ListView的最后一列自动调整创建滚动条 [英] ListView Final Column Autosize creates scrollbar

问题描述

我在执行从ListView中派生的自定义控制。

I am implementing a custom control which derives from ListView.

我想对于最后一列，以填补剩余空间（一个相当普遍的任务），我已经通过重写onResize受到了方法这个：

I would like for the final column to fill the remaining space (Quite a common task), I have gone about this via overriding the OnResize method:

     protected override void OnResize(EventArgs e)
    {
        base.OnResize(e);

        if (Columns.Count == 0)
            return;
        Columns[Columns.Count - 1].Width = -2; // -2 = Fill remaining space
    }

或通过另一种方法：

        protected override void OnResize(EventArgs e)
    {

        base.OnResize(e);

        if (!_autoFillLastColumn)
            return;

        if (Columns.Count == 0)
            return;

        int TotalWidth = 0;
        int i = 0;
        for (; i < Columns.Count - 1; i++)
        {
            TotalWidth += Columns[i].Width;
        }

        Columns[i].Width = this.DisplayRectangle.Width - TotalWidth;
    }

编辑：

直到我停靠在ListView到父容器，并通过该控制调整这工作得很好。控制尺寸的缩小每一秒钟时间（即，拖动边框一个像素），我得到的底部有一个滚动条，可以不是在所有（甚至没有一个像素）移动。

This works fine until I dock the ListView into a parent container and resize via that control. Every second time the control size shrinks (IE, drag the the border one pixel), I get a scroll bar on the bottom which can't move at all (not even one pixel).

其结果是，当我拖累我留下ListView中一个闪烁的滚动条的父级的大小和50％的机会，它将在那里当拖拽停止。

The result of which is when I drag the size of the parent I am left with a flickering scroll bar in the ListView, and a 50% chance it will be there when the dragging stops.

推荐答案

ObjectListView （约.NET的WinForms ListView的一个开放源代码包装）允许这种扩大，最后一列来一补可用空间。它实际上更难获得正确的不是它第一次出现 - 不要相信任何人谁告诉你，否则：）

ObjectListView (an open source wrapper around .NET WinForms ListView) allows this "expand-last-column-to-fill-available-space". It's actually more difficult to get right than it first appears -- do not believe anyone who tells you otherwise :)

如果您使用ObjectListView，你得到的解决这一问题 - 和其他几个人 - 是免费的。但是，如果你想自己做所有的工作，你需要：

If you use ObjectListView, you get the solution to that problem -- and several others -- for free. But if you want to do all the work yourself, you'll need to:

• 使用ClientSize代替DisplayRectangle（如@zxpro已经表示）


• 使用布局事件，而不是Resize事件。


• 监听ColumnResized事件，做同样的工作


• 这样做在设计模式中自动调整大小 - 它变得非常混乱

只有当窗口缩小出现最棘手的问题 - 水平滚动条闪烁烦人，有时甚至萎缩完成后仍然存在。这似乎是到底是什么在您的情况发生。

The trickiest problem only appears when the window shrinks -- the horizontal scroll bar flickers annoyingly and sometimes remains after the shrinking is finished. Which appears to be exactly what is happening in your case.

解决的办法是截获WM_WINDOWPOSCHANGING消息并调整其大小的ListView什么新的大小将是。

The solution is to intercept the WM_WINDOWPOSCHANGING message and resize the ListView to what the new size is going to be.

protected override void WndProc(ref Message m) {
    switch (m.Msg) {
        case 0x46: // WM_WINDOWPOSCHANGING
            this.HandleWindowPosChanging(ref m);
            base.WndProc(ref m);
            break;
        default:
            base.WndProc(ref m);
            break;
    }
}

protected virtual void HandleWindowPosChanging(ref Message m) {
    const int SWP_NOSIZE = 1;

    NativeMethods.WINDOWPOS pos = (NativeMethods.WINDOWPOS)m.GetLParam(typeof(NativeMethods.WINDOWPOS));
    if ((pos.flags & SWP_NOSIZE) == 0) {
        if (pos.cx < this.Bounds.Width) // only when shrinking
            // pos.cx is the window width, not the client area width, so we have to subtract the border widths
            this.ResizeFreeSpaceFillingColumns(pos.cx - (this.Bounds.Width - this.ClientSize.Width));
    }
}

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