Visual C#.NET 追蹤與偵錯 (4)：完整程式碼清單、輸出結果與關鍵技巧總結

預期輸出 (Console + Output.txt)

The product name is Widget
The available units on hand are 100
The per unit cost is 1.03
Debug Information-Product Ending
Trace Information-Product Starting
The product name is Widget
Field: The product name is Widget
This message WILL appear
Trace Information-Product Ending

Output.txt 位於專案 \bin 目錄 (通常 C:\Documents and Settings\User\My Documents\Visual Studio Projects\conInfo\bin)。

完整程式碼 (conInfo 專案)

using System;
using System.Diagnostics;
using System.IO;

class Class1
{
    [STAThread]
    static void Main(string[] args)
    {
        string sProdName = "Widget";
        int iUnitQty = 100;
        double dUnitCost = 1.03;

        Debug.WriteLine("Debug Information-Product Starting ");
        Debug.Indent();
        Debug.WriteLine("The product name is " + sProdName);
        Debug.WriteLine("The available units on hand are " + iUnitQty);
        Debug.WriteLine("The per unit cost is " + dUnitCost);
        System.Xml.XmlDocument oxml = new System.Xml.XmlDocument();
        Debug.WriteLine(oxml);
        Debug.WriteLine("The product name is " + sProdName, "Field");
        Debug.WriteLine("The units on hand are " + iUnitQty, "Field");
        Debug.WriteLine("The per unit cost is " + dUnitCost, "Field");
        Debug.WriteLine("Total Cost is " + (iUnitQty * dUnitCost), "Calc");
        Debug.WriteLineIf(iUnitQty > 50, "This message WILL appear");
        Debug.WriteLineIf(iUnitQty < 50, "This message will NOT appear");
        Debug.Assert(dUnitCost > 1, "Message will NOT appear");
        Debug.Assert(dUnitCost < 1, "Message will appear since dUnitcost < 1 is false");

        TextWriterTraceListener tr1 = new TextWriterTraceListener(Console.Out);
        Debug.Listeners.Add(tr1);
        TextWriterTraceListener tr2 = new TextWriterTraceListener(File.CreateText("Output.txt"));
        Debug.Listeners.Add(tr2);

        Debug.WriteLine("The product name is " + sProdName);
        Debug.WriteLine("The available units on hand are " + iUnitQty);
        Debug.WriteLine("The per unit cost is " + dUnitCost);
        Debug.Unindent();
        Debug.WriteLine("Debug Information-Product Ending");
        Debug.Flush();

        Trace.WriteLine("Trace Information-Product Starting ");
        Trace.Indent();
        Trace.WriteLine("The product name is " + sProdName);
        Trace.WriteLine("The product name is " + sProdName, "Field");
        Trace.WriteLineIf(iUnitQty > 50, "This message WILL appear");
        Trace.Assert(dUnitCost > 1, "Message will NOT appear");
        Trace.Unindent();
        Trace.WriteLine("Trace Information-Product Ending");
        Trace.Flush();

        Console.ReadLine();
    }
}

關鍵技巧總結

• Debug / Trace 共用 WriteLine、WriteLineIf、Indent/Unindent、Assert、Flush。
• Indent/Unindent 讓輸出分組易讀。
• WriteLineIf 條件式輸出；Assert 條件為 false 才輸出。
• TextWriterTraceListener 導向 Console 與檔案雙通道。
• Flush() 確保緩衝區寫入完成。
• 須在專案屬性定義 DEBUG/TRACE 條件編譯符號才生效。