CODEWITHSUNDEEP
c#winforms
Arie
Arie

Reputation: 5373

Strange Label AutoSize issue on TableLayoutPanel resize

Background:

I have a TableLayoutPanel placed in a UserControl, which then is placed in SplitContainer. Rows are added programmatically. TableLayoutPanel is anchored Top|Left|Right, so after rows are added, its height is recalculated and it expands downward.

Inside the TableLayoutPanel, there are two columns. The size of the first column is Absolute, the size of the second column is set to AutoSize.

In every cell, there is a Label. All labels in the second column are defined as follows:

  Label vName = new Label();
  vName.AutoSize = true;
  vName.Anchor = AnchorStyles.Left | AnchorStyles.Top | AnchorStyles.Right | AnchorStyles.Bottom;
  vName.Margin = new Padding(3);
  vName.TextAlign = ContentAlignment.MiddleLeft;
  vName.Name = "controlName";
  vName.Text = "Some text here";
  vName.DoubleClick += new EventHandler(vName_DoubleClick);
  vName.Dock = DockStyle.None;

The problem:

Usually, everything works all right, labels resize and everything, except for one strange scenario:

  1. The text of the label is something like "immoballizes the device (33.33%)", width of TableLauoutPanel's second column is set exactly, so all text is shown in one line.
  2. Splitter distance changes by one pixel and the UserControl is resized: width decreases, so the label should resize, and the text in a label should wrap.
  3. The label is not resized, and the second line of text isn't shown, it also probably doesn't wrap (there would be a change in the text location in the label if it did).
  4. Splitter distance changes by one pixel again, and the UserControl is resized: the width decreases further.
  5. The label resizes all right and all text is shown, wrapped.

The same thing happens when the TableLayoutPanel's width increases, but always only if there is a difference of one pixel (between wrapping/not wrapping text).

Also, changing Dock and/or Anchor and/or BorderStyle properties of labels doesn't work (I probably tried all possible combinations...)

This picture illustrates the issue a little:

enter image description here

Upvotes: 1

Views: 3397

Answers (1)

Arie
Arie

Reputation: 5373

Apparently it is a label issue: when autosizing, it wasn't measuring text correctly and sometimes there was a one pixel difference. I've found a strange workaround, though, if someone knows something better please enlighten me.

This way text in my labels wraps correctly every time and everything is autosized properly:

void tableLayoutPanel1_Resize(object sender, EventArgs e)
        {
            float fWidth = tableLayoutPanel1.GetColumnWidths()[1];
            foreach (Control ctr in tableLayoutPanel1.Controls)
            {
                if (ctr is Label && ctr.Name.Contains("vName_"))
                {
                    // -7 for margins
                    Size s = TextRenderer.MeasureText(ctr.Text, ctr.Font, new Size((int)fWidth - 7,1000),
                        TextFormatFlags.VerticalCenter 
                        | TextFormatFlags.Left 
                        | TextFormatFlags.NoPadding 
                        | TextFormatFlags.WordBreak);
                    if(!ctr.MaximumSize.Equals(s))
                        ctr.MaximumSize = new Size(s.Width, s.Height);
                }
            }
        }

Upvotes: 1

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