Disable and enable buttons in C#

Question

I am working on something fairly simple, well I thought it would be. What I want is when button1 is clicked I want it to disable button1 and enable button2. I get the error below: Error 1 Only assignment, call, increment, decrement, and new object expressions can be used as a statement.

private readonly Process proc = new Process();
    public Form1()
    {
        InitializeComponent();
        button2.Enabled = false;
    }

    private void button1_Click(object sender, EventArgs e)
    {
        proc.StartInfo = new ProcessStartInfo {
            FileName = Environment.GetFolderPath(Environment.SpecialFolder.Windows) + "/explorer.exe",
            Arguments = @"D:\",
            UseShellExecute = false
        };
        proc.Start();
        button1.Enabled = false;
        button2.Enabled = true;
    }


    private void button2_Click(object sender, EventArgs e)
    {
        proc.Kill();
        button1.Enabled = true;
        button2.Enabled = false;
    }

Let's see how many people ignore reading the current correct answers and post the exact same answer.... ready ... go. — Gabe, Nov 05 '10 at 16:40
Please note that your code has an issue with `Random`, see http://stackoverflow.com/questions/1654887/random-next-returns-always-the-same-values — Dirk Vollmar, Nov 05 '10 at 16:49
@gmcalab: The answers so far all were written at the same time basically. — Dirk Vollmar, Nov 05 '10 at 16:57
https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/inside-a-program/coding-conventions "=" assign value to a variable "==" compares variable — ger, Dec 07 '18 at 13:55

thattolleyguy · Accepted Answer · 2010-11-05T16:55:47.127

33

In your button1_click function you are using '==' for button2.Enabled == true;

This should be button2.Enabled = true;

edited Nov 05 '10 at 16:55

answered Nov 05 '10 at 16:37

thattolleyguy

765
5
11

score 12 · Answer 2 · answered Nov 05 '10 at 16:36

12

button2.Enabled == true ; must be button2.Enabled = true ;.

You have a compare == where you should have an assign =.

answered Nov 05 '10 at 16:36

Pieter van Ginkel

28,744
8
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score 5 · Answer 3 · answered Nov 05 '10 at 16:36

5

button2.Enabled == true ;

thats the problem - it should be:

button2.Enabled = true ;

answered Nov 05 '10 at 16:36

stack72

8,050
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It would be nice if the code view automatically had line-numbering applied. It took too long to visually find that. – FrustratedWithFormsDesigner Nov 05 '10 at 16:38

score 5 · Answer 4 · edited Jul 23 '12 at 12:33

5

Change this

button2.Enabled == true

to

button2.Enabled = true;

edited Jul 23 '12 at 12:33

Tisho

7,870
6
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answered Nov 05 '10 at 16:36

123 456 789 0

10,482
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score 4 · Answer 5 · answered Nov 05 '10 at 16:36

4

button2.Enabled == true ;

should be

button2.Enabled = true ;

answered Nov 05 '10 at 16:36

Gabriel Magana

4,209
23
22

score 3 · Answer 6 · answered Nov 05 '10 at 16:37

3

It is this line button2.Enabled == true, it should be button2.Enabled = true. You are doing comparison when you should be doing assignment.

answered Nov 05 '10 at 16:37

Alex McBride

6,771
3
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score 1 · Answer 7 · answered Jun 03 '19 at 15:55

1

Update 2019

This is now IsEnabled

 takePicturebutton.IsEnabled = false; // true

answered Jun 03 '19 at 15:55

Java.Her

77
6

score 0 · Answer 8 · edited Oct 10 '12 at 19:57

You can use this for your purpose.

In parent form:

private void addCustomerToolStripMenuItem_Click(object sender, EventArgs e)
{
    CustomerPage f = new CustomerPage();
    f.LoadType = 1;
    f.MdiParent = this;
    f.Show();            
    f.Focus();
}

In child form:

public int LoadType{get;set;}

private void CustomerPage_Load(object sender, EventArgs e)
{        
    if (LoadType == 1)
    {
        this.button1.Visible = false;
    }
}

Disable and enable buttons in C#

8 Answers8

Update 2019