public class StringEventArgs : EventArgs  //要继承EventArgs  
{
public StringEventArgs(string aStrValue)
{
StrValue = http://www.mamicode.com/aStrValue;
}

public string StrValue { get; set; }
}

public virtual event EventHandler<StringEventArgs> OnEditValueChanged;

string a=1;

OnEditValueChanged(aSender, new StringEventArgs(a));

方法间多参数传递