winform自定义控件(UserControl)加载慢的研究-YES开发框架网

winform项目中，现有一个自定义控件 uc_test , 该控件中又foreach 添加了数个自定义控件 uc_unit ，

项目运行，因用了该控件的form初始化加载慢要很长时间，

分析得出耗时的操作出现在uc_test的初始化(构造函数) 过程

解决办法：

将uc_unit的逻辑，在uc_test用原生代码实现，减少自定义控件的使用，效率有点提升，但是没有明显提升

继续分析，得出是foreach循环生成控件慢，继续跟踪得出生成控件时添加了一些事件导致很慢，如果把事件加载去掉，加载就很快了

那么可以先界面显示控件，然后再启用异步设置事件，测试效果还行

结论：

1. 页面中尽量避免使用大量的自定义控件，特别是 foreach 循环加载

2. 尽量使用代码组合原生的控件来添加到界面

3. 批量控件事件设置采用异步的方法

List<Control> childs = new List<Control>();
foreach (var v in dataSource)
{
    var col = this.GenerateItem(v);
    childs.Insert(0, col);
}
panel1.Controls.AddRange(childs.ToArray());
Task.Run(() =>
{
    foreach (var v in childs)
    {
        v.Click += Uc_Click;
    }
});

GarsonZhang www.yesdotnet.com

GenerateItem 方法：

Panel GenerateItem(ItemData item)
{
    Panel panel = new Panel();
    panel.Width = 180;
    panel.Dock = DockStyle.Left;
    panel.Cursor = Cursors.Hand;
    panel.Tag = item;
    //panel.Click += Uc_Click;

    // title
    Label lblTitle = new Label();
    lblTitle.Text = item.Title;
    lblTitle.AutoSize = true;
    lblTitle.Font = new System.Drawing.Font("宋体", 14F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
    lblTitle.Location = new System.Drawing.Point(9, 11);
    //lblTitle.Size = new System.Drawing.Size(150, 19);
    //lblTitle.Click += (sender, obj) => Uc_Click(panel1, obj);
    panel.Controls.Add(lblTitle);

    // num
    Label lbl_Num = new Label();
    lbl_Num.Text = item.NuM;
    lbl_Num.Font = new System.Drawing.Font("宋体", 24F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
    lbl_Num.Location = new System.Drawing.Point(9, 33);
    lbl_Num.AutoSize = true;
    //lbl_Num.Click += (sender, obj) => Uc_Click(panel1, obj);
    panel.Controls.Add(lbl_Num);


    FlowLayoutPanel flowLayoutPanel1 = new FlowLayoutPanel();
    flowLayoutPanel1.Location = new System.Drawing.Point(9, 69);
    flowLayoutPanel1.Name = "flowLayoutPanel1";
    flowLayoutPanel1.Size = new System.Drawing.Size(200, 27);
    //flowLayoutPanel1.Click += (sender, obj) => Uc_Click(panel1, obj);
    panel.Controls.Add(flowLayoutPanel1);

    // preTitle
    Label pre1Title = new Label();
    pre1Title.Text = item.Pre1Txt;
    pre1Title.Location = new System.Drawing.Point(3, 0);
    pre1Title.Padding = new System.Windows.Forms.Padding(0, 6, 0, 0);
    pre1Title.AutoSize = true;
    //pre1Title.Click += (sender, obj) => Uc_Click(panel1, obj);

    flowLayoutPanel1.Controls.Add(pre1Title);

    // preNum
    Label pre1Num = new Label();
    pre1Num.Text = item.Pre1Num;
    pre1Num.Location = new System.Drawing.Point(56, 0);
    pre1Num.Padding = new System.Windows.Forms.Padding(0, 6, 0, 0);
    pre1Num.AutoSize = true;
    //pre1Num.Click += (sender, obj) => Uc_Click(panel1, obj);

    flowLayoutPanel1.Controls.Add(pre1Num);
    if (!(String.IsNullOrWhiteSpace(item.Pre1Num) || item.Pre1Num == "-"))
    {
        PictureEdit pictureEdit1 = new PictureEdit();
        pictureEdit1.Properties.Appearance.BackColor = System.Drawing.Color.Transparent;
        pictureEdit1.Properties.Appearance.Options.UseBackColor = true;
        pictureEdit1.Properties.BorderStyle = DevExpress.XtraEditors.Controls.BorderStyles.NoBorder;
        pictureEdit1.Properties.ShowCameraMenuItem = DevExpress.XtraEditors.Controls.CameraMenuItemVisibility.Auto;
        pictureEdit1.Properties.SizeMode = DevExpress.XtraEditors.Controls.PictureSizeMode.Stretch;
        pictureEdit1.Size = new System.Drawing.Size(16, 16);
        if (item.Pre1Type == EnumNumType.UP)
        {
            pictureEdit1.EditValue = global::XQ.AliAdminTool.UI.Properties.Resources.moveup_16x16;
            pre1Num.ForeColor = Color.Red;
        }
        else
        {
            pictureEdit1.EditValue = global::XQ.AliAdminTool.UI.Properties.Resources.movedown_16x16;
            pre1Num.ForeColor = Color.Green;
        }
        flowLayoutPanel1.Controls.Add(pictureEdit1);
    }

    FlowLayoutPanel flowLayoutPanel2 = new FlowLayoutPanel();
    flowLayoutPanel2.Location = new System.Drawing.Point(9, 90);
    flowLayoutPanel2.Name = "flowLayoutPanel1";
    flowLayoutPanel2.Size = new System.Drawing.Size(200, 27);
    //flowLayoutPanel2.Click += (sender, obj) => Uc_Click(panel1, obj);

    panel.Controls.Add(flowLayoutPanel2);

    // preTitle
    Label pre2Title = new Label();
    pre2Title.Text = item.Pre2Txt;
    pre2Title.Location = new System.Drawing.Point(3, 0);
    pre2Title.Padding = new System.Windows.Forms.Padding(0, 6, 0, 0);
    pre2Title.AutoSize = true;
    //pre2Title.Click += (sender, obj) => Uc_Click(panel1, obj);
    flowLayoutPanel2.Controls.Add(pre2Title);

    // preNum
    Label pre2Num = new Label();
    pre2Num.Text = item.Pre2Num;
    pre2Num.Location = new System.Drawing.Point(56, 0);
    pre2Num.Padding = new System.Windows.Forms.Padding(0, 6, 0, 0);
    pre2Num.AutoSize = true;
    //pre2Num.Click += (sender, obj) => Uc_Click(panel1, obj);
    flowLayoutPanel2.Controls.Add(pre2Num);

    if (!(String.IsNullOrWhiteSpace(item.Pre2Num) || item.Pre2Num == "-"))
    {
        PictureEdit pictureEdit = new PictureEdit();
        pictureEdit.Properties.Appearance.BackColor = System.Drawing.Color.Transparent;
        pictureEdit.Properties.Appearance.Options.UseBackColor = true;
        pictureEdit.Properties.BorderStyle = DevExpress.XtraEditors.Controls.BorderStyles.NoBorder;
        pictureEdit.Properties.ShowCameraMenuItem = DevExpress.XtraEditors.Controls.CameraMenuItemVisibility.Auto;
        pictureEdit.Properties.SizeMode = DevExpress.XtraEditors.Controls.PictureSizeMode.Stretch;
        pictureEdit.Size = new System.Drawing.Size(16, 16);
        if (item.Pre2Type == EnumNumType.UP)
        {
            pictureEdit.EditValue = global::XQ.AliAdminTool.UI.Properties.Resources.moveup_16x16;
            pre2Num.ForeColor = Color.Red;
        }
        else
        {
            pictureEdit.EditValue = global::XQ.AliAdminTool.UI.Properties.Resources.movedown_16x16;
            pre2Num.ForeColor = Color.Green;
        }
        flowLayoutPanel2.Controls.Add(pictureEdit);
    }

    return panel;
}

GarsonZhang www.yesdotnet.com