我想在我的列表中添加一个对象，但嵌套循环的组织方式使这成为不可能(C#)
本文关键字：方式使 不可能 嵌套循环 列表 我的 添加 一个对象 | 更新日期: 2023-09-27 18:28:49
所以我正在制作一个程序，它有几个类别，其中存储了多个注释。我是一名学生，我们得到了使用SQL server的localdb来保存我们的类别和注释的任务。程序使用树状视图控件显示类别和注释。
现在我正试图为我的笔记制作一个搜索栏。它必须过滤笔记的标题。
我的问题是，如何从一个类别中获取所有笔记，并将它们添加到同一类别中？现在，所有笔记都显示在不同的类别中，但名称相同。这是因为我的主循环处理注释，而内部循环处理类别。
当我把"categoriesUI1.Categories.Add（category）；"放在while循环后面时，我只看到一个类别有一个音符，因为音符的while循环是先处理的。
下面是一些额外的屏幕截图，让你更好地了解我的程序是如何工作的：
过滤前：https://gyazo.com/cea5c4d9ff18fb93c9f47cf336942bc9
在"test2"上筛选后：https://gyazo.com/282240e5f1a754389688c68257893d92
connection = new SqlConnection(@"Data Source=(localdb)'mssqllocaldb;Initial Catalog=dbNotes;Integrated Security=True;MultipleActiveResultSets=true");
categoriesUI1.tvwCategories.SelectedNode = categoriesUI1.tvwCategories.TopNode;
int count = categoriesUI1.Categories.Count;
if (count > 0)
{
for (int i = count; i > 0; i = count)
{
categoriesUI1.Categories.RemoveAt(0);
count = categoriesUI1.Categories.Count;
}
}
connection.Open();
SqlCommand commandNote = new SqlCommand("SELECT ID, Cat_ID, Titel, Text, Created FROM tblNote WHERE Titel LIKE '%" + searchBarUI1.getTextValue() + "%'", connection);
SqlDataReader readerNote = commandNote.ExecuteReader();
if (readerNote.HasRows)
{
Category category = new Category();
while (readerNote.Read())
{
int id = readerNote.GetInt32(0);
int Cat_id = readerNote.GetInt32(1);
string title = readerNote.GetString(2);
string text = readerNote.GetString(3);
DateTime created = readerNote.GetDateTime(4);
string Cat_title = "";
SqlCommand commandCategory = new SqlCommand("SELECT Titel FROM tblCategory WHERE ID = " + Cat_id, connection);
SqlDataReader readerCategory = commandCategory.ExecuteReader();
if (readerCategory.HasRows)
{
while (readerCategory.Read())
{
Cat_title = readerCategory.GetString(0);
category = new Category(Cat_id, Cat_title);
}
}
Note note;
note = new Note(id, title, text, created);
category.Notes.Add(note);
readerCategory.Close();
categoriesUI1.Categories.Add(category);
}
}
readerNote.Close();
connection.Close();
我给了你我的idae
1.您可以通过Searchkey获得所有Cates。2.get Add all Notes filed by searchKey and Cat_id，Add they to proper Cate
细节如下，只是一些想法，尚未测试。希望它能有所帮助。
/// <summary>
/// initail your UI
/// </summary>
void ini()
{
connection = new SqlConnection(@"Data Source=(localdb)'mssqllocaldb;Initial Catalog=dbNotes;Integrated Security=True;MultipleActiveResultSets=true");
categoriesUI1.tvwCategories.SelectedNode = categoriesUI1.tvwCategories.TopNode;
int count = categoriesUI1.Categories.Count;
if (count > 0)
{
for (int i = count; i > 0; i = count)
{
categoriesUI1.Categories.RemoveAt(0);
count = categoriesUI1.Categories.Count;
}
}
}
/// <summary>
/// this is for add all searchressult Cates to to Treeview
/// </summary>
/// <param name="sKey"></param>
void SearchCate(string sKey)
{
connection.Open();
SqlCommand commandCategory = new SqlCommand("SELECT Titel FROM tblCategory WHERE ID in (
SELECT ID FROM tblNote WHERE Titel LIKE '%" + sKey +
"%') " + Cat_id, connection);
SqlDataReader readerCategory = commandCategory.ExecuteReader();
if (readerCategory.HasRows)
{
while (readerCategory.Read())
{
Cat_title = readerCategory.GetString(0);
category = new Category(Cat_id, Cat_title); // new category
categoriesUI1.Categories.Add(category);
// then add your note's search result here to eavcgorhe
AddNoteToACateBySearchKey(sKey,category);
}
}
}
/// <summary>
/// add all searchresult note to cate
/// </summary>
/// <param name="sKey"></param>
/// <param name="Parent"></param>
void AddNoteToACateBySearchKey(string sKey, Category Parent )
{
connection.Open();
SqlCommand commandNote = new SqlCommand("SELECT ID, Cat_ID, Titel, Text, Created FROM tblNote WHERE Titel LIKE '%" + sKey + "%' and Cat_ID='" + Parent.Cat_id + "' ", connection);
SqlDataReader readerNote = commandNote.ExecuteReader();
if (readerNote.HasRows)
{
Category category = new Category();
while (readerNote.Read())
{
int id = readerNote.GetInt32(0);
int Cat_id = readerNote.GetInt32(1);
string title = readerNote.GetString(2);
string text = readerNote.GetString(3);
DateTime created = readerNote.GetDateTime(4);
string Cat_title = "";
Note note;
note = new Note(id, title, text, created); // new note
category.Notes.Add(note);
readerCategory.Close();
}
}
readerNote.Close();
connection.Close();
}
只有当Cat_ID与当前类别的ID对应时，我才添加一个注释来修复它。现在，主循环处理类别，内部循环处理注释。
connection = new SqlConnection(@"Data Source=(localdb)'mssqllocaldb;Initial Catalog=dbNotes;Integrated Security=True;MultipleActiveResultSets=true");
categoriesUI1.tvwCategories.SelectedNode = categoriesUI1.tvwCategories.TopNode;
int count = categoriesUI1.Categories.Count;
if (count > 0)
{
for (int i = count; i > 0; i = count)
{
categoriesUI1.Categories.RemoveAt(0);
count = categoriesUI1.Categories.Count;
}
}
connection.Open();
SqlCommand commandCategory = new SqlCommand("SELECT ID, Titel from tblCategory", connection);
SqlDataReader readerCategory = commandCategory.ExecuteReader();
if (readerCategory.HasRows)
{
while (readerCategory.Read())
{
int id = readerCategory.GetInt32(0);
string titel = readerCategory.GetString(1);
Category category = new Category(id, titel);
SqlCommand commandNote = new SqlCommand("SELECT ID, Cat_ID, Titel, Text, Created FROM tblNote WHERE Titel LIKE '%" + searchBarUI1.getTextValue() + "%'", connection);
SqlDataReader readerNote = commandNote.ExecuteReader();
if (readerNote.HasRows)
{
while (readerNote.Read())
{
int catID = readerNote.GetInt32(1);
if (catID == id)
{
int noteID = readerNote.GetInt32(0);
string noteTitel = readerNote.GetString(2);
string noteText = readerNote.GetString(3);
DateTime noteCreated = readerNote.GetDateTime(4);
Note note = new Note(noteID, noteTitel, noteText, noteCreated);
category.Notes.Add(note);
}
}
}
if(category.Notes.Count > 0)
categoriesUI1.Categories.Add(category);
}
}