示例

此代码示例使用 DllImport 将 winmm.dll 的 PlaySound 方法入口点作为 Form1 PlaySound() 导入。该示例具有一个带有一个按钮的简单 Windows 窗体。单击该按钮可打开标准 Windows OpenFileDialog 对话框，以便打开要播放的文件。选择波形文件后，将使用 winmm.DLL 程序集方法的 PlaySound() 方法来播放此文件。有关 winmm.dll 的 PlaySound 方法的更多信息，请参见使用 PlaySound 函数播放波形音频文件。浏览并选择一个带 .wav 扩展名的文件，然后单击“打开”以使用平台调用播放该波形文件。将在文本框中显示选择的文件的完整路径。

“打开文件”对话框将使用以下筛选器设置只显示具有 .wav 扩展名的文件：

C#	复制代码
dialog1.Filter = "Wav Files (.wav)\|.wav";

C#	复制代码
using System.Windows.Forms; using System.Runtime.InteropServices; namespace WinSound { public partial class Form1 : Form { private TextBox textBox1; private Button button1; public Form1() //constructor { InitializeComponent(); } [System.Runtime.InteropServices.DllImport("winmm.DLL", EntryPoint = "PlaySound", SetLastError = true, CharSet = CharSet.Unicode, ThrowOnUnmappableChar = true)] private static extern bool PlaySound(string szSound, System.IntPtr hMod, PlaySoundFlags flags); [System.Flags] public enum PlaySoundFlags : int { SND_SYNC = 0x0000, SND_ASYNC = 0x0001, SND_NODEFAULT = 0x0002, SND_LOOP = 0x0008, SND_NOSTOP = 0x0010, SND_NOWAIT = 0x00002000, SND_FILENAME = 0x00020000, SND_RESOURCE = 0x00040004 } private void button1_Click (object sender, System.EventArgs e) { OpenFileDialog dialog1 = new OpenFileDialog(); dialog1.Title = "Browse to find sound file to play"; dialog1.InitialDirectory = @"c:\"; dialog1.Filter = "Wav Files (.wav)\|.wav"; dialog1.FilterIndex = 2; dialog1.RestoreDirectory = true; if(dialog1.ShowDialog() == DialogResult.OK) { textBox1.Text = dialog1.FileName; PlaySound (dialog1.FileName, new System.IntPtr(), PlaySoundFlags.SND_SYNC); } } } }

复制代码

using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace WinSound
{
    public partial class Form1 : Form
    {
        private TextBox textBox1;
        private Button button1;

        public Form1()  //constructor
        {
            InitializeComponent();
        }

        [System.Runtime.InteropServices.DllImport("winmm.DLL", EntryPoint = "PlaySound", SetLastError = true, CharSet = CharSet.Unicode, ThrowOnUnmappableChar = true)]
        private static extern bool PlaySound(string szSound, System.IntPtr hMod, PlaySoundFlags flags);

        [System.Flags] 
        public enum PlaySoundFlags : int
        {
            SND_SYNC = 0x0000,
            SND_ASYNC = 0x0001, 
            SND_NODEFAULT = 0x0002, 
            SND_LOOP = 0x0008, 
            SND_NOSTOP = 0x0010,
            SND_NOWAIT = 0x00002000, 
            SND_FILENAME = 0x00020000, 
            SND_RESOURCE = 0x00040004 
        }

        private void button1_Click (object sender, System.EventArgs e)
        {
            OpenFileDialog dialog1 = new OpenFileDialog(); 

            dialog1.Title = "Browse to find sound file to play";
            dialog1.InitialDirectory = @"c:\";
            dialog1.Filter = "Wav Files (*.wav)|*.wav";
            dialog1.FilterIndex = 2;
            dialog1.RestoreDirectory = true;

            if(dialog1.ShowDialog() == DialogResult.OK) 
            { 
                textBox1.Text = dialog1.FileName;
                PlaySound (dialog1.FileName, new System.IntPtr(), PlaySoundFlags.SND_SYNC);
            } 
        }
    }
}

编译代码

在 Visual Studio 中创建一个新的 C# Windows 应用程序项目，并命名为 WinSound。
复制上面的代码并将其粘贴到 Form1.cs 文件中以覆盖原来的内容。

复制下面的代码，并将它粘贴到 Form1.Designer.cs 文件的 InitializeComponent() 方法中现有代码的后面。

C#	复制代码
this.button1 = new System.Windows.Forms.Button(); this.textBox1 = new System.Windows.Forms.TextBox(); this.SuspendLayout(); // // button1 // this.button1.Location = new System.Drawing.Point(192, 40); this.button1.Name = "button1"; this.button1.Size = new System.Drawing.Size(88, 24); this.button1.TabIndex = 0; this.button1.Text = "Browse"; this.button1.Click += new System.EventHandler(this.button1_Click); // // textBox1 // this.textBox1.Location = new System.Drawing.Point(8, 40); this.textBox1.Name = "textBox1"; this.textBox1.Size = new System.Drawing.Size(168, 20); this.textBox1.TabIndex = 1; this.textBox1.Text = "FIle path"; // // Form1 // this.AutoScaleDimensions = new System.Drawing.SizeF(5, 13); this.ClientSize = new System.Drawing.Size(292, 266); this.Controls.Add(this.textBox1); this.Controls.Add(this.button1); this.Name = "Form1"; this.Text = "Platform Invoke WinSound C#"; this.ResumeLayout(false); this.PerformLayout();

复制代码

this.button1 = new System.Windows.Forms.Button();
this.textBox1 = new System.Windows.Forms.TextBox();
this.SuspendLayout();
// 
// button1
// 
this.button1.Location = new System.Drawing.Point(192, 40);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(88, 24);
this.button1.TabIndex = 0;
this.button1.Text = "Browse";
this.button1.Click += new System.EventHandler(this.button1_Click);
// 
// textBox1
// 
this.textBox1.Location = new System.Drawing.Point(8, 40);
this.textBox1.Name = "textBox1";
this.textBox1.Size = new System.Drawing.Size(168, 20);
this.textBox1.TabIndex = 1;
this.textBox1.Text = "FIle path";
// 
// Form1
// 
this.AutoScaleDimensions = new System.Drawing.SizeF(5, 13);
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.Add(this.textBox1);
this.Controls.Add(this.button1);
this.Name = "Form1";
this.Text = "Platform Invoke WinSound C#";
this.ResumeLayout(false);
this.PerformLayout();

编译并运行代码。

安全性

有关更多信息，请参见 .NET Framework Security（.NET Framework 安全性）。

请参见

任务

平台调用技术示例

概念

C# 编程指南

参考

互操作性概述（C# 编程指南）

其他资源

用平台调用封送数据