Stop button event WPF, Selenium

Question

How to stop button event when exception fired..?I used try catch blocks, if exception fired it will try to execute next code, i dont want that...pls check comments in code..M i using try catch blocks wrongly..?

here is my code:

private void Button_Click_1(object sender, RoutedEventArgs e)
{
    try
    {
         driver.FindElement(By.CssSelector(".username")).SendKeys("abc");
         driver.FindElement(By.CssSelector(".password")).SendKeys("abcpassword");
         driver.FindElement(By.XPath("//a[2]/img")).Click();
    }
    catch(Exception ex)
    {
        driver.Quit();
        MessegeBox.Show("Log in failed");
        //stop button event here only if exception fired
    }

    try
    {
        new SelectElement(driver.FindElement(By.Id("CId"))).SelectByText("CVB");
        driver.FindElement(By.Name("ddd")).Click();
    }
    catch(Exception ex)
    {   
        driver.Quit();
        MessegeBox.Show("Log in failed");
        //stop button event here only if exception fired
    }

    Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();
    Excel.Workbook xlWorkBook;
    Excel.Worksheet xlWorkSheet;
    xlApp.DisplayAlerts = false;
    object misValue = System.Reflection.Missing.Value;
}

Answer 1

The catch only breaks execution of code inside try block. It doesn't return from the method. Typical scenario is indeed just one try/catch block in the method (so that catch will be also the last in your method -> method will ends):

public void SomeMethod()
{
    try
    {
        ...
    }
    catch(...)
    {
        ...
    }
    ... // code will continue to run here, if no code left method will ends
}

In your case you have to exit method to avoid other try/catch to run, means use return keyword like this:

public void SomeMethod()
{
    try
    {
        ...
    }
    catch(...)
    {
        ...
        return;
    }
    ... // this code will not run in case of exception in try block
}

Answer 2

I would suggest that you restructure you code like below. Even better is to handle specific exceptions rather than handling the generic Exception.

    private void Button_Click_1(object sender, RoutedEventArgs e)
    {
        try
        {
            driver.FindElement(By.CssSelector(".username")).SendKeys("abc");
            driver.FindElement(By.CssSelector(".password")).SendKeys("abcpassword");
            driver.FindElement(By.XPath("//a[2]/img")).Click();

            new SelectElement(driver.FindElement(By.Id("CId"))).SelectByText("CVB");
            driver.FindElement(By.Name("ddd")).Click();
        }
        catch (Exception ex)
        {
            driver.Quit();
            MessegeBox.Show("Log in failed");
            return;
        }

        Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();
        Excel.Workbook xlWorkBook;
        Excel.Worksheet xlWorkSheet;
        xlApp.DisplayAlerts = false;
        object misValue = System.Reflection.Missing.Value;
    }