在 WinForm C# 中单击按钮时更改表格单元格颜色

Posted 2023-04-11

【中文标题】在 WinForm C# 中单击按钮时更改表格单元格颜色

【英文标题】：Change table cell color when a button is clicked in WinForm C#

【发布时间】：2021-02-22 08:45:18

【问题描述】：

我是 Windows 窗体的新手，已经寻找了三天的答案，但没有运气。

我有一个按钮和一个包含多个单元格的表格。

单击按钮时，我需要更改左上角单元格的颜色（索引 [0, 0]），但我不明白该怎么做，因为the button's on-click event method 没有 TableLayoutCellPaintEventArgs 元素类型参数。

请告知如何做。

【问题讨论】：

这能回答你的问题吗？ How to set cell color in TableLayoutPanel dynamically?

您现在需要展示如何绘制单元格。从按钮单击事件处理程序中，您必须以某种方式与绘画代码进行通信：将某个变量设置为某个值并强制重新绘画，检查绘画代码中的该变量以改变颜色。

【参考方案1】：

表格单元格重绘事件可用于在运行时更改单元格颜色。

下面的例子是创建颜色数组来保存表格中每个单元格的颜色，并使用单元格重绘事件来绘制它。

每次点击按钮都会改变随机选择的单元格的颜色。

Form1.cs

namespace WindowsFormsTable

    public partial class Form1 : Form
    
        private Color[,] cellColors = null;
        private Random rnd = new Random();

        public Form1()
        
            InitializeComponent();    

            // Prepare random colors for table cells
            var columns = tableLayoutPanel1.ColumnCount;
            var rows = tableLayoutPanel1.RowCount;                
            cellColors = new Color[columns, rows];

            for (int c = 0; c < columns; c++)
            
                for (int r = 0; r < rows; r++)
                
                    // Get random color
                    cellColors[c, r] = GetRandomColor();
                
            
        
        // Table cell is redrawn event handler
        private void tableLayoutPanel1_CellPaint(object sender, TableLayoutCellPaintEventArgs e)
        
            if (cellColors != null)
            
                var color = cellColors[e.Column, e.Row];
                e.Graphics.FillRectangle(new SolidBrush(color), e.CellBounds);
                      
        

        private void button1_Click(object sender, EventArgs e)
        
            // Change color for randow cell
            var column = rnd.Next(0, tableLayoutPanel1.ColumnCount - 1);
            var row = rnd.Next (0, tableLayoutPanel1.RowCount-1);
            cellColors[column, row] = GetRandomColor();
            tableLayoutPanel1.Refresh();

            // To change color of the top left cell remove code above and uncomment the following code line: 
            // cellColors[0, 0] = Color.FromArgb( /* define you color */ );
        

        private Color GetRandomColor()
        
            return Color.FromArgb(rnd.Next(0, 255), rnd.Next(0, 255), rnd.Next(0, 255));
        
    

Form1.Designer.cs

namespace WindowsFormsTable

    partial class Form1
    
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        
            if (disposing && (components != null))
            
                components.Dispose();
            
            base.Dispose(disposing);
        

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        
            this.tableLayoutPanel1 = new System.Windows.Forms.TableLayoutPanel();
            this.button1 = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // tableLayoutPanel1
            // 
            this.tableLayoutPanel1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
            | System.Windows.Forms.AnchorStyles.Left) 
            | System.Windows.Forms.AnchorStyles.Right)));
            this.tableLayoutPanel1.ColumnCount = 4;
            this.tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 25F));
            this.tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 25F));
            this.tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 25F));
            this.tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 25F));
            this.tableLayoutPanel1.Location = new System.Drawing.Point(12, 46);
            this.tableLayoutPanel1.Name = "tableLayoutPanel1";
            this.tableLayoutPanel1.RowCount = 4;
            this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 25F));
            this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 25F));
            this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 25F));
            this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 25F));
            this.tableLayoutPanel1.Size = new System.Drawing.Size(410, 256);
            this.tableLayoutPanel1.TabIndex = 1;
            this.tableLayoutPanel1.CellPaint += new System.Windows.Forms.TableLayoutCellPaintEventHandler(this.tableLayoutPanel1_CellPaint);
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(12, 12);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(89, 23);
            this.button1.TabIndex = 0;
            this.button1.Text = "Change Color";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(434, 314);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.tableLayoutPanel1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.ResumeLayout(false);

        

        #endregion
        private System.Windows.Forms.TableLayoutPanel tableLayoutPanel1;
        private System.Windows.Forms.Button button1;
    

【参考方案2】：

感谢 Jackdaw 的回答，我能够找到适合我的解决方案：

我在 tableLayoutPanel1_CellPaint 事件处理程序中更改表格单元格的颜色，然后使用此脚本从按钮的事件处理程序调用它：

this.tableLayoutPanel1.CellPaint += new TableLayoutCellPaintEventHandler(tableLayoutPanel1_CellPaint);

我缺少 tableLayoutPanel1.Refresh();部分，但在寒鸦的回答之后，我注意到并能够添加它。现在一切正常。

完整的脚本如下所示：

    private void tableLayoutPanel1_CellPaint(object sender, TableLayoutCellPaintEventArgs e)
    
        if (e.Row == 0 && e.Column == 2)
            e.Graphics.FillRectangle(Brushes.Red, e.CellBounds);
    

    private void button1_Click(object sender, EventArgs e)
    
        this.tableLayoutPanel1.CellPaint += new TableLayoutCellPaintEventHandler(tableLayoutPanel1_CellPaint);
        tableLayoutPanel1.Refresh();
    

感谢您的帮助！