3
我目前有一個類，它使用KeyValuePair和List以Key = track，Value = artist的格式存儲軌道集合。從列表返回一個匹配<KeyValuePair <string，string >>
我試圖提供一種搜索特定曲目的方法，如果有任何匹配，則返回整個匹配的CD。
這是迄今爲止我嘗試：
public CompilationCD FindTrackInComCD(string track)
{
CompilationCD temp = new CompilationCD();
List<CD> tempComCols = _cdCollection.FindAll(delegate(CD cd)
{ return cd.GetType() == temp.GetType(); });
foreach (KeyValuePair<string, string> comCD in tempComCols)
{
if (comCD.Key.Contains(track))
{
return comCD;
}
}
throw new ArgumentException("No matches found");
}
我的CD型CD（List<CD>）的集合，因此，我通過比較臨時列表創建此時，相應類型的新List<>。
編譯時我收到以下錯誤：
Cannot convert type 'CDCollection.CD' to System.Collections.Generic.KeyValuePair<string,string>'
Cannot implicitly convert type 'System.Collections.Generic.KeyValuePair<string,string>'
（CDCollection是我的項目命名空間和CD/CompilationCD是類）
對不起，這似乎像一個類似的問題，一個我已經以前問過。我試圖使用之前給出的方法，但我有點難過;我經常沒有使用List<>或KeyValuePair。
這是CD類：
using System;
System.Collections中使用; using System.Collections.Generic;使用System.Linq的 ; using System.Text;
命名空間CDCollection { 公共類CD { ＃地區字段 私人只讀字符串_artist; private readonly string _album; private List _track = new List（）; #endregion
#region Constructors
public CD()
{
_artist = "";
_album = "";
_track = null;
}
public CD(string albumName)
{
_album = albumName;
}
public CD(string artistName, string albumName)
{
_artist = artistName;
_album = albumName;
}
#endregion
#region Properties
/// <summary>
/// Get/Set Artist Name
/// </summary>
public virtual string Artist
{
get
{
return _artist;
}
set
{
value = _artist;
}
}
/// <summary>
/// Get/Set Album
/// </summary>
public string Album
{
get
{
return _album;
}
set
{
value = _album;
}
}
/// <summary>
/// Get/Set Track Name
/// </summary>
public virtual List<string> Track
{
get
{
return _track;
}
set
{
value = _track;
}
}
#endregion
#region ToString()
/// <summary>
/// Custom ToString() Method
/// </summary>
/// <returns></returns>
public override string ToString()
{
//Create new StringBuilder object
StringBuilder sb = new StringBuilder();
sb.Append("Artist Name");
//Display error if Artist is not available
if (_artist == null || _artist == "")
{
sb.Append("\nNo Artist Entered");
}
else
{
sb.Append("\n" + this._artist);
}
sb.Append("\n");
sb.Append("\nAlbum Name");
//Display error if Album is not available
if (_album == null || _album == "")
{
sb.Append("\nNo Album Entered");
}
else
{
sb.Append("\n" + this._album);
}
sb.Append("\n");
sb.Append("\nTrack Name");
sb.Append("\n");
//Iterate through all tracks stored in list
foreach (string trackName in _track)
{
//Print each artist
sb.Append("\n" + trackName);
}
sb.Append("\nEnd of CD Record.........");
return sb.ToString();
}
#endregion
}
}
這是CompilationCD類：
using System;
使用System.Collections.Generic;使用System.Linq的 ; using System.Text;
命名空間CDCollection { 公共類CompilationCD：CD { ＃地區字段
private readonly string _artist;
private readonly string _album;
private List<KeyValuePair<string,string>> _tracks = new List<KeyValuePair<string,string>>();
//List<KeyValuePair> Reference.
//http://msdn.microsoft.com/en-us/library/6sh2ey19(VS.85).aspx
#endregion
#region Constructors
public CompilationCD()
{
_album = "";
_artist = "Various Artists";
}
public CompilationCD(string albumName):base(albumName)
{
_album = albumName;
_artist = "Various Artists";
}
#endregion
public void AddTracks(string track, string artist)
{
_tracks.Add(new KeyValuePair<string, string>(track, artist));
}
#region Properties
public override string Artist
{
get
{
return this._artist;
}
}
public new List<KeyValuePair<string,string>> Track
{
get
{
return _tracks;
}
set
{
_tracks = value;
}
}
#endregion
#region ToString()
//TEST
public override string ToString()
{
//Create new StringBuilder object
StringBuilder sb = new StringBuilder();
sb.Append("Artist Name");
//Display error if Artist is not available
if (_artist == null || _artist == "")
{
sb.Append("\nNo Artist Entered");
}
else
{
sb.Append("\n" + this._artist);
}
sb.Append("\n");
sb.Append("\nAlbum Name");
//Display error if Album is not available
if (base.Album == null || base.Album == "")
{
sb.Append("\nNo Album Entered");
}
else
{
sb.Append("\n" + base.Album);
}
sb.Append("\n");
sb.Append("\nTrack Name");
sb.Append("\n");
////Iterate through all tracks stored in list
//foreach (string trackName in base.Track)
//{
// //Print each artist
// sb.Append("\n" + trackName);
//}
for(int i = 0; i <= _tracks.Count; i++)
{
string track = _tracks[i].Key;
string artist = _tracks[i].Value;
sb.Append("\nTrack");
sb.Append(track);
sb.Append("\nArtist");
sb.Append(artist);
}
sb.Append("\nEnd of Compilation CD Record.........");
return sb.ToString();
}
#endregion
}
}
我有嚴格的規定，這意味着我必須從CD繼承創建我CompilationCD以及因爲使用列表>我的曲目集合，它需要同時擁有曲目和藝術家。瘋狂我知道=/
此外，我必須存儲CD類型列表中的所有類型的CD（列表）。
您應該考慮使用運算符'is'而不是比較'GetType（）'的返回值。它既快又短，並且在擴展性方面表現更好（例如，如果你以後從'CompilationCD'派生出一些類）。 – 2009-11-24 23:04:35