Question

我是C＃的新手，我遇到了两个错误。我从这里得到了这段代码，并把它放在我的应用程序中。我已经尝试更换鼠标功能，但从未成功，我不确定是否 public static extern void mouse_event位于正确的位置。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace WindowsFormsApplication2
{


    public partial class Form1 : Form
    {
        [System.Runtime.InteropServices.DllImport("user32.dll")]
        public static extern void mouse_event(int dwFlags, int dx, int dy, int cButtons, int dwExtraInfo);

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void button2_Click(object sender, EventArgs e)
        { //Here it expects "}"

            public const int MOUSEEVENTF_LEFTDOWN = 0x02;
            public const int MOUSEEVENTF_LEFTUP = 0x04;
            public const int MOUSEEVENTF_RIGHTDOWN = 0x08;
            public const int MOUSEEVENTF_RIGHTUP = 0x10;

            public void MouseClick()
            {
                int x = 100;
                int y = 100;
                mouse_event(MOUSEEVENTF_LEFTDOWN, x, y, 0, 0);
                mouse_event(MOUSEEVENTF_LEFTUP, x, y, 0, 0);
            }
        }
    }
}//Here the error is "type or namespace definition, or end-of-file expected

Answer 1

由于您在}之后编写了public const int MOUSEEVENTF_LEFTDOWN = 0x02;，并且{关键字无法在方法正文中显示，因此预计会public。局部常数是......好的......本地的，不是公共的。

对于MouseClick，您不能使用此语法在方法内编写方法，您只能编写lambdas和内联委托。

你的意思是？

private void button2_Click(object sender, EventArgs e)
{
    const int MOUSEEVENTF_LEFTDOWN = 0x02;
    const int MOUSEEVENTF_LEFTUP = 0x04;
    const int MOUSEEVENTF_RIGHTDOWN = 0x08;
    const int MOUSEEVENTF_RIGHTUP = 0x10;

    int x = 100;
    int y = 100;
    mouse_event(MOUSEEVENTF_LEFTDOWN, x, y, 0, 0);
    mouse_event(MOUSEEVENTF_LEFTUP, x, y, 0, 0);
}

或者是这个？

private void button2_Click(object sender, EventArgs e)
{
    MouseClick();
}

public const int MOUSEEVENTF_LEFTDOWN = 0x02;
public const int MOUSEEVENTF_LEFTUP = 0x04;
public const int MOUSEEVENTF_RIGHTDOWN = 0x08;
public const int MOUSEEVENTF_RIGHTUP = 0x10;

public void MouseClick()
{
    int x = 100;
    int y = 100;
    mouse_event(MOUSEEVENTF_LEFTDOWN, x, y, 0, 0);
    mouse_event(MOUSEEVENTF_LEFTUP, x, y, 0, 0);
}

Answer 2

问题1：
您无法在方法

中声明public const个字段

private void button2_Click(object sender, EventArgs e)
{ //Here it expects "}"
    public const int MOUSEEVENTF_LEFTDOWN = 0x02; //error

Access modifiers（public，private ...）是用于指定成员或类型的已声明可访问性的关键字，它们不应在方法内使用。在const定义之前删除public关键字将解决问题。如果要从类中的其他方法或从类外部访问常量，则应将它们移到类中。

问题2：
您正在另一个方法中定义一个方法，但您不允许这样做。 MouseClick在button2_Click内声明，这是不合法的。

尝试将您的代码更改为此

public const int MOUSEEVENTF_LEFTDOWN = 0x02;
public const int MOUSEEVENTF_LEFTUP = 0x04;
public const int MOUSEEVENTF_RIGHTDOWN = 0x08;
public const int MOUSEEVENTF_RIGHTUP = 0x10;

private void button2_Click(object sender, EventArgs e)
{ 
    MouseClick();
}

public void MouseClick()
{
    int x = 100;
    int y = 100;
    mouse_event(MOUSEEVENTF_LEFTDOWN, x, y, 0, 0);
    mouse_event(MOUSEEVENTF_LEFTUP, x, y, 0, 0);
}

Answer 3

您必须将MouseClick方法和常量声明移到Form1类的范围内：

public partial class Form1 : Form
{
    [System.Runtime.InteropServices.DllImport("user32.dll")]
    public static extern void mouse_event(int dwFlags, int dx, int dy, int cButtons, int dwExtraInfo);

    public Form1()
    {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {

    }

    public const int MOUSEEVENTF_LEFTDOWN = 0x02;
    public const int MOUSEEVENTF_LEFTUP = 0x04;
    public const int MOUSEEVENTF_RIGHTDOWN = 0x08;
    public const int MOUSEEVENTF_RIGHTUP = 0x10;

    public void MouseClick()
    {
        int x = 100;
        int y = 100;
        mouse_event(MOUSEEVENTF_LEFTDOWN, x, y, 0, 0);
        mouse_event(MOUSEEVENTF_LEFTUP, x, y, 0, 0);
    }

    private void button2_Click(object sender, EventArgs e)
    { //Here it expects "}"
        MouseClick();
    }
}

“}期望”它不应该

3 个答案: