ListBox and ListBox

ListBox and ListBox
The Winfrom ListBox data source binding list interface is not updated. The problem is that the bound data source cannot be CRUD.

 

Scenario: Obtain the selected items of a listbox and add them to another listbox solution-1: do not directly bind DataSource first bind ListBox to BindingSource bs and bind bs to code case: 1-1: updatable add all

 private void btnAdd_Click(object sender, EventArgs e)     {     ListBox.SelectedObjectCollection selectObj = this.listLeft.SelectedItems;foreach (DataRowView item in selectObj){Sta sta = new Sta();sta.STCD = int.Parse(item.Row.ItemArray[0].ToString());sta.Name = item.Row.ItemArray[1].ToString();list.Add(sta);}BindingSource bs = new BindingSource();bs.DataSource = list;this.listRight.DataSource = bs;this.listRight.DisplayMember = "NAME";this.listRight.ValueMember = "STCD";     }

 

 

1-2: Remove duplicate items after modification

 

Private void btnAdd_Click (object sender, EventArgs e) {ListBox. selectedObjectCollection selectObj = this. listLeft. selectedItems; foreach (DataRowView item in selectObj) {bool B = true; // to check whether the listright item already exists, do not add foreach (Model. sta rightItem in this. listRight. items) {if (rightItem. name = item. row. itemArray [1]. toString () {B = false ;}} if (B) {Sta sta = new Sta (); sta. STCD = int. parse (item. row. itemArray [0]. toString (); sta. name = item. row. itemArray [1]. toString (); list. add (sta) ;}} BindingSource bs = new BindingSource (); bs. dataSource = list; this. listRight. dataSource = bs; this. listRight. displayMember = "NAME"; this. listRight. valueMember = "STCD ";}

1-3: After setting the DataSource attribute, the item set cannot be modified and can only be bound to the list set. I don't know if there is a good solution, the root cause is that data sources cannot be used to bind data. Only the final version 0.0 of item 1-4 can be directly added.

# Add listboxitemsListBox to the right of region. selectedObjectCollection selectObj = this. listLeft. selectedItems; foreach (Model. sta item in selectObj) {bool B = true; // if you want to check whether this item already exists in listright, no foreach (Model is added. sta rightItem in this. listRight. items) {if (rightItem. name = item. name) {B = false ;}}if (B) {Sta sta = new Sta (); sta. STCD = item. STCD; sta. name = item. name; this. listRight. items. add (sta) ;}} this. listRight. displayMember = "NAME"; this. listRight. valueMember = "STCD"; # endregion // Delete the added item on the left // 1-2: remove the selected item int icount = listLeft. selectedItems. count; for (int I = 0; I <icount; I ++) {this. listLeft. items. remove (listLeft. selectedItems [icount-1-I]);}

 

In C #, there are several listbox problems ,,,

Add one row of listbox1 to another
Add a textbox to set the number of rows and convert the data type.
Then extract it using lines [line n ].
The following is the code that the landlord previously asked for. If the code is correct, I will reference it (saving the keyboard)

Read the txt file row by row and add it to listbox1:
Private void button3_Click (object sender, EventArgs e)
{
StreamReader file = new StreamReader (@ "c: \ IP.txt", System. Text. Encoding. Default );
String s = "";
While (s! = Null)
{
S = file. ReadLine ();
If (s! = Null &&! S. Equals (""))
ListBox1.Items. Add (s );
}
File. Close ();
}

Add the value in listbox1 to listbox2:
Private void button4_Click (object sender, EventArgs e)
{
If (listBox1.Items. Count> 0 & listBox1.SelectedItem! = Null)
{
ListBox2.Items. Add (listBox1.SelectedItem );
}
}

C # listBox Problems

Private void button3_Click (object sender, EventArgs e)
{
If (listBox1.SelectedIndex <listBox1.Items. Count-1) // <=== = this sentence is compared. The error is found here.
ListBox1.SelectedIndex = (listBox1.SelectedIndex + 1 );
Else if (listBox1.Items. Count> 0)
ListBox1.SelectedIndex = 0;
PlaySong (listBox1.SelectedIndex + 1 );
}

//-----------------------
// When the form size is changed, the listbox size is also changed.
Private void Form1_Resize (object sender, EventArgs e)
{
ListBox1.Top = 0;
ListBox1.Left = 0;
ListBox1.Width = this. Width-5; // <= this value is changed as required.
ListBox1.Height = this. Height-10; // <= this value is changed as required.
}