我如何将form1变量传递给用户控制类

本文关键字：给用户 控制 变量 form1 | 更新日期: 2023-09-27 18:03:43

我有这个用户控件代码，用户控件是GraphChart:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Web;
using System.Windows.Forms.DataVisualization.Charting;
namespace GatherLinks
{
    public partial class GraphChart : UserControl
    {
        Form1 form1;
        public GraphChart(Form1 f1)
        {
            InitializeComponent();
            form1 = f1;
        }
        private void GraphChart_Load(object sender, EventArgs e)
        {
            chart1.Series.Clear();
            var series1 = new System.Windows.Forms.DataVisualization.Charting.Series
            {
                Name = "Series1",
                Color = System.Drawing.Color.Green,
                IsVisibleInLegend = false,
                IsXValueIndexed = true,
                ChartType = SeriesChartType.Line
            };
            this.chart1.Series.Add(series1);
            //for (int i = 0; i < 100; i++)
            //{
                series1.Points.AddXY(form1.axisX, form1.axisY);
            //}
            chart1.Invalidate();
        }

添加form1和f1变量后出现错误:

错误2:GatherLinks。GraphChart'不包含接受0个参数的构造函数

当我双击错误时它会移动到Form1 designer cs的位置

this.graphChart1 = new GatherLinks.GraphChart();

我试图把Form1在()之间，但它不工作得到一个错误。我该如何解决这个问题?

编辑:

我刚刚在用户控制代码中做了:

public partial class GraphChart : UserControl
    {
        Form1 form1;
        public GraphChart() { }
        public GraphChart(Form1 f1)
        {
            InitializeComponent();
            form1 = f1;
        }

但是现在在Form1构造函数中，我有这几行:

this.graphChart1.chart1.MouseMove += chart1_MouseMove;
this.graphChart1.chart1.MouseLeave += chart1_MouseLeave;

他们工作之前很好，但一旦我添加行:当运行应用程序时，我得到一个错误，chart1为null。

我如何将form1变量传递给用户控制类

您的第一个问题是您的UserControl不知道Form1类型是什么。你需要把一个using语句在你的文件的顶部，包括你的表单名称空间，在我的情况下，我用WindowsFormApplication1测试，虽然它将是你使用的任何名称空间。在你更新的例子中，你从来没有调用你的InitializeComponent方法，所以你从来没有创建你的图表。

如果您想使用无参数构造函数，您可以尝试这样做:(注意，向默认构造函数添加了InitializeComponent方法，并添加了两个额外的方法SetupGraph和SetForm。我还将代码从GraphChart_Load事件处理程序移到了SetupGraph方法。只要在调用SetupGraph )

之前使用SetForm，就可以在构造函数中传递Form1和使用无参数构造函数。

用户控件

public partial class GraphChart : UserControl
{
    private Chart chart1;
    Form1 form1;
    public GraphChart()
    {
        InitializeComponent();
    }
    public GraphChart(Form1 f1)
    {
        InitializeComponent();
        form1 = f1;
        this.Load+=new EventHandler(GraphChart_Load);
    }
    public void SetForm( Form1 f1)
    {
        form1 = f1;
    }
    public void SetupGraph()
    {
        chart1.Series.Clear();
        var series1 = new System.Windows.Forms.DataVisualization.Charting.Series
        {
            Name = "Series1",
            Color = System.Drawing.Color.Green,
            IsVisibleInLegend = false,
            IsXValueIndexed = true,
            ChartType = SeriesChartType.Line
        };
        this.chart1.Series.Add(series1);
        //for (int i = 0; i < 100; i++)
        //{
        series1.Points.AddXY(form1.axisX, form1.axisY);
        //}
        chart1.Invalidate();
    }
    private void GraphChart_Load(object sender, EventArgs e)
    {
        SetupGraph();
    }
    private void InitializeComponent()
    {
        System.Windows.Forms.DataVisualization.Charting.ChartArea chartArea1 = new System.Windows.Forms.DataVisualization.Charting.ChartArea();
        System.Windows.Forms.DataVisualization.Charting.Legend legend1 = new System.Windows.Forms.DataVisualization.Charting.Legend();
        System.Windows.Forms.DataVisualization.Charting.Series series1 = new System.Windows.Forms.DataVisualization.Charting.Series();
        this.chart1 = new System.Windows.Forms.DataVisualization.Charting.Chart();
        ((System.ComponentModel.ISupportInitialize)(this.chart1)).BeginInit();
        this.SuspendLayout();
        // 
        // chart1
        // 
        chartArea1.Name = "ChartArea1";
        this.chart1.ChartAreas.Add(chartArea1);
        legend1.Name = "Legend1";
        this.chart1.Legends.Add(legend1);
        this.chart1.Location = new System.Drawing.Point(0, 0);
        this.chart1.Name = "chart1";
        series1.ChartArea = "ChartArea1";
        series1.Legend = "Legend1";
        series1.Name = "Series1";
        this.chart1.Series.Add(series1);
        this.chart1.Size = new System.Drawing.Size(519, 473);
        this.chart1.TabIndex = 0;
        this.chart1.Text = "chart1";
        // 
        // GraphChart
        // 
        this.Controls.Add(this.chart1);
        this.Name = "GraphChart";
        ((System.ComponentModel.ISupportInitialize)(this.chart1)).EndInit();
        this.ResumeLayout(false);
    }
}

Form1 

public partial class Form1 : Form
{
    public int axisX = 100;
    public int axisY = 100;
    GatherLinks.GraphChart graphChart1;
    public Form1()
    {
        InitializeComponent();
    }
    private void button1_Click(object sender, EventArgs e)
    {
        graphChart1 = new GatherLinks.GraphChart();
        this.Controls.Add(graphChart1);
        graphChart1.SetForm(this);
        graphChart1.SetupGraph();
    }
}

您需要为类提供一个接受0个参数的构造函数，因此尝试将以下行添加到类GraphChart:

public GraphChart(){}
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