GDI+ Cursors

Introduction

A cursor is a small picture that represents the position of the mouse on a Windows screen. Because Microsoft Windows is a graphic-oriented operating system, when it installs, it creates a set of standard or regularly used icons. These can be seen by opening the Control Panel window and double-clicking the Mouse icon. This opens the Mouse Properties dialog box where you can click the Pointers tab to see a list of standard cursors installed by Windows:

Microsoft Visual Studio 2005 provides a rich collections of cursors you can easily use in your application. You can apply them to any control as you wish. To do this, access the properties of the control and open the Cursor field. If those cursors are not enough, which is not unusual, you can use your own cursors..

1. Start a new Windows Forms Application named Resources2
2. Change the Text property of the form to GDI+ Resources
3. On the Toolbox, click the ListBox control and click the upper-left section of the form
4. Again, on the Toolbox, click the Panel control and click the upper-right section of the form
5. Once again, on the Toolbox, click the TreeView control and click the lower-left section of the form
6. On the Toolbox, click the RichTextBox control and click the upper-right section of the form
    
   

To create and design your own cursor, you can use use Microsoft Visual Studio. To do this:

• In the Solution Explorer, you can right- click Resource Files -> Add -> Resource...
• In the Resource View, you can right-click the name of the project -> Add -> Resource

Then, in the Add New Item dialog box, you can select Cursor File, give it a name and click Open.

A cursor is a Windows file that has the extension .cur.

1. Display the Resource View window.
   To create a new cursor, in the Resource View, right-click Resources2 -> Add -> Resource...
2. In the Add Resource dialog box, click Cursor and click New
3. In the Resource View tab, click the new IDC_CURSOR1
4. In the Properties window, change the Filename to Push.cur and change the ID to IDC_PUSH
5. On the Image Editor toolbar, click the Line tool . In the Colors window, make sure the black color is selected
6. Draw a vertical line from the pixel on the 6th column and 2nd row from top
7. Draw a diagonal line at 45˚ from the top border of the new line to the lower-right until the line is at 5 pixels from the right border of the drawing area
    
   
8. Draw a horizontal line from the lower border of the dialog line to half-left
9. Draw a diagonal line from the lower border of the vertical line to the left border of the horizontal line:
    
   
10. Draw another diagonal line from the top corner of the current shape to the intersection of horizontal and left diagonal line:
     
    
11. On the Image Editor toolbar, click Fill
12. In the Colors window, click the button with a pink monitor
13. In the drawing area, click the right triangle.
14. In the Colors window, click the white color
15. On the drawing area, click in the left triangle
     
    
16. To set the position of the cursor pointer, on the Image Editor toolbar, click the Set Hot Spot Tool
17. Click the tip of the cursor at the intersection of vertical and the the diagonal lines in the top-left section
     
    
18. Save the icon

There are two main ways you can use a cursor in your application. The easiest cursors are listed in the Cursor field of the Properties window for the control whose cursor you want to change. The available cursors are:

You can select one of these cursors in the Properties window and assign it to a control. These cursors are defined in a class called Cursors. This simple class mostly contains only a list of available cursors as properties. All these cursors are represented as static properties. Therefore, to use one of these cursors, call the name of the class, Cursors, followed by the class access operator "::", followed by the name of the cursor as it appears in the above list.

Another technique consists of using a cursor not listed in the Properties window. A cursor is based on the Cursor class. Both the Cursors and the Cursor classes are defined in the System::Windows::Forms namespace that is part of the System.Windows.Forms.dll library.

The Cursor class provides four constructors. One of them allows you to specify the path where the cursor is located. This constructor has the following syntax:

public:
    Cursor(String ^ filename);

The argument passed to this constructor is the name or the location of the cursor as a file. After calling this constructor to initialize a Cursor variable, the cursor is ready. You can then use it as you see fit. For example, you can assign it to the Cursor property of a control.

When the cursor of a control has been changed, the control fires a CursorChanged event. This event is of type EventArgs.

If at any time you want to hide a cursor, you can call the Cursor::Hide() method. Its syntax is:

public:
    static void Hide();

To display the cursor again, you can call the Cursor::Show() method. Its syntax is:

public:
    static void Show();

1. Display the form. Click the control on the upper-left section of the form
2. In the Properties window, click the arrow of the combo box of the Cursor field and select PanNorth
3. Double-click an unoccupied area of the form to access its Load event
4. To programmatically assign cursors, implement the event as follows:
    

   System::Void Form1_Load(System::Object^ sender, System::EventArgs^ e) { System::Windows::Forms::Cursor ^ curPush = gcnew System::Windows::Forms::Cursor(L"Push.cur"); this->panel1->Cursor = Cursors::NoMove2D; this->treeView1->Cursor = curPush; this->richTextBox1->Cursor = Cursors::PanSE; }

5. Execute the application to test it
    
6. Close the form and return to your programming environment