//设置“搜狗拼音”为当前输入法
      foreach (InputLanguage item in InputLanguage.InstalledInputLanguages)
      {
        if (item.LayoutName.Contains("搜狗拼音"))
        {
          InputLanguage.CurrentInputLanguage = item;
          break;
        }
      }
      //设置“智能 ABC”为当前输入法
      foreach (InputLanguage item in InputLanguage.InstalledInputLanguages)
      {
        if (item.LayoutName.Contains("智能 ABC"))
        {
          InputLanguage.CurrentInputLanguage = item;
          break;
        }
      }
      //设置系统默认输入法为当前输入法
      InputLanguage.CurrentInputLanguage = InputLanguage.DefaultInputLanguage;

    private delegate void fixImeDele();
    private fixImeDele _fixime;

      fixime = delegate
      {
        IntPtr HIme = ImmGetContext(this.Handle);
        ImmSetOpenStatus(HIme, true);
      };

this.BeginInvoke(fixime);

  public partial class Form1 : Form
  {
    [DllImport("imm32.dll")]
    public static extern IntPtr ImmGetContext(IntPtr hwnd);//获取当前正在输入的窗口的输入法句柄
    [DllImport("imm32.dll")]
    public static extern bool ImmSetOpenStatus(IntPtr himc, bool b);//设置输入法的状态
    private delegate void fixImeDele();
    private fixImeDele fixime;
    public Form1()
    {
      InitializeComponent();
    }
    private void txt搜狗拼音_Enter(object sender, EventArgs e)
    {
      //int index = InputLanguage.InstalledInputLanguages.IndexOf(InputLanguage.CurrentInputLanguage);
      //设置“搜狗拼音”为当前输入法
      foreach (InputLanguage item in InputLanguage.InstalledInputLanguages)
      {
        if (item.LayoutName.Contains("搜狗拼音"))
        {
          InputLanguage.CurrentInputLanguage = item;
          break;
        }
      }
    }
    private void textBox3_Enter(object sender, EventArgs e)
    {
      //设置“智能 ABC”为当前输入法
      foreach (InputLanguage item in InputLanguage.InstalledInputLanguages)
      {
        if (item.LayoutName.Contains("智能 ABC"))
        {
          InputLanguage.CurrentInputLanguage = item;
          break;
        }
      }
    }
    private void txt系统默认_Enter(object sender, EventArgs e)
    {
      //设置系统默认输入法为当前输入法
      InputLanguage.CurrentInputLanguage = InputLanguage.DefaultInputLanguage;
    }
    private void txtTrue_Enter(object sender, EventArgs e)
    {
      fixime = delegate
      {
        IntPtr HIme = ImmGetContext(this.Handle);
        ImmSetOpenStatus(HIme, true);
      };
      this.BeginInvoke(fixime);
    }
    private void txtFalse_Enter(object sender, EventArgs e)
    {
      fixime = delegate
      {
        IntPtr HIme = ImmGetContext(this.Handle);
        ImmSetOpenStatus(HIme, false);
      };
      this.BeginInvoke(fixime);
    }
  }

this.ImeMode = System.Windows.Forms.ImeMode.On;

this.ImeMode = System.Windows.Forms.ImeMode.OnHalf;