, ‘edit’, ‘print’, etc.
- FileName: The file or object on which to execute the specified operation.
- Parameters: Additional parameters passed to the application (can be nil if not needed).
- Directory: The default directory for the application.
- ShowCmd: Specifies how the window is to be displayed (e.g., SW_SHOWNORMAL, SW_HIDE, etc.).
Ensure you include the ShellAPI unit in your uses clause to access the ShellExecute function.
