Question

I have a windows form application. On the form there are three groupboxs.
Each groupbox contains some controls. Please see the image.

There is a groupbox “flag” that contains a few checkboxs. “flag” is inside in “groupbox1”.
I used Tab key to go through each control but it doesn’t work for checkboxs in “flag”. I did set proper tabindex for each control.

It works for textboxs and buttons but checkboxs.

Why? Thanks for help.

EDIT

 // groupBox2
        // 
        this.groupBox2.Controls.Add(this.pictureBox10);
        this.groupBox2.Controls.Add(this.pictureBox9);
        this.groupBox2.Controls.Add(this.pictureBox8);
        this.groupBox2.Controls.Add(this.pictureBox7);
        this.groupBox2.Controls.Add(this.chkStoplight);
        this.groupBox2.Controls.Add(this.lblStoplight);
        this.groupBox2.Controls.Add(this.chkIsCount);
        this.groupBox2.Controls.Add(this.chkExceptionFlag);
        this.groupBox2.Controls.Add(this.chkIsActive);
        this.groupBox2.Controls.Add(this.lblIsActive);
        this.groupBox2.Controls.Add(this.lblExceptionFlag);
        this.groupBox3.Controls.Add(this.lblIsCount);
        this.groupBox2.Location = new System.Drawing.Point(16, 201);
        this.groupBox2.Name = "groupBox2";
        this.groupBox2.Size = new System.Drawing.Size(321, 70);
        this.groupBox2.TabIndex = 10;
        this.groupBox2.TabStop = true;
        this.groupBox2.Text = "Flags";

        // 
        // chkStoplight
        // 
        this.chkStoplight.AutoSize = true;
        this.chkStoplight.Location = new System.Drawing.Point(44, 25);
        this.chkStoplight.Name = "chkStoplight";
        this.chkStoplight.Size = new System.Drawing.Size(15, 14);
        this.chkStoplight.TabIndex = 0;
        this.chkStoplight.UseVisualStyleBackColor = true;

        In the property, I found TabStop is true for chkStoplight.

Answer 1

For System.Windows.Forms.GroupBox:

You should make sure that your GroupBox flag has an appropriate TabIndex set.

From MSDN – How to: Set the Tab Order on Windows Forms:

Additionally, by default, a GroupBox control has its own TabIndex
value, which is a whole number. A GroupBox control itself cannot have
focus at run time. Thus, each control within a GroupBox has its own
decimal TabIndex value, beginning with .0. Naturally, as the TabIndex
of a GroupBox control is incremented, the controls within it will be
incremented accordingly. If you changed a TabIndex value from 5 to 6,
the TabIndex value of the first control in its group automatically
changes to 6.0, and so on

Also, make sure the TabStop property of your GroupBox flag is not set to false. I believe false is the default.

For System.Windows.Controls GroupBox:

Make sure that the GroupBox.IsTabStop property is set. This also defaults to false.

Update: It appears that all of your controls are being added to groupBox3. You should make sure that each of them is being added only to its containing groupbox. For example, checkBox1, checkBox2, and checkBox3 should all be added to flag, which itself should be added to groupBox1. groupBox3 should only contain Back, Next, Finish, and Cancel.