Can we extract the status of checkboxes in pdf file using c#?

Free Spire.PDF library supports creating and reading pdf form fields.

You can install Free Spire.PDF via Nuget Package Manager, and then use the following code to read values of form fields such as textbox, listbox, combo box, radio button and checkbox in PDF.

StringBuilder sb = new StringBuilder();
//Load a pdf document
string input = @"..\..\..\..\..\..\Data\AllFields.pdf";
PdfDocument doc = new PdfDocument();
doc.LoadFromFile(input);
//Get pdf forms
PdfFormWidget formWidget = doc.Form as PdfFormWidget;
//Find pdf form fields
for (int i = 0; i < formWidget.FieldsWidget.List.Count; i++)
{
PdfField field = formWidget.FieldsWidget.List[i] as PdfField;
if (field is PdfTextBoxFieldWidget)
{
PdfTextBoxFieldWidget textBoxField = field as PdfTextBoxFieldWidget;
//Get text of textbox
string text = textBoxField.Text;
sb.Append("The text in textbox is " + text + "\r\n");
}
if (field is PdfListBoxWidgetFieldWidget)
{
PdfListBoxWidgetFieldWidget listBoxField = field as PdfListBoxWidgetFieldWidget;
sb.Append("Listbox items are \r\n");
//Get values of listbox
PdfListWidgetItemCollection items = listBoxField.Values;
foreach (PdfListWidgetItem item in items)
{
sb.Append(item.Value + "\r\n");
}
//Get selected value
string selectedValue = listBoxField.SelectedValue;
sb.Append("The selected value in the listbox is " + selectedValue + "\r\n");
}
if (field is PdfComboBoxWidgetFieldWidget)
{
PdfComboBoxWidgetFieldWidget comBoxField = field as PdfComboBoxWidgetFieldWidget;
sb.Append("comBoxField items are \r\n");
//Get values of comboBox
PdfListWidgetItemCollection items = comBoxField.Values;
foreach (PdfListWidgetItem item in items)
{
sb.Append(item.Value + "\r\n");
}
//Get selected value
string selectedValue = comBoxField.SelectedValue;
sb.Append("The selected value in the comBoxField is " + selectedValue + "\r\n");
}
if (field is PdfRadioButtonListFieldWidget)
{
PdfRadioButtonListFieldWidget radioBtnField = field as PdfRadioButtonListFieldWidget;
//Get value of radio button
string value = radioBtnField.Value;
sb.Append("The text in radioButtonField is " + value + "\r\n");
}
if (field is PdfCheckBoxWidgetFieldWidget)
{
PdfCheckBoxWidgetFieldWidget checkBoxField = field as PdfCheckBoxWidgetFieldWidget;
//Get the checked state of the checkbox
bool state = checkBoxField.Checked;
sb.Append("If the checkBox is checked: " + state + "\r\n");
}
}
string result = "GetAllValues.txt";
File.WriteAllText(result, sb.ToString());

5 Replies

Know the answer? Post it — somebody with the same question will find it here.

Leon D5y ago
Accepted answer
I am afraid it's hard to read values of such textboxes. However, Free Spire.PDF supports reading text from Pdf page or from a particular rectangular area of a page, you may give it a try. Refer the following documentations.

https://www.e-iceblue.com/Tutorials/Spire.PDF/Spire.PDF-Program-Guide/Read-PDF-Read-PDF-Images-and-Text-in-C-VB.NET.html

https://www.e-iceblue.com/Tutorials/Spire.PDF/Spire.PDF-Program-Guide/Extract/Read/Extract-Text-from-a-Specific-Rectangular-Area-in-PDF-using-C.html
vishnu pc5y ago
Thank you Leon D for the support

I tried this code and it is really helpfull, but I have a problem, the pdf that I want to extract checkbox values dont have specific forms in it. Checkboxes placed here and there . Is there any way to read values of those kind of checkboxes..?
Leon D5y ago
Free Spire.PDF library supports creating and reading pdf form fields.

You can install Free Spire.PDF via Nuget Package Manager, and then use the following code to read values of form fields such as textbox, listbox, combo box, radio button and checkbox in PDF.
StringBuilder sb = new StringBuilder();

           //Load a pdf document
           string input = @"..\..\..\..\..\..\Data\AllFields.pdf";
           PdfDocument doc = new PdfDocument();
           doc.LoadFromFile(input);

           //Get pdf forms
           PdfFormWidget formWidget = doc.Form as PdfFormWidget;

           //Find pdf form fields
           for (int i = 0; i < formWidget.FieldsWidget.List.Count; i++)
           {
               PdfField field = formWidget.FieldsWidget.List[i] as PdfField;
               if (field is PdfTextBoxFieldWidget)
               {
                   PdfTextBoxFieldWidget textBoxField = field as PdfTextBoxFieldWidget;
                   //Get text of textbox
                   string text = textBoxField.Text;
                   sb.Append("The text in textbox is " + text + "\r\n");
               }

               if (field is PdfListBoxWidgetFieldWidget)
               {
                   PdfListBoxWidgetFieldWidget listBoxField = field as PdfListBoxWidgetFieldWidget;
                   sb.Append("Listbox items are \r\n");
                   //Get values of listbox
                   PdfListWidgetItemCollection items = listBoxField.Values;

                   foreach (PdfListWidgetItem item in items)
                   {
                       sb.Append(item.Value + "\r\n");
                   }
                   //Get selected value
                   string selectedValue = listBoxField.SelectedValue;
                   sb.Append("The selected value in the listbox is " + selectedValue + "\r\n");

               }

               if (field is PdfComboBoxWidgetFieldWidget)
               {
                   PdfComboBoxWidgetFieldWidget comBoxField = field as PdfComboBoxWidgetFieldWidget;
                   sb.Append("comBoxField items are \r\n");
                   //Get values of comboBox
                   PdfListWidgetItemCollection items = comBoxField.Values;

                   foreach (PdfListWidgetItem item in items)
                   {
                       sb.Append(item.Value + "\r\n");
                   }
                   //Get selected value
                   string selectedValue = comBoxField.SelectedValue;
                   sb.Append("The selected value in the comBoxField is " + selectedValue + "\r\n");

               }

               if (field is PdfRadioButtonListFieldWidget)
               {
                   PdfRadioButtonListFieldWidget radioBtnField = field as PdfRadioButtonListFieldWidget;
                   //Get value of radio button
                   string value = radioBtnField.Value;

                   sb.Append("The text in radioButtonField is " + value + "\r\n");
               }

               if (field is PdfCheckBoxWidgetFieldWidget)
               {
                   PdfCheckBoxWidgetFieldWidget checkBoxField = field as PdfCheckBoxWidgetFieldWidget;
                   //Get the checked state of the checkbox
                   bool state = checkBoxField.Checked;
                   sb.Append("If the checkBox is checked: " + state + "\r\n");
               }
           }
           string result = "GetAllValues.txt";

           File.WriteAllText(result, sb.ToString());
vishnu pc5y ago
Thanks salman for the reply , I have tried this before but it is not working .
Salman Beg5y ago
See this link may help you, https://stackoverflow.com/questions/25210668/how-to-check-if-a-checkbox-is-checked-or-not-on-a-non-form-pdf-using-c