C＃表单未呈现控件

Question

I have a small popup window like so:

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

namespace SQLProcWriter
{
    public partial class Progress : Form
    {
        public Progress()
        {
            InitializeComponent();
            progressBar1.Minimum = 0;
            progressBar1.Maximum = 100;
        }
    }
}

namespace SQLProcWriter
{
    partial class Progress
    {
        /// <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()
        {
            System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Progress));
            this.progressBar1 = new System.Windows.Forms.ProgressBar();
            this.label1 = new System.Windows.Forms.Label();
            this.SuspendLayout();
            // 
            // progressBar1
            // 
            resources.ApplyResources(this.progressBar1, "progressBar1");
            this.progressBar1.Name = "progressBar1";
            this.progressBar1.UseWaitCursor = true;
            // 
            // label1
            // 
            resources.ApplyResources(this.label1, "label1");
            this.label1.Name = "label1";
            this.label1.UseWaitCursor = true;
            // 
            // Progress
            // 
            resources.ApplyResources(this, "$this");
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.Controls.Add(this.label1);
            this.Controls.Add(this.progressBar1);
            this.Name = "Progress";
            this.UseWaitCursor = true;
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        public System.Windows.Forms.ProgressBar progressBar1;
        public System.Windows.Forms.Label label1;
    }
}

It's supposed to show the progress of a file I'm loading and processing. The problem is that it doesn't render the progress bar or the label until after the file is finished processing; the form is created on the main windows' load method, and shown once an openfiledialog has completed with an 'OK' result. Any help?

EDIT: The code for the setting of the value is quite extensive, so I originally opted to remove it, but here it is:

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

namespace SQLProcWriter
{
    public partial class Form1 : Form
    {
        private string Script { get; set; }
        private List<string> File { get; set; }
        private List<string> CreateStatements { get; set; }
        private List<Table> Tables { get; set; }
        private List<string> FieldBuffer { get; set; }
        private Progress progressWindow;
        private int progressValue;

        private const string CREATE_SEPARATOR = "create table ";
        private string[] FIELD_SEPARATOR = new string[] { @"\t", @" "};

        public Form1()
        {
            InitializeComponent();
            File = new List<string>();
            FieldBuffer = new List<string>();
            Tables = new List<Table>();
            CreateStatements = new List<string>();
            progressValue = 0;
            progressWindow = new Progress();
        }

        private void aboutToolStripMenuItem_Click(object sender, EventArgs e)
        {
            About about = new About();
            about.Show();
        }

        private void Convert()
        {
            bool adding = false, nullableBuffer = false;
            string buffer = "", buffer2 = "";
            Table currentTable = new Table();
            currentTable.ForeignKeys = new List<ForeignKey>();
            currentTable.Columns = new List<Column>();
            int startIndex = 0, endIndex = 0;
            int linesDone = 0;
            int totalLines = File.Count();
            progressWindow.label1.Text = "Reading \'Create\' Statements";

            foreach (string s in File)
            {
                //Extract column names
                if (adding)
                {
                    if (s.Contains(@")") && s.Length == 1)
                    {
                        adding = false;
                        Tables.Add(currentTable);
                        currentTable = new Table();
                        currentTable.Columns = new List<Column>();
                        currentTable.ForeignKeys = new List<ForeignKey>();
                        currentTable.TableName = "";
                        currentTable.PrimaryKey = new PrimaryKey();
                    }
                    else
                    {
                        if (s != @"(")
                        {
                            if (s != "\t")
                            {
                                if (s.Contains("constraint"))
                                {
                                    //Constraint rules here
                                    if (s.Contains("primary key clustered"))
                                    {
                                        startIndex = s.IndexOf("(");
                                        startIndex++;
                                        endIndex = s.IndexOf(")");

                                        buffer = s.Substring(startIndex, (endIndex - startIndex));


                                        currentTable.PrimaryKey = new PrimaryKey(buffer, "int");
                                    }
                                    else if (s.Contains("foreign key"))
                                    {
                                        startIndex = s.IndexOf("(");
                                        startIndex++;
                                        endIndex = s.IndexOf(")");
                                        buffer = s.Substring(startIndex, (endIndex - startIndex));

                                        startIndex = s.IndexOf("references ");
                                        startIndex += 11;
                                        endIndex = s.Length;

                                        buffer2 = s.Substring(startIndex, (endIndex - startIndex));
                                        endIndex = buffer2.IndexOf(String.Format("({0}", buffer));
                                        buffer2 = buffer2.Substring(0, endIndex);


                                        currentTable.ForeignKeys.Add(new ForeignKey(buffer, buffer2));
                                    }
                                }
                                else
                                {
                                    //Regular table field
                                    buffer = s.Substring(s.IndexOf("\t") + 1, s.IndexOf(" "));

                                    startIndex = s.IndexOf(" ");
                                    startIndex++;
                                    endIndex = s.IndexOf(",");

                                    buffer2 = s.Substring(startIndex, (endIndex - startIndex));

                                    if (buffer2.Contains("not null"))
                                    {
                                        nullableBuffer = false;
                                        buffer2 = buffer2.Remove(buffer2.IndexOf(" "));
                                    }
                                    else
                                        nullableBuffer = true;

                                    currentTable.Columns.Add(new Column(buffer, buffer2, nullableBuffer));
                                }
                            }
                        }
                    }
                }

                //Extract Table Names
                if (s.Contains(CREATE_SEPARATOR))
                {
                    adding = true;
                    buffer = s;
                    currentTable.TableName = buffer.Remove(0, 13);
                }

                linesDone++;
                progressValue = (((linesDone / totalLines) * 100) / 4) + 25;
                progressWindow.progressBar1.Value = progressValue;
            }

            ProcessForeignKeys();
            ProcessPrimaryKeys();
            Tables = Utils.TrimEverything(Tables);
        }

        private void ProcessForeignKeys()
        {
            int keysDone = 0;
            int totalKeys = 0;
            progressWindow.label1.Text = "Processing Foreign Keys";

            foreach (Table t in Tables)
                foreach (ForeignKey fk in t.ForeignKeys)
                    totalKeys++;

            foreach (Table t in Tables)
                foreach (ForeignKey fk in t.ForeignKeys)
                {
                    for (int i = 0; i < t.Columns.Count; i++)
                        if (t.Columns[i].Name.Contains(fk.Name))
                        {
                            fk.DataType = t.Columns[i].DataType;
                            t.Columns.RemoveAt(i);
                        }

                    keysDone++;
                    progressValue = (((keysDone / totalKeys) * 100) / 4) + 50;
                }
        }

        private void ProcessPrimaryKeys()
        {
            int primaryKeys = 0;
            int totalKeys = Tables.Count();
            progressWindow.label1.Text = "Processing Primary Keys";

            foreach (Table t in Tables)
            {
                for (int i = 0; i < t.Columns.Count; i++)
                {
                    if (t.Columns[i].DataType.Contains("identity"))
                    {
                        t.Columns.RemoveAt(i);
                        primaryKeys++;
                        progressValue = (((primaryKeys / totalKeys) * 100) / 4) + 75;
                        progressWindow.progressBar1.Value = progressValue;
                    }
                }
            }

            progressWindow.label1.Text = "Done!";
            progressWindow.Hide();
            progressWindow.progressBar1.Value = 0;
            progressWindow.label1.Text = "";
            progressValue = 0;
        }

        private void openToolStripMenuItem_Click(object sender, EventArgs e)
        {
            OutputTextBox.Text = "";
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.InitialDirectory = Environment.SpecialFolder.MyDocuments.ToString();
            ofd.Filter = "SQL Script File (.sql)|*.sql";
            ofd.Multiselect = false;
            ofd.Title = "Select an SQL Script File";

            Stream fileStream = null;

            int currentLine = 0;
            int totalLines = 0;

            if (ofd.ShowDialog() == DialogResult.OK)
            {
                progressWindow.Show();

                if ((fileStream = ofd.OpenFile()) != null)
                {
                    TextReader tr = new StreamReader(fileStream);
                    string line;
                    totalLines = System.IO.File.ReadLines(ofd.FileName).Count();

                    while ((line = tr.ReadLine()) != null)
                    {
                        File.Add(line);
                        OutputTextBox.Text += line + "\r\n";

                        currentLine++;
                        progressValue = (int)(((currentLine / totalLines) * 100) / 4);
                        progressWindow.progressBar1.Value = progressValue;
                    }

                    Convert();
                }
            }
        }

        private void CancelButton_Click(object sender, EventArgs e)
        {
            Script = string.Empty;
            OutputTextBox.Text = string.Empty;
        }

        private void quitToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void ConvertButton_Click(object sender, EventArgs e)
        {
            List<string> Output = new List<string>();
            progressWindow.Show();
            progressWindow.label1.Text = "Creating SQL";
            int total = Tables.Count();
            int done = 0;

            Output.Add(String.Format("--Auto-generated code (c) {0} Logic & Design", System.DateTime.Now.Year));

            foreach (Table t in Tables)
            {
                //Add a comment
                Output.Add(String.Format("--Procs for {0}", t.TableName));

                #region List
                Output.Add(String.Format("create proc {0}_List", t.TableName));
                Output.Add("as");
                Output.Add(String.Format("\tselect * from {0}", t.TableName));
                #endregion

                #region Get
                Output.Add(String.Format("create proc {0}_Get", t.TableName));
                Output.Add(String.Format("@{0} {1}", t.PrimaryKey.Name, t.PrimaryKey.DataType));
                Output.Add("as");
                Output.Add(String.Format("\tif"));
                #endregion

                #region Create
                #endregion

                #region Update
                #endregion

                #region Delete
                #endregion

                done++;
                progressValue = (done / total) * 100;
                progressWindow.progressBar1.Value = progressValue;
            }
        }
    }
}

Answer 1

I suggest you let the file be opened asynchronously. Maybe call BeginOpenFile or some similar, let the completion function update the progress bar to 100 or 99 percent then close it via Form.Invoke or similar. Meanwhile have a timer inside the progress form that advances 10% progress once a given number of milliseconds, say 100ms. but don't let it set the progress after reaching 90 percent. You can't tell for sure how much time will it take to open the file, you can only estimate. That's why progress bars in any application tend not to be accurate.

Note: not sure if timer resolution can be smaller than a second (1000ms)...

If you need to learn about asynchronous operations in C# a good resource is "CLR via C#". If you can't have that book try googling for "performing asynchrounos IO operation .NET" and look into a code example for File.BeginRead for example.

And don't forget the Form.Invoke thing.

Answer 2

Control.Invoke executes the specified delegate on the thread that owns the control's window handle, so you can simply call:

//Indicate that the process has started
        Invoke(ShowStatusDelegate, this.toolStripStatusLabelSpinner, true, this.toolStripStatusLabelText, "In progress...", btnGo, false);

assuming the action is threaded or processed.