在FlowLayoutPanel中将多行控件居中 [英] Center multiple rows of controls in a FlowLayoutPanel

问题描述

我正在尝试制作一个面板，以承载动态添加的控件.有两个警告:

I'm trying to make a panel that would host dynamically added controls. There are two caveats:

• 将会有很多控件，因此面板在达到宽度限制并垂直滚动时应将元素包装到新行中.
• 控件可以更改大小，这将更改元素的数量
  可以放入一行.

• There are going to be a lot of controls, so the panel should wrap the elements into new rows as it reaches its width limits and scroll vertically.
• Controls can change in size, which would change the number of elements
  that can fit into a single row.

我已经看到了一些提议的解决方案，用于将动态控件集中在窗体中，但由于以下原因而拒绝了它们:

I've seen a couple proposed solutions to center dynamic controls in a Form and rejected those for following reasons:

• TableLayoutPanel-使用此对象时遇到的主要问题是 元素生长，必须从3-2网格转换为2-4， TableLayoutPanel似乎不能很好地处理这些问题.
• 可以在内部放大和缩小的AutoSize FlowLayoutPanel TableLayoutControl-这个解决方案的主要问题是 仅将表格内的一行居中，一旦换行到新行， 元素开始向右对齐.我想我可以动态地 将新的FlowLayoutPanels添加到TableLayoutControl的新行中，然后 我有一个与第一种情况类似的问题，在这种情况下，我需要手动进行 如果行大小增加/缩小，则在行之间重新分配元素.

• TableLayoutPanel - main issue I have with using this are the events when elements grown and have to shift from 3-2 grid to 2-4, as TableLayoutPanel does not seem to deal well with those.
• AutoSize FlowLayoutPanel that can grow and shrink inside of TableLayoutControl - my main problem with this solution is that it only centers one row inside the Form, once it wraps to a new row, the elements start to align to the right side. I suppose I can dynamically add new FlowLayoutPanels to new rows of a TableLayoutControl, but then I have a similar issue as the first scenario where I need to manually redistribute elements between rows if they grow/shrink in size.

我想知道我是否缺少一些可以帮助我处理增长/收缩事件而无需创建自己的TableLayoutPanel变体的功能?

I was wondering if I'm missing some functionality that can help me handle grows/shrink event without creating my own variation of TableLayoutPanel?

以下是功能草案:

Below is a draft of functionality:

• A-以面板为中心的两个元素
• B-添加了第三个元素，所有三个元素居中
• C-已添加Forth元素，将其包装到新行并居中
• D-元素已放大，现在环绕在第二个元素上，居中

推荐答案

以下是一个重现您描述的行为的示例.
它利用了承载多个FlowLayoutPanel的TableLayoutPanel.

Here's an example that reproduces the behaviour you described.
It makes use of a TableLayoutPanel which hosts multiple FlowLayoutPanels.

一个重要的细节是子FlowLayoutPanels的锚定:它们需要锚定到 Top-Bottom :这会使面板位于TableLayoutPanel行的中心.

One important detail is the anchoring of the child FlowLayoutPanels: they need to be anchored to Top-Bottom: this causes the panel to be positioned in the center of a TableLayoutPanel Row.

请注意，在Form构造函数中， RowStyles 之一已被删除.这也是非常重要的:即使您只有一行(或同一列)，TLP(这是一个很古怪的家伙)也将保留2个RowStyles.第二种样式将应用于您添加的第一行；仅针对第一个，而不是其他:这可能会破坏布局.

Note that, in the Form constructor, one of the RowStyles is removed. This is also very important: the TLP (which is quite the eccentric guy), even if you have just one Row (or one Column, same thing), will keep 2 RowStyles. The second style will be applied to the first Row you add; just to the first one, not the others: this can screw up the layout.

另一个异常，它没有提供删除行的方法，所以我做了一个.它功能齐全，但很简单，需要扩展，包括进一步的验证.

Another anomaly, it doesn't provide a method to remove a Row, so I've made one. It's functional but bare-bones and needs to be extended, including further validations.

有关当前功能，请参见图形示例.如果您在实施其他方面需要帮助，请发表评论.

See the graphic sample about the current functionality. If you need help in implementing something else, leave a comment.

要构建此控件，请将以下控件添加到窗体(此处称为 FLPTest1 ):

To build this add the following controls to a Form (here, called FLPTest1):

1. 添加一个面板，设置为Dock.Bottom.右键单击SendToBack()
2. 添加TableLayoutPanel(在这里称为 tlp1 )，设置为:
   • AutoScroll = true，AutoSize = true，
   • AutoSizeMode = GrowAndShrink，Dock.Fill
   • 保留1列，设置为自动调整大小"，保留1行，设置为自动调整大小"

1. Add one Panel, set Dock.Bottom. Right click and SendToBack(),
2. Add a TableLayoutPanel (here, called tlp1), set:
   • AutoScroll = true, AutoSize = true,
   • AutoSizeMode = GrowAndShrink, Dock.Fill
   • Keep 1 Column, set to AutoSize and one Row, set to AutoSize

• 将其锚点设置为 Top, Bottom <= ，这是!important，如果没有它，布局将无法正常工作:它允许将FLP居中在TLP行内部
• AutoSize = true，AutoSizeMode = GrowAndShrink

• Set its Anchor to Top, Bottom <= this is !important, the layout won't work correctly without it: it allows to center the FLP inside the TLP Row,
• AutoSize = true, AutoSizeMode = GrowAndShrink

---

---

using System.Drawing;
using System.Linq;
using System.Windows.Forms;


public partial class TLPTest1 : Form
{
    public TLPTest1()
    {
        InitializeComponent();
        this.tlp1.RowStyles.RemoveAt(1);
    }

    private void TLPTest1_Load(object sender, EventArgs e)
    {
        PictureBox pBox = new PictureBox() {
            Anchor = AnchorStyles.None,
            BackColor = Color.Orange,
            MinimumSize = new Size(125, 125),
            Size = new Size(125, 125),
        };
        this.flp1.Controls.Add(pBox);
        this.tlp1.Controls.Add(flp1);
    }

    Random rnd = new Random();
    Size[] sizes = new Size[] { new Size(75, 75), new Size(100, 100), new Size(125, 125)};
    Color[] colors = new Color[] { Color.Red, Color.LightGreen, Color.YellowGreen, Color.SteelBlue };
    Control selectedObject = null;

    private void btnAddControl_Click(object sender, EventArgs e)
    {
        Size size = new Size(125, 125);
        if (this.chkRandom.Checked)
            size = sizes[rnd.Next(sizes.Length)];

        PictureBox pBox = new PictureBox() {
            Anchor = AnchorStyles.None,
            BackColor = colors[rnd.Next(colors.Length)],
            MinimumSize = size,
            Size = size
        };

        bool drawborder = false;
        pBox.MouseEnter += (s, evt) => { drawborder = true;  pBox.Invalidate(); };
        pBox.MouseLeave += (s, evt) => { drawborder = false; pBox.Invalidate(); };
        pBox.MouseDown += (s, evt) => { selectedObject = pBox;  pBox.Invalidate(); };
        pBox.Paint += (s, evt) => { if (drawborder) {
                ControlPaint.DrawBorder(evt.Graphics, pBox.ClientRectangle, 
                                        Color.White, ButtonBorderStyle.Solid);
            }
        };

        var ctl = this.tlp1.GetControlFromPosition(0, this.tlp1.RowCount - 1);
        int overallWith = ctl.Controls.OfType<Control>().Sum(c => c.Width + c.Margin.Left + c.Margin.Right);
        overallWith += (ctl.Margin.Right + ctl.Margin.Left);
        if ((overallWith + pBox.Size.Width + pBox.Margin.Left + pBox.Margin.Right) >= this.tlp1.Width)
        {
            var flp = new FlowLayoutPanel() {
                Anchor = AnchorStyles.Top | AnchorStyles.Bottom,
                AutoSize = true,
                AutoSizeMode = AutoSizeMode.GrowAndShrink,
            };
            flp.Controls.Add(pBox);

            this.tlp1.SuspendLayout();
            this.tlp1.RowCount += 1;
            this.tlp1.Controls.Add(flp, 0, this.tlp1.RowCount - 1);
            this.tlp1.ResumeLayout(true);
        }
        else
        {
            ctl.Controls.Add(pBox);
        }
    }

    private void btnRemoveControl_Click(object sender, EventArgs e)
    {
        if (selectedObject is null) return;
        Control parent = selectedObject.Parent;
        selectedObject.Dispose();
        if (parent?.Controls.Count == 0)
        {
            TLPRemoveRow(this.tlp1, parent);
            parent.Dispose();
        }
    }

    private void TLPRemoveRow(TableLayoutPanel tlp, Control control)
    {
        int ctlPosition = this.tlp1.GetRow(control);
        if (ctlPosition < this.tlp1.RowCount - 1)
        {
            for (int i = ctlPosition; i < this.tlp1.RowCount - 1; i++)
            {
                tlp.SetRow(tlp.GetControlFromPosition(0, i + 1), i);
            }
        }
        tlp.RowCount -= 1;
    }
}

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