像属性一样的方法中变量的专有名称是什么？

Question

I know this is a stupid question, but I have been teaching myself c#, so im learning the lingo as I go.

My question is: Often when I write methods, I find my self declaring objects and variables at the top of the method when I need them to share the same scope. Do these types of objects/variables have a name? I know when declared outside a method they would be properties.

Example code of what I mean: My question is what to call the objects in the Question region.

public Label start_Ping(String target, string name, ref bool router)
        {

       #region [ Question ] 
        Label status_Label = new Label(); //Declare the label which will be dynamically      created 

        Ping ping = new System.Net.NetworkInformation.Ping(); //Declare the ping object 

        PingReply reply = null; //Declare the pingReply object      


        byte[] buffer = new byte[100]; //Set the byte size 
       #endregion 

        if (name == "router")
        {
            try
            {
                reply = ping.Send(target, 50, buffer);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
            if (reply.Status == IPStatus.Success)
            {
                router = true;
            }
            else
            {
                router = false;
                return null;
            }
        }
try
{
...

Thanks in advance. I understand this may be quite simple =)

Answer 1

In your code, status_Label , ping , reply and buffer are known simply as local variables .

That is, they're local to the method you create them in (or whatever scope you declare them in).

It doesn't matter where in your method you declare them, by the way, as long as they're within some scope.

Answer 2

BoltClock is correct, but for future reference, variables declared outside of a method aren't properties. They're called member variables. Properties are different.

For example:

public class ExampleClass {
    String myString = "Hello World!";

    public String MyProperty {
        get { return myString; }
        set {
            myString = value;
            System.Console.WriteLine("MyProperty changed to " + value);
        }
    }
}

Here, myString is a member variable (or instance variable). It can't be accessed from outside the class.

MyProperty, as the name suggests, is a property. It's actually a kind of method that behaves like a variable, but allows other things to happen when its value is changed or accessed. In this example, setting MyProperty would output a message giving its new value.

There's some good documentation on this at MSDN here and here .

Hope this helps.

Answer 3

@BoltClock has answered your question; however, I wanted to point out that your statement, “when [variables are] declared outside a method they would be properties”, is incorrect. Variables declared outside a method are called fields . Properties typically have a similar purpose to fields (holding a value), but they need to be defined using get and set accessors, and can incorporate logic, such as validation or property change notification (which fields can't).

For example:

public class Router
{
    private PingReply reply = null;

    public PingReply Reply
    {
        get { return reply; }
        set { reply = value; }
    }
}

In this case, reply is a field, whilst Reply is a property which gets or sets the value of reply .