如何修复在TableLayoutPanel上显示的滚动条？

Question

Got a TableLayoutPanel in my winform, to increase loading speed. I tried suspending it's layout, adding the rows and resume Layout. Sadly if I suspend until all rows are added, I get a horizontal scroll bar that does not appear if I resume Layout inbefore adding or suspend after adding each row again.

Msdn states "Add method reapplies the table layout to all the controls" :

That's what I have to reproduce by my own code after all rows are added. However adding another row in the end does not produce the layout not suspending at all does.

I tried:

• replace the first column's content with new Control() just to test if the content was too large.
• change the contents size -> led to smaller content, more whitespace and same problem
• change the tableLayoutPanel's size -> led to a smaller control with still the same problem
• change the first column's size (as the later two ones have absolute values) from 100% to a lower percent value, autosize and a similar absolute value -> led to the last column begin oversized, still visible scrollbar
• PerformLayout() after rows are added
• Refresh() after rows are added
• ResumeLayout(true) to force pending layout requests/changes (Should absolutely give me the layout I want and get without suspending, maybe buggy or something is overwritten?)
• Update() after rows are added

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tl;dr add rows, lag, no scrollbar vs suspend, add rows, horizontal scrollbar

why and how not to?

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Found out that without all the suspending and resuming I experience the same problem if I add EXACTLY 5 rows: 4 work fine as no scrollbar is needed, 6 remove the horizontal scrollbar, 5 is buggy. So the problem goes deeper than layout suspending. There is definitely something wrong with adding a specifing amount of rows overall. -> outsourced to new question (required for this one) -> solved outsourced question ,

paused until I stumble upon problems with Suspending again

Answer 1

This question is linked with a problem I outsourced and solved here , consider the code over there as the main solution, this is a small addition.

As described in the question's comments, there is a specific amount of rows I've to add without suspending (related to the height of the TableLayoutPanel ), this seems to work in most cases ( inp.Count is the amount of rows added) :

tableLayoutPanel1.SuspendLayout();
int i;
while ((i = tableLayoutPanel1.Controls.Count) >= 2) {
    tableLayoutPanel1.Controls[--i].Dispose();
    tableLayoutPanel1.Controls[--i].Dispose();
    tableLayoutPanel1.Controls[--i].Dispose();
}
while (tableLayoutPanel1.RowStyles.Count > 0) {
        tableLayoutPanel1.RowStyles.RemoveAt(tableLayoutPanel1.RowStyles.Count - 1);
}
tableLayoutPanel1.RowCount = 0;
for(int i=0; i<inp.Count; i++){
    if (i > inp.Count - 6) {
        tableLayoutPanel1.ResumeLayout();
    }
//...
}

Check the above linked solution for that one case where inp.Count is not big enough to fix the horizontal scrollbar.

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This improves the loading time massively, however there is still lag of visual elements, why I decided to add in tableLayoutPanel1.Hide(); at the beginning and tableLayoutPanel1.Show(); at the end.

Even hiding the parent control doesn't prevent the user from seeing how the rows disappear, also after revealing the control again, the table borders are shown first before the content itself is loaded. So this solution isn't perfect, but the extent it works to shall be enough here.