How to: Refactor Code with Extract Method
The following procedure describes how to create a new method from a code fragment of an existing member. Use this procedure to perform the Extract Method refactoring operation.
To use Extract Method
Create a console application.
For more information, see Creating Console Applications (Visual C#).
In the Code Editor, select the code fragment you want to extract:
double area = PI * radius * radius.On the Refactor menu, click Extract Method.
The Extract Method dialog box appears.
Alternatively, you can also type the keyboard shortcut CTRL+R, M to display the Extract Method dialog box.
You can also right-click the selected code, point to Refactor, and then click Extract Method to display the Extract Method dialog box.
Specify a name for the new method, such as CircleArea, in the New Method Name box.
A preview of the new method signature displays under Preview Method Signature.
Click OK.
Example
To set up this example, create a console application named ExtractMethod, and then replace Program with the following code. For more information, see Creating Console Applications (Visual C#).
class A
{
const double PI = 3.141592;
double CalculatePaintNeeded(double paintPerUnit, double radius)
{
// Select any of the following:
// 1. The entire next line of code.
// 2. The right-hand side of the next line of code.
// 3. Just "PI *" of the right-hand side of the next line
// of code (to see the prompt for selection expansion).
// 4. All code within the method body.
// ...Then invoke Extract Method.
double area = PI * radius * radius;
return area / paintPerUnit;
}
}