当Panel.AutoSize = true时添加控件后Panel.Size何时更新？

Question

我正在使用WinForms在C#中创建GUI . 我试图将programaticaly创建的面板放在另一个下面.由于这些面板的内容可能会根据其内容而有所不同,我正在使用WinForms执行正确的大小调整.
Panel.AutoSize

问题是:如果我在填充后立即使用Panel.Height(或Panel.Size.Height)Panel,则返回的值始终是我的默认值.调整大小确实发生了,正如我在启动应用程序时所看到的那样,但我只是不知道何时.

这是我正在做的简化版本:

this.SuspendLayout();

int yPos = 0;
foreach (String entry in entries)
{
    Panel panel = new Panel();
    panel.SuspendLayout();
    panel.AutoSize = true;
    panel.AutoSizeMode = System.Windows.Forms.AutoSizeMode.GrowOnly;
    panel.BackColor = System.Drawing.SystemColors.Window; // Allows to see that the panel is resized for dispay
    panel.Location = new System.Drawing.Point(0, yPos);
    panel.Size = new System.Drawing.Size(this.Width, 0);
    this.Controls.Add(panel);

    Label label = new Label();
    label.AutoSize = true;
    label.Location = new System.Drawing.Point(0, 0);
    label.MaximumSize = new System.Drawing.Size(panel.Width, 0);
    label.Text = entry;
    panel.Controls.Add(label);

    panel.ResumeLayout(false);
    panel.PerformLayout();

    yPos += panel.Height; // When breaking here, panel.Height is worth 0
    yPos += label.Height; // This works perfectly, label.Height was updated according to the text content when breaking at that point
}

this.ResumeLayout(false);
this.PerformLayout();

所以真正的问题是:如何Panel.Size在添加控件后获得更新,以获得适当的高度值？

注意:我知道我可以使用TextBox高度,但我发现它不优雅且不切实际,因为在我的实际代码中有更多的控件Panel,我需要使用下面几行的面板高度.

Answer 1

我正在发生的事情是,当您对其Parent执行PerformLayout时,将确定Panel的大小.您可以通过将面板的父SuspendLayout / ResumeLayout代码移动到循环中来使其工作正常.

int yPos = 0;
foreach (String entry in entries)
{
    this.SuspendLayout();
    Panel panel = new Panel();
    panel.SuspendLayout();
    panel.AutoSize = true;
    panel.AutoSizeMode = System.Windows.Forms.AutoSizeMode.GrowOnly;
    panel.BackColor = System.Drawing.SystemColors.Window; // Allows to see that the panel is resized for dispay
    panel.Location = new System.Drawing.Point(0, yPos);
    panel.Size = new System.Drawing.Size(this.Width, 0);
    this.Controls.Add(panel);

    Label label = new Label();
    label.AutoSize = true;
    label.Location = new System.Drawing.Point(0, 0);
    label.MaximumSize = new System.Drawing.Size(panel.Width, 0);
    label.Text = entry;
    panel.Controls.Add(label);
    panel.ResumeLayout(true);
    this.ResumeLayout(true);
    yPos += panel.Height; // When breaking here, panel.Height is worth 0
    //yPos += label.Height; // This works perfectly, label.Height was updated according to the text content when breaking at that point
}
this.PerformLayout();