INI文件的结构

INI文件是一种按照特点方式排列的文本文件。每一个INI文件构成都非常类似，由若干段落（section）组成，在每个带括号的标题下面，是若干个以单个单词开头的关键词（keyword）和一个等号，等号右边的就是关键字对应的值（value）。其一般形式如下：

[Section1]

　　KeyWord1 = Valuel

　　KeyWord2 = Value2

　　　……

　　[Section2]

　　KeyWord3 = Value3

　　KeyWord4 = Value4

本文中介绍的程序设计及运行环境：

● 微软视窗2000 高级服务器版

● .Net Framework SDK正式版

C＃和Win32 API函数

C＃并不像C＋＋，拥有属于自己的类库。C＃使用的类库是.Net框架为所有.Net程序开发提供的一个共有的类库——.Net FrameWork SDK。虽然.Net FrameWork SDK内容十分庞大，功能也非常强大，但还不能面面俱到，至少它并没有提供直接操作INI文件所需要的相关的类。在本文中，C＃操作INI文件使用的是Windows系统自带Win32的API函数——WritePrivateProfileString（）和GetPrivateProfileString（）函数。这二个函数都位于“kernel32.dll”文件中。

我们知道在C＃中使用的类库都是托管代码（Managed Code）文件，而Win32的API函数所处的文件，都是非托管代码（Unmanaged Code）文件。这就导致了在C＃中不可能直接使用这些非托管代码文件中的函数。好在.Net框架为了保持对下的兼容，也为了充分利用以前的资源，提出了互操作，通过互操作可以实现对Win32的API函数的调用。互操作不仅适用于Win32的API函数，还可以用来访问托管的COM对象。C＃中对Win32的API函数的互操作是通过命名空间“System.Runtime.InteropServices”中的“DllImport”特征类来实现的。它的主要作用是指示此属性化方法是作为非托管DLL的输出实现的。下面代码就是在C＃利用命名空间“System.Runtime.InteropServices”中的“DllImport”特征类申明上面二个Win32的API函数：

C＃申明INI文件的写操作函数WritePrivateProfileString（）：

         [ DllImport ( "kernel32" ) ]

         private static extern long WritePrivateProfileString ( string section , string key , string val , string filePath ) ;

参数说明：section：INI文件中的段落；key：INI文件中的关键字；val：INI文件中关键字的数值；filePath：INI文件的完整的路径和名称。

C＃申明INI文件的读操作函数GetPrivateProfileString（）：

         [ DllImport ( "kernel32" ) ]

         private static extern int GetPrivateProfileString ( string section ,string key , string def , StringBuilder retVal , int size , string filePath ) ;

参数说明：section：INI文件中的段落名称；key：INI文件中的关键字；def：无法读取时候时候的缺省数值；retVal：读取数值；size：数值的大小；filePath：INI文件的完整路径和名称。

C＃中读写INI文件的关键步骤和解决方法

C＃对INI文件进行写操作：

         //写入INI文件

         private void button2_Click ( object sender , System.EventArgs e )

         {

              string FileName = textBox1.Text ;

              string section = textBox2.Text ;

              string key = textBox3.Text ;

              string keyValue = textBox4.Text ;

              WritePrivateProfileString ( section , key , keyValue , FileName ) ;

              MessageBox.Show( “成功写入INI文件！” , “信息” ) ;

         }

对INI文件进行写操作，是通过组件button2的”Click”事件来实现的。这里有一点应该注意，当在调用WritePrivateProfileString（）对INI文件进行写操作的时候，如果此时在INI文件中存在和要写入的信息相同的段落名称和关键字，则将覆盖此INI信息。下面是button2组件的”Click”事件对应的代码清单：

C＃对INI文件进行读操作：

正确读取INI的必须满足三个前提：INI文件的全路径、段落名称和关键字名称。否则就无法正确读取。你可以设定读取不成功后的缺省数值，在下面的程序中，为了直观设定的是“无法读取对应数值！”字符串，读取INI文件是通过button3组件的“Click”事件来实现的，下面是其对应的代码清单：

         //读取指定INI文件的特定段落中的关键字的数值

         private void button3_Click ( object sender , System.EventArgs e )

         {

              StringBuilder temp = new StringBuilder ( 255 ) ;

              string FileName = textBox1.Text ;

              string section = textBox2.Text ;

              string key = textBox3.Text ;

              int i = GetPrivateProfileString ( section , key ,

                   “无法读取对应数值！” , temp , 255 , FileName ) ;

              //显示读取的数值

              textBox4.Text = temp.ToString();

         }

C＃操作INI文件的完整源代码（ini.cs）和运行界面

通过上面的这些介绍，我们不难得到用C＃操作INI文件的完整代码清单（ini.cs），具体如下：

using System ;

using System.Drawing ;

using System.Collections ;

using System.ComponentModel ;

using System.Windows.Forms ;

using System.Data ;

using System.Runtime.InteropServices ;

using System.Text ;

namespace C_ReadIni

{

     public class Form1 : System.Windows.Forms.Form

     {

         private System.Windows.Forms.Button button1 ;

         private System.Windows.Forms.TextBox textBox1 ;

         private System.Windows.Forms.Button button2 ;

         private System.Windows.Forms.TextBox textBox2 ;

         private System.Windows.Forms.TextBox textBox3 ;

         private System.Windows.Forms.TextBox textBox4 ;

         private System.Windows.Forms.Label label1 ;

         private System.Windows.Forms.Label label2 ;

         private System.Windows.Forms.Label label3 ;

         private System.Windows.Forms.Button button3 ;

         private System.Windows.Forms.OpenFileDialog openFileDialog1 ;

         private System.ComponentModel.Container components = null ;

         public Form1 ( )

         {

              InitializeComponent ( ) ;

         }

         protected override void Dispose (bool disposing)

         {

              if (disposing)

              {

                   if(components != null)

                   {

                       components.Dispose ( ) ;

                   }

              }

              base.Dispose (disposing);

         }

         [ DllImport ( "kernel32" ) ]

         private static extern long WritePrivateProfileString ( string section , string key , string val , string filePath ) ;

         [ DllImport ( "kernel32" ) ]

         private static extern int GetPrivateProfileString ( string section ,string key , string def , StringBuilder retVal ,

              int size , string filePath ) ;

         private void InitializeComponent ( )

         {

              this.button1 = new System.Windows.Forms.Button ( ) ;

              this.textBox1 = new System.Windows.Forms.TextBox ( ) ;

              this.button2 = new System.Windows.Forms.Button ( ) ;

              this.textBox2 = new System.Windows.Forms.TextBox ( ) ;

              this.textBox3 = new System.Windows.Forms.TextBox ( ) ;

              this.textBox4 = new System.Windows.Forms.TextBox ( ) ;

              this.label1 = new System.Windows.Forms.Label ( ) ;

              this.label2 = new System.Windows.Forms.Label ( ) ;

              this.label3 = new System.Windows.Forms.Label ( ) ;

              this.button3 = new System.Windows.Forms.Button ( ) ;

              this.openFileDialog1 = new

                   System.Windows.Forms.OpenFileDialog ( ) ;

              this.SuspendLayout ( ) ;

              this.button1.FlatStyle = System.Windows.Forms.FlatStyle.Flat ;

              this.button1.Location = new System.Drawing.Point ( 238 , 20 ) ;

              this.button1.Name = “button1″ ;

              this.button1.Size = new System.Drawing.Size ( 100 , 32 ) ;

              this.button1.TabIndex = 0 ;

              this.button1.Text = “选择INI文件” ;

              this.button1.Click += new System.EventHandler ( this.button1_Click ) ;

              this.textBox1.Location = new System.Drawing.Point ( 58 , 22 ) ;

              this.textBox1.Name = “textBox1″ ;

              this.textBox1.Size = new System.Drawing.Size ( 162 , 21 ) ;

              this.textBox1.TabIndex = 1 ;

              this.textBox1.Text = “” ;

              this.button2.FlatStyle = System.Windows.Forms.FlatStyle.Flat ;

              this.button2.Location = new System.Drawing.Point ( 86 , 168 ) ;

              this.button2.Name = “button2″ ;

              this.button2.Size = new System.Drawing.Size ( 98 , 30 ) ;

              this.button2.TabIndex = 3 ;

              this.button2.Text = “写入INI文件” ;

              this.button2.Click += new System.EventHandler ( this.button2_Click ) ;

              this.textBox2.Location = new System.Drawing.Point ( 160 , 62 ) ;

              this.textBox2.Name = “textBox2″ ;

              this.textBox2.Size = new System.Drawing.Size ( 176 , 21 ) ;

              this.textBox2.TabIndex = 5 ;

              this.textBox2.Text = “” ;

              this.textBox3.Location = new System.Drawing.Point ( 160 , 94 ) ;

              this.textBox3.Name = “textBox3″ ;

              this.textBox3.Size = new System.Drawing.Size ( 176 , 21 ) ;

              this.textBox3.TabIndex = 6 ;

              this.textBox3.Text = “” ;

              this.textBox4.Location = new System.Drawing.Point ( 160 , 128 ) ;

              this.textBox4.Name = “textBox4″ ;

              this.textBox4.Size = new System.Drawing.Size ( 176 , 21 ) ;

              this.textBox4.TabIndex = 7 ;

              this.textBox4.Text = “” ;

              this.label1.Location = new System.Drawing.Point ( 56 , 62 ) ;

              this.label1.Name = “label1″ ;

              this.label1.TabIndex = 8 ;

              this.label1.Text = “段落名称：” ;

              this.label2.Location = new System.Drawing.Point ( 66 , 96 ) ;

              this.label2.Name = “label2″ ;

              this.label2.TabIndex = 9 ;

              this.label2.Text = “关键字：” ;

              this.label3.Location = new System.Drawing.Point ( 42 , 130 ) ;

              this.label3.Name = “label3″ ;

              this.label3.TabIndex = 10 ;

              this.label3.Text = “关键字数值：” ;

              this.button3.FlatStyle = System.Windows.Forms.FlatStyle.Flat ;

              this.button3.Location = new System.Drawing.Point ( 208 , 168 ) ;

              this.button3.Name = “button3″ ;

              this.button3.Size = new System.Drawing.Size ( 98 , 30 ) ;

              this.button3.TabIndex = 11 ;

              this.button3.Text = “读取INI数值” ;

              this.button3.Click += new System.EventHandler ( this.button3_Click ) ;

              this.openFileDialog1.Filter = “INI 文件|*.ini” ;

              this.AutoScaleBaseSize = new System.Drawing.Size ( 6 , 14 ) ;

              this.ClientSize = new System.Drawing.Size ( 366 , 217 ) ;

              this.Controls.AddRange ( new System.Windows.Forms.Control [ ] {

                                                                                           this.button3 ,

                                                                                           this.textBox4 ,

                                                                                           this.textBox3 ,

                                                                                           this.textBox2 ,

                                                                                           this.button2 ,

                                                                                           this.textBox1 ,

                                                                                           this.button1 ,

                                                                                           this.label3 ,

                                                                                           this.label2 ,

                                                                                           this.label1 } ) ;

              this.MaximizeBox = false ;

              this.Name = “Form1″ ;

              this.Text = “C＃操作INI文件–写操作” ;

              this.ResumeLayout ( false ) ;

         }

         [STAThread]

         static void Main ( )

         {

              Application.Run ( new Form1 ( )) ;

         }

         private void button1_Click ( object sender , System.EventArgs e )

         {

              openFileDialog1.ShowDialog ( ) ;

              textBox1.Text = openFileDialog1.FileName ;

         }

         //写入INI文件

         private void button2_Click ( object sender , System.EventArgs e )

         {

              string FileName = textBox1.Text ;

              string section = textBox2.Text ;

              string key = textBox3.Text ;

              string keyValue = textBox4.Text ;

              WritePrivateProfileString ( section , key , keyValue , FileName ) ;

              MessageBox.Show( “成功写入INI文件！” , “信息” ) ;

         }

         //读取指定INI文件的特定段落中的关键字的数值

         private void button3_Click ( object sender , System.EventArgs e )

         {

              StringBuilder temp = new StringBuilder ( 255 ) ;

              string FileName = textBox1.Text ;

              string section = textBox2.Text ;

              string key = textBox3.Text ;

              int i = GetPrivateProfileString ( section , key ,

                   “无法读取对应数值！” , temp , 255 , FileName ) ;

              //显示读取的数值

              textBox4.Text = temp.ToString();

         }

     }

}