Home / Questions / 8308
Accepted
Fran Pino
Asked: 2020-04-23 03:46:48 +0800 CST 2020-04-23 03:46:48 +0800 CST

Loop through a ListBox and put its items into an array

  • 772

I fill a list from a OpenFileDialogand put it in "file" and then put it in the list like this:

foreach (string file in selectedFiles)
{
    ListBoxItem lstItem = new ListBoxItem();
    lstItem.Content = file; //File es la cadena de la URL
    miLista.Items.Add(lstItem);
}

What I assign to the ListBoxare URLtype

c:\user\paco\image1.jpg

c:\user\paco\image2.jpg

So far so good, but now I need to loop through that ListBoxand put its Items into aString[]

String[] matriz = new String[miLista.Items.Count];
foreach (Object index in miLista.Items)
{
    matriz = index.ToString().Split();
}

In this way, what gets me in each index of the string[]is the following:

System.Windows.Controls.ListBoxItem: c:\user\cucumber\image1.jpg System.Windows.Controls.ListBoxItem: c:\user\cucumber\image2.jpg System.Windows.Controls.ListBoxItem: c:\user\cucumber \image3.jpg

What I need is only the URLand that it does not return the Type and the Value, I need to put String[]only the value in it.

I fill the ListBoxlike this:

OpenFileDialog myFD = new OpenFileDialog();
myFD.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.MyPictures);
myFD.Multiselect = true;
myFD.Title = "Seleccione uno o más archivos";
myFD.Filter = "Archivos imagen (*.jpg),(*.jpeg),(*.gif),(*.png)|*.jpg;*.jpeg;*.gif;*.png";

Nullable<bool> result = myFD.ShowDialog();
if (result == true)
{
    string[] selectedFiles = myFD.FileNames; // La propiedad FileNames (o FileName) almacena la ruta, nombre y extensión.
    foreach (string file in selectedFiles)
    {
        miLista.Items.Add(file);               
    }
    archivo.set_listaReproduccion(selectedFiles);
    archivo.grabar();
}
c#

2 Answers

  1. Best Answer

    The problem you have is in this piece of code:

    foreach (string file in selectedFiles)
{
    ListBoxItem lstItem = new ListBoxItem();
    lstItem.Content = file; //File es la cadena de la URL
    //aqui estas agregando un ListBoxItem a Items cuando solo deberías agregar file
    miLista.Items.Add(lstItem); 
}

    One solution would be to replace this line and use the suggestions we gave you earlier:

     miLista.Items.Add(lstItem);

    By

     miLista.Items.Add(file);

    But if you need it lstItemto stay in the collection listbox.Itemsthen all you have to do is cast.

    String[] matriz = new String[miLista.Items.Count];
for (int i = 0; i < miLista.Items.Count; i++)
{
    ListBoxItem item = miLista.Items[i] as ListBoxItem;
    if(item!= null)
    {
        //suponiendo que content es un string
        matriz[i] = miLista.Items[i].Content;
    }

}

    Assuming you load your listbox like this, you shouldn't have any casting problems:

        private void button1_Click(object sender, EventArgs e)
    {
        if (openFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
        {
            foreach (var item in openFileDialog1.FileNames)
            {
                listBox1.Items.Add(item);
            }
        }

        String[] matriz = new String[listBox1.Items.Count];

        listBox1.Items.CopyTo(matriz, 0);
    }

    Note that FileNamesit is already a String[]practically you do not need to do neither the copynor the foronly assign it:

    String[] matriz = openfiledialog.Filenames;

    But anyway I'm going to leave below ways to do it so it can be useful to other people.

    The simplest option is:

    listBox1.Items.CopyTo(matriz, 0);

    But you can also do it using a loop forinstead of theforeach

    String[] matriz = new String[miLista.Items.Count];
for (int i = 0; i < listBox1.Items.Count; i++)
{
    matriz[i] = listBox1.Items[i].ToString();
}
    • 4

  2. You can try using:

    foreach (string file in selectedFiles)
{
    miLista.Items.Add(file); 
    // No es necesaria la instancia de ListBoxItem ya que puedes agregar
    // objects de cualquier tipo.
}

    And then:

    string[] Matriz = miLista.Items.Cast<string>().ToArray();
// Asignas el valor directamente.

    With this you directly have an array stringwith all the values.

    EDIT: I clarify that Cast<string>()it should not be necessary since we are adding items of type stringto list.

    If the above doesn't work for you, you can try combining Alan's answer and this one:

    string[] Matriz = new string[miLista.Items.Count];
for (int i = 0; i < miLista.Items.Count; i++)
    Matriz[i] = miLista.Items[i].ToString();

    This is supposed to work, since you have elements of type string insideListBox.Items

    In case none works for you, you have an array of strings in which it OpenFileDialogis FileNamesalready a type, you string[]should only do this:

    string[] Matriz = ofd.FileNames; // donde ofd es tu OpenFileDialog.
foreach (string s in Matriz)
    miLista.Items.Add(s); // Agrega al listbox los elementos de la Matriz.

    Sometimes the order of the instructions can be wrong, but it can work either way.

    Here I leave you the response from SO where I found something similar, greetings!

    • 2