C# 無限級分類的實現
2024-09-07 17:05:16
供稿：網友
數據庫表：CategoryInfo
字段名 類型
ciID int //記錄序號，自增量
ciName nvarchar(20) //分類名
ciParent int //父分類序號
ciLayer int //所處的層次
ciDescription nvarchar(200) //對分類的描述
分類的類設計
public class CategoryInfo
{
private int ciID;//分類ID
private string ciName;//分類名
private int ciParent;//分類的父分類ID
private string ciDescription;//分類描述
private int ciLayer;//分類所屬層次
//構造函數
public CategoryInfo() { }
public CategoryInfo(int cID, string cName, int cParent, string cDescription, int cLayer)
{
this.ciID = cID;
this.ciName = cName;
this.ciParent = cParent;
this.ciDescription = cDescription;
this.ciLayer = cLayer;
}
//屬性
public int CategoryID
{
get{ return ciID;}
set { ciID = value;}
}
public string CategoryName
{
get{ return ciName;}
set { ciName = value; }
}
public int CategoryParent
{
get{ return ciParent;}
set { ciParent = value; }
}
public string CategoryDescription
{
get { return ciDescription; }
set { ciDescription = value; }
}
public int CategoryLayer
{
get { return ciLayer; }
set { ciLayer = value; }
}
}
獲取子分類的存儲過程
CREATE PROCEDURE [dbo].[category_getChild]
@cName nvarchar(20)
AS
BEGIN
DECLARE @tmpID int
SELECT @tmpID=ciID FROM CategoryInfo
WHERE RTRIM(ciName) = RTRIM(@cName)
if(@tmpID IS NOT NULL)
SELECT * FROM CategoryInfo
WHERE ciParent = @tmpID
ORDER BY ciLayer
END
獲取子分類的函數
public IList<CategoryInfo> GetChildCategories(IList<CategoryInfo> cInfos,string cName)
{
SqlConnection con = new SqlConnection(connectionString);
SqlCommand cmd = new SqlCommand("category_getChild", con);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add(new SqlParameter(PARAM_CNAME, SqlDbType.NVarChar, 20));
cmd.Parameters[PARAM_CNAME].Value = cName;
IList<string> tmpNames = new List<string>(); //臨時存儲獲取的子
try
{
con.Open();
SqlDataReader reader = cmd.ExecuteReader();
if (reader.HasRows)
{
while (reader.Read())
{
CategoryInfo cInfo = new CategoryInfo(
(int)reader["ciID"],
reader["ciName"].ToString(),
(int)reader["ciParent"],
reader["ciDescription"].ToString(),
(int)reader["ciLayer"]
);
string tmpName = reader["ciName"].ToString();
cInfos.Add(cInfo);//添加獲取到的分類到cInfos
tmpNames.Add(tmpName);//添加獲取到的子分類名到tmpNames
}
}
}
catch
{
throw new ApplicationException("獲取分類出錯!");
}
finally
{
con.Close();
}
foreach(string c in tmpNames)
{
cInfos = GetChildCategories(cInfos,c); //遞歸運算。繼續獲取子分類
}
return cInfos;
}
說明：在該函數中，tmpNames如果換成是IList<CategoryInfo>,即它添加的元素與cInfos是一樣的時，如果要移除其中的一項，則cInfos中會同時移除一項。因為CategoryInfo是類，是引用類型的，而非值類型。所以tmpNames采用了string類型，以避免這個問題。
