我和我的朋友一直在做一个游戏，我们设置了一个跟踪监听器，这里是一些代码：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
namespace GuiGame {
/// <summary>
/// A type of Trace Listener that sends its output to a ListBox.
/// </summary>
public class ListBoxTraceListener : TraceListener {
private ListBox listBox; // A reference to the listbox that we're writing to.
private string stringToAddToListBox = "";
private const char NEW_LINE = '\n';
/// <summary>
/// Parameterless constructor.
/// Do not want the generic default constructor to be used
/// as there is no way to set the ListBoxTraceListener's data.
/// This replaces the compiler's generic default constructor.
/// Pre: none
/// Post: ALWAYS throws an ArgumentException.
/// </summary>
/// <remarks>NOT TO BE USED!</remarks>
public ListBoxTraceListener() {
throw new ArgumentException("Parameterless constructor invalid.");
} // end ListBoxTraceListener constructor
/// <summary>
/// Constructor with initialising parameters.
/// Pre: the existence of a ListBox on a GUI form.
/// Post: initialised object.
/// </summary>
/// <param name="listBox">The ListBox that we're writing to.</param>
public ListBoxTraceListener(ListBox listBox) {
this.listBox = listBox;
}
/// <summary>
/// Automatically collects the outputs from all Trace.WriteLine statements.
/// Pre: none.
/// Post: the string s is displayed in the listBox.
/// </summary>
/// <param name="s"></param>
public override void WriteLine(string s) {
Write(s + NEW_LINE);
} //end WriteLine
/// <summary>
/// Automatically collects the outputs from all Trace.Write statements.
/// Pre: none.
/// Post: the string s is displayed in the listBox, once we receive a NEW_LINE.
/// </summary>
/// <param name="s"></param>
public override void Write(string s) {
stringToAddToListBox += s;
// If we have one or more complete lines
if (stringToAddToListBox.Contains (NEW_LINE)) {
// Split the string into multiple lines.
// If NEW_LINE is found at the beginning or end of the string,
// then the corresponding array element contains an empty string.
string[] lines = stringToAddToListBox.Split(NEW_LINE);
// Add all the lines to the listbox, except for the last one.
// When stringToAddToListBox has a new-line at the end,
// the last element in lines[] will be an empty string.
int highestLineNumber = lines.Length - 1;
for (int i = 0; i < highestLineNumber; i++) {
AddToListBox(lines[i]);
}
// Reset stringToAddToListBox to what remains. (May be an empty string).
stringToAddToListBox = lines[highestLineNumber];
}
} // end Write
/// <summary>
/// Adds a complete output-line to the ListBox.
/// Pre: none.
/// Post: the string listBoxLine is displayed in the listBox .
/// </summary>
/// <param name="listBoxLine"></param>
private void AddToListBox(string listBoxLine) {
Debug.Assert(listBox != null, "listBox != null");
listBox.Items.Add(listBoxLine);
} // end AddToListBox
}
}
在这个阶段，我们只是尝试使用跟踪侦听器在其中输出一些文本，ListBox所以我们知道它正在工作，所以我们有一个事件处理程序设置：
private void RollDiceButton_Click(object sender, EventArgs e)
{
}
我们无法从跟踪侦听器获得任何输出。Add没有为此设置作为跟踪侦听器的方法。任何人都可以提供一些建议吗？我想也许我们正在做一些我们错过的非常愚蠢和明显的事情。