Visual Studio下C#.NET项目调用DLL报错求助

我使用Visual Studio、C#和.NET Framework进行开发，按照教程操作至4分20秒时，测试程序出现DLL相关错误。已尝试Visual Studio提供的基础修复建议但未解决问题，以下是我的代码及错误截图：

代码片段 #

Form1.cs #

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

namespace Energy_Organizer
{
    public partial class Form1 : Form
    {
        private bool drag;
        private int mouseX;
        private int mouseY;

        private const int WM_NCHITTEST = 0x84;
        private const int HTCLIENT = 0x1;
        private const int HTCAPTION = 0x2;

        private bool m_aeroEnabled;

        private const int CS_DROPSHADOW = 0x00020000;
        private const int WM_NCPAINT = 0x0085;
        private const int WM_ACTIVEAPP = 0x001C;

        [System.Runtime.InteropServices.DllImport("dwmapi.dll")]
        public static extern int DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS pMarInset);

        [System.Runtime.InteropServices.DllImport("dwmapi.dll")]
        public static extern int DwmSetWindowAttribute(IntPtr hwnd, int attr, ref int attrValue, int attrSize);

        [System.Runtime.InteropServices.DllImport("dwampi.dll")]
        public static extern int DwmIsCompoisionEnabled(ref int pfEnabled);

        [System.Runtime.InteropServices.DllImport("Gdi32.dll", EntryPoint = "CreateRoundRectRgn")]
        private static extern IntPtr CreateRoundRectRgn
        (
            int nLeftRect,
            int nTopRect,
            int nRightRect,
            int nBottomRect,
            int nWidthEllipse,
            int nHeightEllipse
        );

        public struct MARGINS
        {
            public int leftWidth;
            public int rightWidth;
            public int topHeight;
            public int bottomHeight;
        }

        protected override CreateParams CreateParams
        {
            get
            {
                m_aeroEnabled = CheckAeroEnabled();
                CreateParams cp = base.CreateParams;

                if (!m_aeroEnabled)
                    cp.ClassStyle |= CS_DROPSHADOW; return cp;
            }
        }

        private bool CheckAeroEnabled()
        {
            if (Environment.OSVersion.Version.Major >= 6)
            {
                int enabled = 0; DwmIsCompoisionEnabled(ref enabled);
                return (enabled == 1) ? true : false;
            }

            return false;
        }

        protected override void WndProc(ref Message m)
        {
            switch (m.Msg)
            {
                case WM_NCPAINT:
                    if (m_aeroEnabled)
                    {
                        var v = 2;
                        DwmSetWindowAttribute(this.Handle, 2, ref v, 4);
                        MARGINS margins = new MARGINS()
                        {
                            bottomHeight = 1,
                            leftWidth = 0,
                            rightWidth = 0,
                            topHeight = 0
                        }; DwmExtendFrameIntoClientArea(this.Handle, ref margins);
                    }
                    break;

                default: break;
            }

            base.WndProc(ref m);

            if (m.Msg == WM_NCHITTEST && (int)m.Result == HTCLIENT) 
                 m.Result = (IntPtr)HTCAPTION;
        }

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

Gradient_Sidebar_Panel.cs #

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Controls;
using System.Windows.Forms;

namespace Energy_Organizer
{
    internal class Gradient_Sidebar_Panel : System.Windows.Forms.Panel
    {
        public Color gradientTop {get; set;}
        public Color gradientBottom {get; set;}

        protected override void OnPaint(PaintEventArgs e)
        {
            LinearGradientBrush linear = new LinearGradientBrush(this.ClientRectangle, this.gradientTop, this.gradientBottom, 90F);
            Graphics graphics = e.Graphics;

            graphics.FillRectangle(linear, this.ClientRectangle);
            base.OnPaint(e);
        }
    }
}

错误截图 #

问题修复方案 #

你的错误源于两处拼写错误：

1. DLL文件名错误：[System.Runtime.InteropServices.DllImport("dwampi.dll")] 中，DLL名称应为dwmapi.dll（误写为dwampi），系统找不到不存在的DLL文件导致错误。
2. API方法名错误：DwmIsCompoisionEnabled方法名拼写错误，正确名称是DwmIsCompositionEnabled（单词Composition少了一个s）。

修正后的关键代码片段

// 修正DLL导入语句
[System.Runtime.InteropServices.DllImport("dwmapi.dll")]
public static extern int DwmIsCompositionEnabled(ref int pfEnabled);

// 修正CheckAeroEnabled方法中的调用
private bool CheckAeroEnabled()
{
    if (Environment.OSVersion.Version.Major >= 6)
    {
        int enabled = 0; 
        DwmIsCompositionEnabled(ref enabled);
        return enabled == 1;
    }
    return false;
}

修复完成后，清理项目并重新生成，运行程序即可解决该DLL错误。

内容的提问来源于stack exchange，提问作者Mr Ex