像Checked
, Visible
,Enabled
或这样的属性Supported
不能通过VSCT
文件定义。您需要一个控制命令状态的命令处理程序。我创建了一个基类,它包装了OleMenuCommand
实例的创建并处理命令BeforeQueryStatus
事件。这是我的实现的精简版本,但它会给你一个想法如何解决它......
internal abstract class CommandHandler : IDisposable
{
private readonly OleMenuCommand command;
protected CommandHandler(Guid group, int id)
{
var commandid = CommandID(group, id);
this.command = new OleMenuCommand(this.Invoke, commandId);
this.command.BeforeQueryStatus += this.OnBeforeQueryStatus;
}
protected virtual void OnExecute() { }
protected virtual void OnQueryStatus(QueryStatusEventArgs e) { }
private void Invoke(object sender, EventArgs e)
{
this.OnExecute();
}
private void OnBeforeQueryStatus(object sender, EventArgs e)
{
OleMenuCommand command;
if ((command = sender as OleMenuCommand) != null)
{
var e = new QueryCommandEventArgs
{
Checked = command.Checked,
}
this.OnQueryStatus(e);
command.Checked = e.Checked;
}
}
public void Dispose()
{
this.command.BeforeQueryStatus -= this.OnBeforeQueryStatus;
}
}
public class QueryCommandEventArgs : EventArgs
{
public bool Checked { get; set; }
}
该类CommandHandler
允许控制任何菜单命令的状态。只需从中派生新的处理程序实现并覆盖OnExecute
andOnQueryStatus
方法,例如...
internal sealed class MyCommand : CommandHandler
{
private bool checked;
public MyCommand() : base(GuidCmdSet, MyCommandId) { }
protected override void OnExecute()
{
this.checked = !this.checked; // toggle checked state
}
protected override void OnQueryStatus(QueryStatusEventArgs e)
{
e.Checked = this.checked;
}
}