自定义组件--动态创建的控件无法正常显示

[phhui]

想自己写一个gridview组件，逻辑是从其它语言搬过来修改的
改好后编译正常，运行后却只能看到第一个子元件，
其它都看不到，也没报错
断点了各子元件创建也正常，赋值也都有执行，但就是无法正常显示，
哪位朋友有空帮忙看下什么原因

启动界面

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using SalesManage.UI;
using System.Collections;

namespace SalesManage
{
    public partial class fertilizerType : Form
    {
        public fertilizerType()
        {
            InitializeComponent();
        }

        private void fertilizerType_Load(object sender, EventArgs e)
        {

            PQGrid g = new PQGrid(4,4,30, 30);//创建组件
            ArrayList al = new ArrayList();
            for (int i = 0; i < 20; i++)
            {//创建模拟数据
                ArrayList a = new ArrayList();
                a.Add("aa"+i.ToString());
                a.Add("ab" + i.ToString());
                a.Add("ac" + i.ToString());
                a.Add("ad" + i.ToString());
                al.Add(a);
            }
            g.bindData(al, "SalesManage.UI.PQGItem");//绑定数据
            this.Controls.Add(g);//添加到窗口
        }
    }
}

自定义组件 gridview

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Collections;

namespace SalesManage.UI
{
    public partial class PQGrid : UserControl
    {
        public int _rowNum;
        public int _columnNum;
        public string _direction = "v";
        private int _columnWidth;
        private int _rowHeight;
        private int _spaceV=5;
        private int _spaceH=5;
        private ArrayList _item = new ArrayList();
        private Point point = new Point();
        public PQGrid(int rowNum,int columnNum,int columnWidth, int rowHeight)
        {//设置组件行列数及单元格宽高
            InitializeComponent();
            _rowNum = rowNum;
            _columnNum = columnNum;
            _columnWidth = columnWidth;
            _rowHeight = rowHeight;
            Size s=new Size();
            s.Width=columnNum*columnWidth;
            s.Height=rowNum*rowHeight;
            this.Size = s;
        }
        public PQGrid(int rowNum,int columnNum,int cw, int rh,int spaceV,int spaceH)
        {
            InitializeComponent();
            _rowNum = rowNum;
            _columnNum = columnNum;
            _columnWidth = cw;
            _rowHeight = rh;
            _spaceH = spaceH;
            _spaceV = spaceV;
        }
        public void bindData(ArrayList al,string item)
        {//根据数据源动态创建子元件并排列
            int n = al.Count;
			if(n<1)return;
			int pNum = Convert.ToInt32(Math.Round(n / (_rowNum * _columnNum)+0.5));//计算页数
			int itemNum = 0;
            Type type = Type.GetType(item);
			for (int p = 0; p < pNum;p++){
				for (int i = 0; i < _rowNum; i++) {
					for (int j = 0; j < _columnNum;j++){
                        Object obj=Activator.CreateInstance(type);//创建子元件实例
						point.X = j % _columnNum * (_columnWidth + _spaceH) + _spaceH;
						point.Y = i * (_rowHeight + _spaceV) + _spaceV;
						if (_direction == "v")point.Y += p * (_rowNum * (_rowHeight + _spaceV) + _spaceV);
						else point.X += p * (_columnNum * (_columnWidth + _spaceH) + _spaceH);
                        ((Control)obj).Location=point;//设置坐标
						this.Controls.Add((Control)obj);//添加子元件到组件上
                        ((IPQGItem)obj).bindData((ArrayList)al[itemNum]);//为子元件绑定数据
						itemNum++;
						if (itemNum > n - 1)return;
					}
				}
			}
        }
    }
}

组件元件

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Collections;

namespace SalesManage.UI
{
    public partial class PQGItem : UserControl,IPQGItem
    {
        public PQGItem()
        {
            InitializeComponent();
        }


        public void bindData(ArrayList al)
        {
            Label tb = new Label();
            tb.Text = al[0].ToString();
            tb.BringToFront();
            this.Controls.Add(tb);
        }
    }
}

接口

using System.Collections;

namespace SalesManage.UI
{
    interface IPQGItem
    {
        void bindData(ArrayList al);
    }
    
}

[phhui]

编译后结果只有一个，无法看到其它格子

[devmiao]

a.Add("aa"+i.ToString()); a.Add("ab" + i.ToString()); a.Add("ac" + i.ToString()); a.Add("ad" + i.ToString()); al.Add(a); 这些类型都有么？ ((IPQGItem)obj).bindData((ArrayList)al[itemNum]);//为子元件绑定数据 调用的是 Label tb = new Label(); tb.Text = al[0].ToString(); tb.BringToFront(); this.Controls.Add(tb); 那么位置有设置么？

[phhui]

引用 2 楼 devmiao 的回复:

a.Add("aa"+i.ToString()); a.Add("ab" + i.ToString()); a.Add("ac" + i.ToString()); a.Add("ad" + i.ToString()); al.Add(a); 这些类型都有么？ ((IPQGItem)obj).bindData((ArrayList)al[itemNum]);//为子元件绑定数据 调用的是 Label tb = new Label(); tb.Text = al[0].ToString(); tb.BringToFront(); this.Controls.Add(tb); 那么位置有设置么？

模拟数据都只是字符串而已，不需要其它处理 label位置没有设置，label本身添加到PQGItem中，一个PQGItem只有一个label 而PQGrid有对PQGItem位置进行设置了。

[phhui]