How to resize height of ListView to fit content

Question

Hey all I have been looking around the ol' net for a soluction that would allow me to resize my listview depending on the last entry in it.

So far I have only turned out how to do this using other controls like Telerik and Syncfusion , etc... Besides those companies I only find ways to just size up the row or column depending on the content inside it - not the overall height of the listview itself. Other examples also are close to what I am looking to want to do but are for WPF .

My winform looks like this right now:

But what I am wanting it to do is this:

Has anyone done this before that could show the code they used? Or is there a better control I could be using for my needs that would do what I am needing? Thanks!

Answer 1

Sending a LVM_APPROXIMATEVIEWRECT message to Control, you can get back an approximate measure that includes the Header's height and the size of all the Items.
Setting the ClientSize of the Control to this measure, should allow to resize the ListView, to show all Items in their full extent.

You can specify a number of Items to include ( wParam ) and a preferred size ( lParam ), or set both lParam and wParam to -1 : in this case, all Items are included and the size is auto-detected.

Note that the height may include the horizontal Scrollbar height: a margin may be visible at the bottom.
If that's not desirable, remove SystemInformation.HorizontalScrollBarHeight from the overall height.

Or do the same thing to limit the extent of the Control to a specific measure, if the number of Items in the ListView suggests it.

► As noted in comments, if the ListView is docked to the Form, setting its ClientSize doesn't have any visible effect.
In this case, you need to also resize the Form, adding the difference between the old Size of the ListView and its new calculated size.

Assuming the ListView is named listView1 :

Size oldSize = listView1.ClientSize;
int hScrollBarHeight = SystemInformation.HorizontalScrollBarHeight

// Both wParam and lParam set to -1: include all Items and full size
int approxSize = NativeMethods.SendMessage(
    listView1.Handle, NativeMethods.LVM_APPROXIMATEVIEWRECT, -1, (-1 << 16 | -1));
int approxHeight = approxSize >> 16;
int approxWidth = approxSize & 0xFFFF;

Size newSize = new Size(approxWidth, approxHeight - hScrollBarHeight);

// If needed, resize the Form (here, grow and shrink) to adapt to the new size
// Checking the Dock property state is a possible example, apply whatever logic fits
if (listView1.Dock != DockStyle.None) {
    this.Height += newSize.Height - oldSize.Height;
    this.Width += newSize.Width - oldSize.Width;
}

listView1.ClientSize = newSize;

internal class NativeMethods 
{
    internal const int LVM_FIRST = 0x1000;
    internal const int LVM_APPROXIMATEVIEWRECT = LVM_FIRST + 0x40;

    [DllImport("user32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    internal static extern int SendMessage(IntPtr hWnd, int uMsg, int wParam, int lParam);
}