CODEWITHSUNDEEP
c#wpfopenfiledialog
PiotrG
PiotrG

Reputation: 871

How would I reference a variable obtained from a private function in another function?

I'm hoping someone can help me. I am relatively new and would like to understand how to pass the value of the variable in one class to another. In this case I would like to use numPage and filePath array from Button_Click_1 in Button_Click_2.

Thank you in advance!

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void Button_Click_1(object sender, RoutedEventArgs e)
    {
        Microsoft.Win32.OpenFileDialog openFileDialog1 = new Microsoft.Win32.OpenFileDialog();

        openFileDialog1.Filter = "Images (.jpg)|*.jpg";
        openFileDialog1.FilterIndex = 1;

        openFileDialog1.Multiselect = true;

        bool? userClickedOK = openFileDialog1.ShowDialog();

        if (userClickedOK == true)
        {
            string[] filePaths = openFileDialog1.FileNames;
            int imageNum = 0;
            lblFilePath.Content = filePaths[imageNum];
        }

    }

    private void Button_Click_2(object sender, RoutedEventArgs e)
    {
        imageNum++;
        lblFilePath.Content = filePath[imageNum];
    }
}

Upvotes: 1

Views: 1472

Answers (4)

Timothy Schoonover
Timothy Schoonover

Reputation: 3265

You would just need to store them as class instance variables instead of local method variables.

public partial class MainWindow : Window
{
    // These can now be accessed from any method in this class.
    private string[] filepaths = null;
    private int imageNum = 0;

    public MainWindow()
    {
        InitializeComponent();
    }

    private void Button_Click_1(object sender, RoutedEventArgs e)
    {
        Microsoft.Win32.OpenFileDialog openFileDialog1 = new Microsoft.Win32.OpenFileDialog();

        openFileDialog1.Filter = "Images (.jpg)|*.jpg";
        openFileDialog1.FilterIndex = 1;

        openFileDialog1.Multiselect = true;

        bool? userClickedOK = openFileDialog1.ShowDialog();

        if (userClickedOK == true)
        {
            // You can use the keyword "this" to access instance variables, but it is optional.
            this.filePaths = openFileDialog1.FileNames;
            this.imageNum = 0;
            lblFilePath.Content = this.filePaths[this.imageNum];
        }

    }

    private void Button_Click_2(object sender, RoutedEventArgs e)
    {
        // You may want to put some validation in here to prevent errors situations.

        // Validate that filePaths has been initialized.
        if (this.filePaths == null)
        {
           System.Windows.Forms.MessageBox.Show("No files paths to display.");
        }
        // Validate that imageNum can be incremented without IndexOutOfRangeException.
        else if (this.imageNum < this.filePaths.Length - 1)
        {
            this.imageNum++;
            lblFilePath.Content = this.filePaths[this.imageNum];
        }
        // Otherwise, loop back to the first file path.
        else
        {
            this.imageNum = 0;
            lblFilePath.Content = this.filePaths[this.imageNum];
        }
    }
}

Upvotes: 3

TalentTuner
TalentTuner

Reputation: 17556

make both as properties of form 1 

public partial class MainWindow : Window
{

   private string[] FilePaths {get;set;}
   int imageNum = 0;

   public MainWindow()
   {
    InitializeComponent();
   }

private void Button_Click_1(object sender, RoutedEventArgs e)
{
    Microsoft.Win32.OpenFileDialog openFileDialog1 = new Microsoft.Win32.OpenFileDialog();

    openFileDialog1.Filter = "Images (.jpg)|*.jpg";
    openFileDialog1.FilterIndex = 1;

    openFileDialog1.Multiselect = true;

    bool? userClickedOK = openFileDialog1.ShowDialog();

    if (userClickedOK == true)
    {
        FilePaths = openFileDialog1.FileNames;

        lblFilePath.Content = filePaths[imageNum];
    }

}

private void Button_Click_2(object sender, RoutedEventArgs e)
{
    imageNum++;
     if(imageNum<FilePaths.Length)
         lblFilePath.Content = FilePaths[imageNum];
}

}

Upvotes: 0

Servy
Servy

Reputation: 203837

You need to create instance variables here, rather than scoping the variables to be local to the method:

public partial class MainWindow : Window
{
    private string[] filePaths;
    private int imageNum = 0;

    //...

}

Then you can use those instance variables (make sure to not re-define new local variables with the same name) in the two methods.

Upvotes: 0

Ralf de Kleine
Ralf de Kleine

Reputation: 11744

Use a property in class MainWindow.

private string[] FilePaths{get;set;}

Replace variable filePath with FilePath.

Upvotes: 4

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