在 C# 中获取组合框文本

Question

I filled up a combobox with the values from an Enum.

Now a combobox is text right? So I'm using a getter and a setter. I'm having problems reading the text.

Here's the code:

public BookType type
{
    get
    {
        return (BookType)Enum.Parse(typeof(BookType), this.typeComboBox.Text);
    }
    set
    {
        this.typeComboBox.Text = value.ToString();
    }
}

For some reason, this.typeComboBox.Text always returns an empty string when I select an item on the combobox.

Does someone see what I'm doing wrong?

EDIT: I have come to the conclusion that the problem lies in timing. The point in time at which I summon the text is indeed after I changed the combobox, but still before that value is parsed as a value. Problem fixed in a different way now, thanks for all the ideas.

Answer 1

Try this. this worked for me.

string selectedText = this.ComboBox.GetItemText(this.ComboBox.SelectedItem);

The GetItemText method analyzes the item and returns the text of the bound to that item.

Answer 2

Set the DropDownStyle of the ComboBox to DropDownList . This will ensure that only the elements already in the list can be selected (no need to check that the text actually is a valid value). Then if you use Enum.GetValues(typeof(BookType)) to fill the combobox then typeComboBox.SelectedItem property will be a value of BookType . So you can use this in the property getter and setter.

So to summarize. You don't have to bind the combobox to a list of text values as long as you use the DropDownList style. Use the SelectedItem property to get an item of the wanted type instead of checking the Text property.

Edit: You may have to check the SelectedItem property for null

Answer 3

The combobox starts at index -1, which has no text, thus an empty string: ""

I then change the index to a BookType that I need and then I get the wrong output...

Answer 4

你应该试试 this.typeComboBox.SelectedItem.ToString()

Answer 5

您是否尝试过使用this.typeComboBox.SelectedText而不是typeComboBox.Text ？

Answer 6

I just created a simple windows form, and everything worked okay for me. Here is the code.

public enum Test
{
    One, Two, Three
}

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        this.comboBox1.DataSource = Enum.GetNames(typeof(Test));
    }

    public Test Test
    {
        get 
        {
            return (Test)Enum.Parse(typeof(Test), this.comboBox1.Text);
        }
        set
        {
            this.comboBox1.Text = value.ToString();
        }
    }

    private void button1_Click(object sender, EventArgs e)
    {
        MessageBox.Show(this.Test.ToString());

        this.Test = Test.Two;

        MessageBox.Show(this.Test.ToString());
    }
}

Answer 7

private void ComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    var comboBox = (ComboBox)sender;
    ComboBoxItem comboAsTextblock = (ComboBoxItem)comboBox.SelectedItem;
    string comboBoxItemText = comboAsTextblock.Content.ToString();
    // comboBoxItemText is what you want :)
}