C read / write application configuration file app exe. Config and display it on the interface

C# Read and write application configuration files App.exe.config, The essence is xml Reading and writing of documents .

We will configure the AppSettings Nodes and ConnectionStrings The content of the node is automatically bound to the grouping box control GroupBox in , At the same time, it can be saved in batches .

One 、 newly build Windows Forms application SaveDefaultXmlConfigDemo, Default Form1 Rename it to FormSaveDefaultXmlConfig.

forms  FormSaveDefaultXmlConfig The design is shown in the picture ：

  Add pair System.Configuration References to .

For form FormSaveDefaultXmlConfig binding Load event FormSaveDefaultXmlConfig_Load

Is a button btnSaveConfig The binding event btnSaveConfig_Click.

Two 、 Default application configuration file App.config The configuration is as follows ：

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
    </startup>
<appSettings>
  <add key="SoftName" value="Sword7" />
  <add key="Supplier" value="SoftStar" />
  <add key="EnabledTcp" value="1" />
</appSettings>
<connectionStrings>
  <add name="DataConnect" providerName="MySql.Data" connectionString="server=127.0.0.1;Database=test;Uid=root;Pwd=root;" />
  <add name="ExternalConnect" providerName="System.Data.SqlClient" connectionString="server=127.0.0.1;Database=external;Uid=root;Pwd=123456;" />
</connectionStrings>
</configuration>

3、 ... and 、 forms FormSaveDefaultXmlConfig The source program is as follows

（ Ignore the code automatically generated by the designer ）：

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

namespace SaveDefaultXmlConfigDemo
{
    public partial class FormSaveDefaultXmlConfig : Form
    {
        public FormSaveDefaultXmlConfig()
        {
            InitializeComponent();
            // Add reference System.Configuration
        }

        private void btnSaveConfig_Click(object sender, EventArgs e)
        {
            try
            {
                Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
                List<Tuple<string, string>> tupleAppSettings = GetAppSettingList();
                for (int i = 0; i < tupleAppSettings.Count; i++)
                {
                    // Modify the configuration node AppSettings The content of 
                    config.AppSettings.Settings[tupleAppSettings[i].Item1].Value = tupleAppSettings[i].Item2;
                }
                List<Tuple<string, string, string>> tupleConnectionStrings = GetConnectionStringList();
                for (int i = 0; i < tupleConnectionStrings.Count; i++)
                {
                    // Modify the configuration node ConnectionStrings The content of 
                    config.ConnectionStrings.ConnectionStrings[tupleConnectionStrings[i].Item1].ProviderName = tupleConnectionStrings[i].Item2;
                    config.ConnectionStrings.ConnectionStrings[tupleConnectionStrings[i].Item1].ConnectionString = tupleConnectionStrings[i].Item3;
                }
                // Save configuration file 
                config.Save();
                MessageBox.Show($" Saving application configuration file succeeded , Start reloading the application configuration .", " Tips ");

                // Refresh configuration 
                FormSaveDefaultXmlConfig_Load(null, e);
            }
            catch (Exception ex)
            {
                MessageBox.Show($" Error saving application configuration file :{ex.Message}", " error ");
            }
        }

        /// <summary>
        ///  Get configuration node AppSettings All of , Add it to the tuple list 
        /// </summary>
        /// <returns></returns>
        private List<Tuple<string, string>> GetAppSettingList()
        {
            List<Tuple<string, string>> tupleAppSettings = new List<Tuple<string, string>>();
            for (int i = 0; i < groupBox1.Controls.Count; i++)
            {
                if (groupBox1.Controls[i] is Label lbl)
                {
                    Control[] controls = groupBox1.Controls.Find($"txtValue{lbl.Tag}", true);
                    if (controls == null || controls.Length == 0)
                    {
                        throw new Exception($" Can't find 【{lbl.Text}】 Corresponding text box control 【txtValue{lbl.Tag}】");
                    }
                    tupleAppSettings.Add(Tuple.Create(lbl.Text, controls[0].Text));
                }
            }
            return tupleAppSettings;
        }

        /// <summary>
        ///  Get configuration node onnectionStrings All of , Add it to the tuple list 
        /// </summary>
        /// <returns></returns>
        private List<Tuple<string, string, string>> GetConnectionStringList()
        {
            List<Tuple<string, string, string>> tupleConnectionStrings = new List<Tuple<string, string, string>>();
            for (int i = 0; i < groupBox2.Controls.Count; i++)
            {
                if (groupBox2.Controls[i] is Label lbl && lbl.Name.StartsWith("lblName"))
                {
                    Control[] controlProviderNames = groupBox2.Controls.Find($"txtProviderName{lbl.Tag}", true);
                    if (controlProviderNames == null || controlProviderNames.Length == 0)
                    {
                        throw new Exception($" Can't find 【{lbl.Text}】 Corresponding text box control 【txtProviderName{lbl.Tag}】");
                    }
                    Control[] controlConnectionStrings = groupBox2.Controls.Find($"txtConnectionString{lbl.Tag}", true);
                    if (controlConnectionStrings == null || controlConnectionStrings.Length == 0)
                    {
                        throw new Exception($" Can't find 【{lbl.Text}】 Corresponding text box control 【txtConnectionString{lbl.Tag}】");
                    }
                    tupleConnectionStrings.Add(Tuple.Create(lbl.Text, controlProviderNames[0].Text, controlConnectionStrings[0].Text));
                }
            }
            return tupleConnectionStrings;
        }

        private void FormSaveDefaultXmlConfig_Load(object sender, EventArgs e)
        {
            try
            {
                Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
                txtFilePath.Text = config.FilePath;
                // Reading configuration AppSetting node ,
                KeyValueConfigurationCollection keyValueCollection = config.AppSettings.Settings;
                AddAppSettingConfig(keyValueCollection);
                // Read connection string ConnectionStrings node 
                ConnectionStringSettingsCollection connectionCollection = config.ConnectionStrings.ConnectionStrings;
                AddConnectionStringConfig(connectionCollection);
            }
            catch (Exception ex)
            {
                MessageBox.Show($" Error loading application configuration file :{ex.Message}", " error ");
            }
        }

        /// <summary>
        ///  Read all AppSetting node , Bind it to groupBox1 in 
        ///  Only consider in the configuration file 【IsPresent by true】 The node of 
        /// </summary>
        /// <param name="keyValueCollection"></param>
        private void AddAppSettingConfig(KeyValueConfigurationCollection keyValueCollection)
        {
            groupBox1.Controls.Clear();
            int index = 0;
            foreach (KeyValueConfigurationElement keyValueElement in keyValueCollection)
            {
                ElementInformation elemInfo = keyValueElement.ElementInformation;
                if (!elemInfo.IsPresent)
                {
                    // Considering that some configurations are not in App.exe.config In profile , Do not handle at this time 
                    continue;
                }
                Label label = new Label();
                label.AutoSize = true;
                label.Location = new System.Drawing.Point(20, 20 + index * 30);
                label.Name = $"lblKey{index + 1}";
                label.Text = keyValueElement.Key;
                label.Tag = index + 1;

                TextBox textBox = new TextBox();
                textBox.Location = new System.Drawing.Point(120, 20 + index * 30);
                textBox.Name = $"txtValue{index + 1}";
                textBox.Size = new System.Drawing.Size(300, 21);
                textBox.Text = keyValueElement.Value;

                groupBox1.Controls.AddRange(new Control[] { label, textBox });
                index++;
            }
        }

        /// <summary>
        ///  Read all ConnectionString node , Bind it to groupBox2 in 
        ///  Only consider in the configuration file 【IsPresent by true】 The node of 
        /// </summary>
        /// <param name="connectionCollection"></param>
        private void AddConnectionStringConfig(ConnectionStringSettingsCollection connectionCollection)
        {
            groupBox2.Controls.Clear();
            int index = 0;
            foreach (ConnectionStringSettings connectElement in connectionCollection)
            {
                ElementInformation elemInfo = connectElement.ElementInformation;
                if (!elemInfo.IsPresent)
                {
                    // Considering that the connection string has the system default configuration , Not in the configuration file 【IsPresent=false】, So filter out , Like the following two 
                    //LocalSqlServer、LocalMySqlServer
                    continue;
                }
                Label label = new Label();
                label.AutoSize = true;
                label.Location = new System.Drawing.Point(20, 20 + index * 30);
                label.Name = $"lblName{index + 1}";
                label.Text = connectElement.Name;
                label.Tag = index + 1;

                TextBox textBox = new TextBox();
                textBox.Location = new System.Drawing.Point(120, 20 + index * 30);
                textBox.Name = $"txtConnectionString{index + 1}";
                textBox.Size = new System.Drawing.Size(360, 21);
                textBox.Text = connectElement.ConnectionString;

                Label lblFixed = new Label();
                lblFixed.AutoSize = true;
                lblFixed.Location = new System.Drawing.Point(500, 20 + index * 30);
                lblFixed.Name = $"lblFixed{index + 1}";
                lblFixed.Text = " Provider name ";

                TextBox txtProviderName = new TextBox();
                txtProviderName.Location = new System.Drawing.Point(580, 20 + index * 30);
                txtProviderName.Name = $"txtProviderName{index + 1}";
                txtProviderName.Size = new System.Drawing.Size(140, 21);
                txtProviderName.Text = connectElement.ProviderName;

                groupBox2.Controls.AddRange(new Control[] { label, textBox, lblFixed, txtProviderName });
                index++;
            }
        }
    }
}

Four 、 The program runs as shown in the figure ：

  After modifying and saving the configuration , open SaveDefaultXmlConfigDemo.exe.Config file