如何声明可以在其他事件中使用的对象？

Question

I am working on a windows form. I am creating an object called client and the client has many functions including login() search(). the login function is called when I click the "login button" and the search function is called when I click on the "search button"

I was able to accomplish to create a "global object"( for a lack of a better term) by declaring it here:

namespace WindowsFormsApplication1
{

public partial class Form1 : Form
{
    MyClient client = new MyClient();

 private void btnLogIn_Click(object sender, EventArgs e)
    {
       client.login()
 private void btnSearch_Click(object sender, EventArgs e)
    {
       client.search()

Now, the problem I face is that sometimes the client disconnects and I have to use another object to relogin, I cannot use the same object.

I am thinking about having a button to relogin, create a new object, and keep using the same name "client" for the object on the other events.

Any thoughts?

Answer 1

You can wrap your client variable in a property or method, which encapsulates logic to determine if you need to reconnect. Suppose you had a method in client called wasDisconnected() which does this. You could "lazy-load" the class-level variable like such.

public partial class Form1
{
    MyClient _client;

    protected MyClient client
    {
        get
        {
            // Check if we need to reconnect.
            if (_client == null || client.wasDisconnected())
                _client = new MyClient();
            return _client;
        }
    }

    // ...
}

Your click methods in this case would remain unchanged, but they would now access the MyClient instance through the property instead of directly.