引用

///

/// 输入法切ENG
///

public void ChangeENG()
{
WinAPI.PostMessage(WinAPI.HWND_BROADCAST, WinAPI.WM_INPUTLANGCHANGEREQUEST, IntPtr.Zero, WinAPI.LoadKeyboardLayout(WinAPI.en_US, WinAPI.KLF_ACTIVATE));//输入法切换为ENGLISH,扫码枪需要
}
///

/// 输入法切Chinese
///

public void ChangeChinese()
{
WinAPI.PostMessage(WinAPI.HWND_BROADCAST, WinAPI.WM_INPUTLANGCHANGEREQUEST, IntPtr.Zero, WinAPI.LoadKeyboardLayout(WinAPI.cn_ZH, WinAPI.KLF_ACTIVATE));//输入法切换为Chinese
}

 

类：

///

/// 输入法切换
///

public class WinAPI
{
[DllImport("user32.dll")]
public static extern bool PostMessage(int hhwnd, uint msg, IntPtr wparam, IntPtr lparam);
[DllImport("user32.dll")]
public static extern IntPtr LoadKeyboardLayout(string pwszKLID, uint Flags);
public static uint WM_INPUTLANGCHANGEREQUEST = 0x0050;
public static int HWND_BROADCAST = 0xffff;
public static string en_US = "00000409"; //英文
public static string cn_ZH = "00000804";
public static uint KLF_ACTIVATE = 1;
}

C#中FormClosing与FormClosed的区别详细解析

C#中，当窗口关闭时，它会引发两个事件：Closing 和 Closed。

Closing 在窗口关闭之前引发，它提供一种机制，可以通过这种机制来阻止窗口关闭。 系统会向Closing 事件处理程序传递一个 FormClosingEventArgs e，该参数实现 Boolean Cancel 属性，将该属性设置为 true 可以阻止窗口关闭。

DialogResult result = MessageBox.Show("你确定要关闭吗！", "提示信息", MessageBoxButtons.OKCancel, MessageBoxIcon.Information);
if (result == DialogResult.OK)
{
CloseDevice();
ClosePLC();
GC.Collect();
//this.Close();
this.Dispose();
e.Cancel = false;

}
else
{
e.Cancel = true;
}

 

 

在窗口真正关闭之前，会引发 Closed，这时无法阻止窗口关闭。

private void Form1_FormClosed(object sender, FormClosingEventArgs e)
{
Application.Exit();
}