C#

how are you all.
i am new to asp.net and c#. i need help.

well my question is, i have a textbox in which a user have to enter a float value in the webform.

and i want to manipulate that value in a calculation.
so have created a class for the calculation which is Sales class. in that class i have declared Price as a float value,the value which should be obtained from the textbox.ie public float Price {get;set;}

Now my problem is with binding/linking the Price variable with the textbox in the button_click method.

initially i had done it this way:

in my .aspx.cs file i have created an object of the class in this case :

Sales s = new Sales ();

protected void button_Click (object sender EventArgs e)

{
s.Price =Convert.ToInt32(Textbox1.Text);
s.Save();
}

i want the Price value to be saved in my database after a user clicks the SAVE button from the webform.

Now the problem is when i run the application there is an error (
Hide   Copy Code

An exception of type 'System.FormatException occur but was not handred in the mscorlib.dll but was not handled in the  user code

)
on the line :
s.Price = Convert.ToInt32(Textbox1.Text);

could i have done something wrong in the code?

how are you all.
i am new to asp.net and c#. i need help.

well my question is, i have a textbox in which a user have to enter a float value in the webform.

and i want to manipulate that value in a calculation.
so have created a class for the calculation which is Sales class. in that class i have declared Price as a float value,the value which should be obtained from the textbox.ie public float Price {get;set;}

Now my problem is with binding/linking the Price variable with the textbox in the button_click method.

initially i had done it this way:

in my .aspx.cs file i have created an object of the class in this case :

Sales s = new Sales ();

protected void button_Click (object sender EventArgs e)

{
s.Price =Convert.ToInt32(Textbox1.Text);
s.Save();
}

i want the Price value to be saved in my database after a user clicks the SAVE button from the webform.

Now the problem is when i run the application there is an error (
Hide   Copy Code

An exception of type 'System.NullReferenceException' occurred in Version1.dll but was not handled in user code

)
on the line :
s.Price = Convert.ToInt32(Textbox1.Text);

could i have done something wrong in the code?

how are you all.
i am new to asp.net and c#. i need help.

well my question is, i have a textbox in which a user have to enter a float value in the webform.

and i want to manipulate that value in a calculation.
so have created a class for the calculation which is Sales class. in that class i have declared Price as a float value,the value which should be obtained from the textbox.ie public float Price {get;set;}

Now my problem is with binding/linking the Price variable with the textbox in the button_click method.

initially i had done it this way:

in my .aspx.cs file i have created an object of the class in this case :

Sales s = new Sales ();

protected void button_Click (object sender EventArgs e)

{
s.Price =Convert.ToInt32(Textbox1.Text);
s.Save();
}

i want the Price value to be saved in my database after a user clicks the SAVE button from the webform.

Now the problem is when i run the application there is an error (
Hide   Copy Code

An exception of type 'System.NullReferenceException' occurred in Version1.dll but was not handled in user code

)
on the line :
s.Price = Convert.ToInt32(Textbox1.Text);

could i have done something wrong in the code?

private void PrintSomething()
{
   //some code here
}

MethodInvoker mi = new MethodInvoker(PrintSomething);
mi.BeginInvoke(null, null);

private void btn_click(object sender, EventArgs e)
{
   PrintSomething();
}

using (OdbcConnection connexion_source = new OdbcConnection(con_source))
            using (OdbcCommand command_source = connexion_source.CreateCommand())
               {
                   command_source.CommandText = "select max(date) from thisdet;";
                   OdbcDataAdapter MyAdapter = new OdbcDataAdapter(command_source);
                   MyAdapter.Fill(dt_source);
               }

public static IObservable<EventPattern<PropertyChangedEventArgs>> ObservePropertyChanged(this INotifyPropertyChanged collection, string PropertyName)
{
    return Observable.FromEventPattern<PropertyChangedEventHandler, PropertyChangedEventArgs>(
            handler => (sender, e) => handler(sender, e),
            handler => collection.PropertyChanged += handler,
            handler => collection.PropertyChanged -= handler)
            .Where(evt => evt.EventArgs.PropertyName == PropertyName);
}

public static IDisposable SubscribeWeakly<T, TTarget>(this IObservable<T> observable, TTarget target, Action<TTarget, T> onNext) where TTarget : class
{
    var reference = new WeakReference(target);

    //if (onNext.Target != null)
    //{
    ////    throw new ArgumentException("onNext must refer to a static method, or else the subscription will still hold a strong reference to target");
    //}

    IDisposable subscription = null;
    subscription = observable.Subscribe(item =>
    {
        var currentTarget = reference.Target as TTarget;
        if (currentTarget != null)
        {
            onNext(currentTarget, item);
        }
        else
        {
            subscription.Dispose();
        }
    });

    return subscription;
}

Expression<Func<int, int, string>> expression = (a, b) => "soemthing";