private void initializeTable()

本文介绍了一个使用Java Swing框架初始化表格的方法,包括添加列名、设置列宽,并调整表格大小以适应界面。

    private void initializeTable()
    {
        int i, tWidth = 0;
        TableColumn tc;

        for(i = 0; i < colnames.length; i++)
        {
            modelMONCENTER.addColumn(colnames[i]);
        }
        for(i = 0; i < colnames.length; i++)
        {
            tc = tblMONCENTER.getColumn(colnames[i]);//getColumn(Object identifier) 返回表中列的 TableColumn 对象,
            // tc.setMinWidth(colwidth[i]);
            tc.setPreferredWidth(colwidth[i]);
            tWidth += colwidth[i];
        }
        tblMONCENTER.setPreferredScrollableViewportSize(new Dimension(
                tWidth + 10, 290));

//        tblMONCENTER.setBorder(BorderFactory.createEtchedBorder());
        // tblMONCENTER.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
        tblMONCENTER.setRowSelectionAllowed(true);
        tblMONCENTER.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        scrollPanel.setPreferredSize(new Dimension(550, 400));
    }

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; namespace Session2 { public partial class UserForm : Form { public UserForm() { InitializeComponent(); Table_tre(); } public void Table_tre() { dgv_tra.Rows.Clear(); Dao dao = new Dao(); string sql = $"select * from Manager"; IDataReader dc = dao.read(sql); int IntRow = 0; while (dc.Read()) { dgv_tra.Rows.Add(dc[0].ToString(), dc[1].ToString(), dc[2].ToString(), dc[3].ToString()); IntRow++; } dc.Close(); dao.DaoClose(); } //search public void Table_name() { dgv_tra.Rows.Clear(); Dao dao = new Dao(); string sql = $"select * from Manager where Name like '%{txt_select.Text}%' "; IDataReader dc = dao.read(sql); int IntRow = 0; while (dc.Read()) { dgv_tra.Rows.Add(dc[0].ToString(), dc[1].ToString(), dc[2].ToString(), dc[3].ToString()); IntRow++; } dc.Close(); dao.DaoClose(); } //Auto-refresh data public void shuaxin() { if (string.IsNullOrWhiteSpace(txt_select.Text)) { Table_tre(); } else { Table_name(); } } private void button1_Click(object sender, EventArgs e) { this.Close(); } private void button2_Click(object sender, EventArgs e) { Application.Exit(); } private void dgv_tra_CellContentClick(object sender, DataGridViewCellEventArgs e) { } private void pictureBox4_Click(object sender, EventArgs e) { Table_name(); } private void txt_select_TextChanged(object sender, EventArgs e) { shuaxin(); } } } 增加在状态栏中显示项目数量
最新发布
08-12
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; using System.Data.SqlClient; using System.IO; namespace _2 { public partial class Form2 : Form { private readonly string username; // 唯一声明 private string connectionString = "Data Source=localhost;Initial Catalog=学习笔记管理;Integrated Security=True;"; private OpenFileDialog openFileDialog1 = new OpenFileDialog(); private WebBrowser webBrowser1 = new WebBrowser(); public bool ShouldRelogin { get; private set; } = false; public Form2(string username) { InitializeComponent(); this.username = username; this.Text = $"用户管理 - {username}"; // 初始化控件 openFileDialog1.Filter = "所有文件 (*.*)|*.*"; webBrowser1.Dock = DockStyle.Fill; panel1.Controls.Add(webBrowser1); } private void 打开ToolStripMenuItem_Click(object sender, EventArgs e) { } // 修复 DeleteUserAccount 方法 private bool DeleteUserAccount() { using (SqlConnection conn = new SqlConnection(connectionString)) { try { conn.Open(); string query = "DELETE FROM T_User WHERE Uname = @Username"; using (SqlCommand cmd = new SqlCommand(query, conn)) { cmd.Parameters.Add("@Username", SqlDbType.NVarChar, 50).Value = username; int rowsAffected = cmd.ExecuteNonQuery(); if (rowsAffected > 0) { MessageBox.Show($"账号 {username} 已成功注销", "成功", MessageBoxButtons.OK, MessageBoxIcon.Information); return true; } else { MessageBox.Show($"未找到用户 {username}", "错误", MessageBoxButtons.OK, MessageBoxIcon.Error); return false; } } } catch (SqlException sqlEx) { MessageBox.Show($"数据库错误: {sqlEx.Message}", "SQL错误", MessageBoxButtons.OK, MessageBoxIcon.Error); return false; } catch (Exception ex) { MessageBox.Show($"操作失败: {ex.Message}", "错误", MessageBoxButtons.OK, MessageBoxIcon.Error); return false; } } } // 窗体关闭处理 protected override void OnFormClosing(FormClosingEventArgs e) { base.OnFormClosing(e); // 如果是退出登录/注销账号,不显示确认提示 if (ShouldRelogin) return; if (e.CloseReason == CloseReason.UserClosing) { var result = MessageBox.Show("确定要退出程序吗?", "退出确认", MessageBoxButtons.YesNo, MessageBoxIcon.Question); if (result == DialogResult.No) { e.Cancel = true; } } } private void 退出登录ToolStripMenuItem_Click(object sender, EventArgs e) { if (DialogResult.Yes == MessageBox.Show("确认退出吗?", "消息", MessageBoxButtons.YesNo, MessageBoxIcon.Question)) { ShouldRelogin = true; this.Close(); // 关闭当前窗体 } } private void 注销账号ToolStripMenuItem_Click(object sender, EventArgs e) { DialogResult confirm = MessageBox.Show($"确定要永久删除账号 {username} 吗?", "确认删除", MessageBoxButtons.YesNo, MessageBoxIcon.Warning); if (confirm == DialogResult.Yes && DeleteUserAccount()) { ShouldRelogin = true; this.Close(); // 关闭当前窗体 } } private void 打开ToolStripMenuItem1_Click(object sender, EventArgs e) { // 显示打开文件对话框 if (openFileDialog1.ShowDialog() == DialogResult.OK) { // 获取选中的文件路径 string filePath = openFileDialog1.FileName; try { // 在 WebBrowser 控件中显示文件 webBrowser1.Navigate(filePath); } catch (Exception ex) { MessageBox.Show("打开文件时出错:" + ex.Message); } } } private void 修改密码ToolStripMenuItem_Click(object sender, EventArgs e) { // 直接传递用户名字符串 FormUpdatePwd_User updateForm = new FormUpdatePwd_User(this.username); updateForm.ShowDialog(); } private void panel1_Paint(object sender, PaintEventArgs e) { } private void 修改ToolStripMenuItem_Click(object sender, EventArgs e) { } //点击添加跳转页面 private void 添加ToolStripMenuItem_Click(object sender, EventArgs e) { Addnotepoint addnotepoint = new Addnotepoint(); addnotepoint.ShowDialog(); } private void 修改ToolStripMenuItem1_Click(object sender, EventArgs e) { FormMannage form = new FormMannage(); form.ShowDialog(); } private void 导出ToolStripMenuItem_Click(object sender, EventArgs e) { } private void 查看ToolStripMenuItem_Click(object sender, EventArgs e) { } private void 历史记录ToolStripMenuItem_Click(object sender, EventArgs e) { } } }怎么实现知识点导出、查看、历史记录
07-04
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; using System.Numerics; namespace Form1 { public partial class Form1 : Form { string str1 = "", str2 = "", str3 = ""; public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { } private void btn1_Click(object sender, EventArgs e) { // 正常逻辑:追加数字到 str1 或 str3 if (str2 == "") str1 += "1"; else str3 += "1"; txtExpression.Text += "1"; } private void btn2_Click(object sender, EventArgs e) { if (str2 == "") str1 += "2"; else str3 += "2"; this.txtExpression.Text += "2"; } private void btn3_Click(object sender, EventArgs e) { if (str2 == "") str1 += "3"; else str3 += "3"; this.txtExpression.Text += "3"; } private void btn4_Click(object sender, EventArgs e) { if (str2 == "") str1 += "4"; else str3 += "4"; this.txtExpression.Text +="4"; } private void btn5_Click(object sender, EventArgs e) { if (str2 == "") str1 += "5"; else str3 += "5"; this.txtExpression.Text += "5"; } private void btn6_Click(object sender, EventArgs e) { if (str2 == "") str1 += "6"; else str3 += "6"; this.txtExpression.Text += "6"; } private void btn7_Click(object sender, EventArgs e) { if (str2 == "") str1 += "7"; else str3 += "7"; this.txtExpression.Text += "7"; } private void btn8_Click(object sender, EventArgs e) { if (str2 == "") str1 += "8"; else str3 += "8"; this.txtExpression.Text += "8"; } private void btn9_Click(object sender, EventArgs e) { if (str2 == "") str1 += "9"; else str3 += "9"; this.txtExpression.Text += "9"; } private void btn0_Click(object sender, EventArgs e) { if (str2 == "") str1 += "0"; else str3 += "0"; this.txtExpression.Text += "0"; } private void add_Click(object sender, EventArgs e) { if (str1 == "") { MessageBox.Show("请先输入第一个操作数!","提示" ,MessageBoxButtons.OK ,MessageBoxIcon.Warning); return; } str2 = "+"; this.txtExpression.Text += "+"; } private void btn10_Click(object sender, EventArgs e) { if (str1 == "") { MessageBox.Show("请先输入第一个操作数!", "提示" , MessageBoxButtons.OK , MessageBoxIcon.Warning); return; } str2 = "-"; this.txtExpression.Text += "-"; } private void btn11_Click(object sender, EventArgs e) { if (str1 == "") { MessageBox.Show("请先输入第一个操作数!", "提示" , MessageBoxButtons.OK , MessageBoxIcon.Warning); return; } str2 = "×"; this.txtExpression.Text += "×"; } private void btn12_Click(object sender, EventArgs e) { if (str1 == "") { MessageBox.Show("请先输入第一个操作数!", "提示" , MessageBoxButtons.OK , MessageBoxIcon.Warning); return; } str2 = "÷"; this.txtExpression.Text += "÷"; } private void btnEquals_Click(object sender, EventArgs e) { // 检查是否所有部分都已填写 if (string.IsNullOrEmpty(str1) || string.IsNullOrEmpty(str2) || string.IsNullOrEmpty(str3)) { MessageBox.Show("请输入完整的表达式!", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; } // 解析数字 double a = double.Parse(str1); double b = double.Parse(str3); double result = 0; switch (str2) { case "+": result = a + b; break; case "-": result = a - b; break; case "×": result = a * b; break; case "÷": if (b == 0) { MessageBox.Show("除数不能为零!", "错误", MessageBoxButtons.OK, MessageBoxIcon.Error); return; } result = a / b; break; } this.txtExpression.Text += "=" + result.ToString(); // 重置变量(避免残留数据影响后续计算) str1 = result.ToString(); // 结果可以作为下一次计算的 str1 str2 = ""; str3 = ""; } private void AC_Click(object sender, EventArgs e) { str1 = ""; str2 = ""; str3 = ""; txtExpression.Text = ""; } private void 删除_Click(object sender, EventArgs e) { if (txtExpression.Text.Length > 0) { txtExpression.Text = txtExpression.Text.Substring(0, txtExpression.Text.Length - 1); if (str3 != "") { str3 = str3.Substring(0, str3.Length - 1); } else if (str2 != "") { str2 = ""; // 如果 str2 被删除,直接清空 } else if (str1 != "") { str1 = str1.Substring(0, str1.Length - 1); // 删除 str1 的最后一个字符 } } } private void 左括号_Click(object sender, EventArgs e) { // 只能在表达式开始或运算符后输入左括号 if (str2 == "" && str1 == "" || str2 != "") { txtExpression.Text += "("; } } private void 右括号_Click(object sender, EventArgs e) { if (str1 != "" || str3 != "") { txtExpression.Text += ")"; } } private void 小数点_Click(object sender, EventArgs e) { string currentNum = str2 == "" ? str1 : str3; // 如果当前数字不包含小数点,则添加 if (!currentNum.Contains(".")) { if (str2 == "") { str1 += "."; txtExpression.Text += "."; } else { str3 += "."; txtExpression.Text += "."; } } } } } 检查错误,并完善
07-14
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; namespace WindowsFormsApp1 { public partial class Form1 : Form { private SQLiteConnection connection; private const string dbFile = "knowledge.db"; public Form1() { InitializeComponent(); InitializeDatabase(); LoadSubjects(); } // 初始化数据库 private void InitializeDatabase() { if (!File.Exists(dbFile)) { SQLiteConnection.CreateFile(dbFile); } connection = new SQLiteConnection($"Data Source={dbFile};Version=3;"); connection.Open(); // 创建学科表 string subjectSql = @"CREATE TABLE IF NOT EXISTS Subjects ( Id INTEGER PRIMARY KEY AUTOINCREMENT, Name TEXT NOT NULL UNIQUE)"; // 创建知识点表 string knowledgeSql = @"CREATE TABLE IF NOT EXISTS KnowledgePoints ( Id INTEGER PRIMARY KEY AUTOINCREMENT, SubjectId INTEGER NOT NULL, Title TEXT NOT NULL, Description TEXT, Image BLOB, FOREIGN KEY(SubjectId) REFERENCES Subjects(Id))"; ExecuteNonQuery(subjectSql); ExecuteNonQuery(knowledgeSql); } private void ExecuteNonQuery(string sql) { using (var cmd = new SQLiteCommand(sql, connection)) { cmd.ExecuteNonQuery(); } } // 加载所有学科 private void LoadSubjects() { cmbSubjects.Items.Clear(); string sql = "SELECT Id, Name FROM Subjects"; using (var cmd = new SQLiteCommand(sql, connection)) using (var reader = cmd.ExecuteReader()) { while (reader.Read()) { cmbSubjects.Items.Add(new Subject( reader.GetInt32(0), reader.GetString(1) )); } } } private void 添加新学科ToolStripMenuItem_Click(object sender, EventArgs e) { string subjectName = txtNewSubject.Text.Trim(); if (string.IsNullOrEmpty(subjectName)) { MessageBox.Show("请输入学科名称"); return; } string sql = "INSERT INTO Subjects (Name) VALUES (@name)"; using (var cmd = new SQLiteCommand(sql, connection)) { cmd.Parameters.AddWithValue("@name", subjectName); cmd.ExecuteNonQuery(); } txtNewSubject.Clear(); LoadSubjects(); MessageBox.Show("学科添加成功!"); } private void 添加知识点ToolStripMenuItem_Click(object sender, EventArgs e) { if (cmbSubjects.SelectedItem == null) { MessageBox.Show("请先选择学科"); return; } var subject = (Subject)cmbSubjects.SelectedItem; string title = txtTitle.Text.Trim(); string description = txtDescription.Text; if (string.IsNullOrEmpty(title)) { MessageBox.Show("请输入知识点标题"); return; } // 处理图片 byte[] imageBytes = null; if (picImage.Image != null) { using (var ms = new MemoryStream()) { picImage.Image.Save(ms, picImage.Image.RawFormat); imageBytes = ms.ToArray(); } } // 插入数据库 string sql = @"INSERT INTO KnowledgePoints (SubjectId, Title, Description, Image) VALUES (@subjectId, @title, @desc, @image)"; using (var cmd = new SQLiteCommand(sql, connection)) { cmd.Parameters.AddWithValue("@subjectId", subject.Id); cmd.Parameters.AddWithValue("@title", title); cmd.Parameters.AddWithValue("@desc", description); cmd.Parameters.AddWithValue("@image", imageBytes ?? (object)DBNull.Value); cmd.ExecuteNonQuery(); } ClearKnowledgeForm(); MessageBox.Show("知识点添加成功!"); } private void 上传图片ToolStripMenuItem_Click(object sender, EventArgs e) { using (OpenFileDialog dlg = new OpenFileDialog()) { dlg.Filter = "图片文件|*.jpg;*.jpeg;*.png;*.bmp"; if (dlg.ShowDialog() == DialogResult.OK) { picImage.Image = new Bitmap(dlg.FileName); } } } private void ClearKnowledgeForm() { txtTitle.Clear(); txtDescription.Clear(); picImage.Image = null; } private void 查看知识点ToolStripMenuItem_Click(object sender, EventArgs e) { var viewForm = new KnowledgeViewer(connection); viewForm.ShowDialog(); } } public class Subject { public int Id { get; } public string Name { get; } public Subject(int id, string name) { Id = id; Name = name; } public override string ToString() => Name; } }using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; namespace KnowledgeViewer { public partial class Form1 : Form { private TreeView treeView; private WebBrowser browser; private SQLiteConnection connection; public KnowledgeViewer(SQLiteConnection conn) { connection = conn; InitializeUI(); LoadData(); } private void InitializeUI() { this.Size = new Size(800, 600); this.Text = "知识点浏览器"; SplitContainer split = new SplitContainer(); split.Dock = DockStyle.Fill; split.SplitterDistance = 200; treeView = new TreeView(); treeView.Dock = DockStyle.Fill; treeView.AfterSelect += TreeView_AfterSelect; browser = new WebBrowser(); browser.Dock = DockStyle.Fill; split.Panel1.Controls.Add(treeView); split.Panel2.Controls.Add(browser); this.Controls.Add(split); } private void LoadData() { // 加载学科 string subjectSql = "SELECT Id, Name FROM Subjects"; using (var cmd = new SQLiteCommand(subjectSql, connection)) using (var reader = cmd.ExecuteReader()) { while (reader.Read()) { var subjectNode = new TreeNode(reader.GetString(1)) { Tag = $"Subject_{reader.GetInt32(0)}" }; treeView.Nodes.Add(subjectNode); LoadKnowledgePoints(subjectNode, reader.GetInt32(0)); } } } private void LoadKnowledgePoints(TreeNode parentNode, int subjectId) { string sql = "SELECT Id, Title FROM KnowledgePoints WHERE SubjectId = @subjectId"; using (var cmd = new SQLiteCommand(sql, connection)) { cmd.Parameters.AddWithValue("@subjectId", subjectId); using (var reader = cmd.ExecuteReader()) { while (reader.Read()) { var pointNode = new TreeNode(reader.GetString(1)) { Tag = $"Point_{reader.GetInt32(0)}" }; parentNode.Nodes.Add(pointNode); } } } } public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { } private void treeView1_AfterSelect(object sender, TreeViewEventArgs e) { if (e.Node.Tag == null) return; var parts = e.Node.Tag.ToString().Split('_'); if (parts[0] == "Point") { int pointId = int.Parse(parts[1]); DisplayKnowledgePoint(pointId); } } private void DisplayKnowledgePoint(int pointId) { string sql = "SELECT Title, Description, Image FROM KnowledgePoints WHERE Id = @id"; using (var cmd = new SQLiteCommand(sql, connection)) { cmd.Parameters.AddWithValue("@id", pointId); using (var reader = cmd.ExecuteReader()) { if (reader.Read()) { string title = reader.GetString(0); string description = reader.GetString(1); byte[] imageBytes = reader.IsDBNull(2) ? null : (byte[])reader[2]; string html = $"<h1>{title}</h1><p>{description.Replace("\n", "<br>")}</p>"; if (imageBytes != null) { string base64 = Convert.ToBase64String(imageBytes); html += $"<img src='data:image/png;base64,{base64}' style='max-width:100%'/>"; } browser.DocumentText = html; } } } } } 怎么改
07-03
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