obtenir la valeur de la zone de texte dynamique

Question

J'ai quelques tableaux pour enregistrer mes contrôles. quand appeler une fonction initialise des tableaux et enregistre dans mes tableaux mes contrôles.

code:

private Label[] lblName; 
    private TextBox[] txtName; 
    private Label[] lblSurname; 
    private TextBox[] txtSurname; 
    private Label[] lblInstitution; 
    private TextBox[] txtInstitution; 
    private Label[] lblCountry; 
    private TextBox[] txtCountry; 
    private Label[] lblEmail; 
    private TextBox[] txtEmail; 
    private PlaceHolder PlaceHolder1; 


    public int NumberOfOtherAuthors() 
    { 
     Int32 index = Convert.ToInt32(NumberList.SelectedValue); 
     return index; 
    } 

    public void GUIofOtherAuthor() 
    { 
     int authors; 
     int i = 0; 
     int j = 1; 


     authors = NumberOfOtherAuthors(); 
     lblName = new Label[authors]; 
     txtName = new TextBox[authors]; 
     lblSurname = new Label[authors]; 
     txtSurname = new TextBox[authors]; 
     lblInstitution = new Label[authors]; 
     txtInstitution = new TextBox[authors]; 
     lblCountry = new Label[authors]; 
     txtCountry = new TextBox[authors]; 
     lblEmail = new Label[authors]; 
     txtEmail = new TextBox[authors]; 
     PlaceHolder1 = new PlaceHolder(); 


     for (i = 0; i < authors; i++) 
     { 
      Label authorInformation = new Label(); 
      authorInformation.Text = "Information for Author " + j.ToString() + " :"; 

      lblName[i] = new Label(); 
      lblName[i].Text = "Name:"; 
      txtName[i] = new TextBox(); 
      lblSurname[i] = new Label(); 
      lblSurname[i].Text = "Surname:"; 
      txtSurname[i] = new TextBox(); 
      lblInstitution[i] = new Label(); 
      lblInstitution[i].Text = "Institution:"; 
      txtInstitution[i] = new TextBox(); 
      lblCountry[i] = new Label(); 
      lblCountry[i].Text = "Country:"; 
      txtCountry[i] = new TextBox(); 
      lblEmail[i] = new Label(); 
      lblEmail[i].Text = "Email:"; 
      txtEmail[i] = new TextBox(); 

      PlaceHolder1.Controls.Add(new LiteralControl("<table>")); 
      PlaceHolder1.Controls.Add(new LiteralControl("<span style=\"font-weight:bold;\" ")); 
      PlaceHolder1.Controls.Add(authorInformation); 
      PlaceHolder1.Controls.Add(new LiteralControl("</span>")); 
      PlaceHolder1.Controls.Add(new LiteralControl("<tr><td>")); 
      PlaceHolder1.Controls.Add(lblName[i]); 
      PlaceHolder1.Controls.Add(new LiteralControl("</td><td>")); 
      PlaceHolder1.Controls.Add(txtName[i]); 
      PlaceHolder1.Controls.Add(new LiteralControl("</td></tr>")); 
      PlaceHolder1.Controls.Add(new LiteralControl("<tr><td>")); 
      PlaceHolder1.Controls.Add(lblSurname[i]); 
      PlaceHolder1.Controls.Add(new LiteralControl("</td><td>")); 
      PlaceHolder1.Controls.Add(txtSurname[i]); 
      PlaceHolder1.Controls.Add(new LiteralControl("</td></tr>")); 
      PlaceHolder1.Controls.Add(new LiteralControl("<tr><td>")); 
      PlaceHolder1.Controls.Add(lblInstitution[i]); 
      PlaceHolder1.Controls.Add(new LiteralControl("</td><td>")); 
      PlaceHolder1.Controls.Add(txtInstitution[i]); 
      PlaceHolder1.Controls.Add(new LiteralControl("</td></tr>")); 
      PlaceHolder1.Controls.Add(new LiteralControl("<tr><td>")); 
      PlaceHolder1.Controls.Add(lblCountry[i]); 
      PlaceHolder1.Controls.Add(new LiteralControl("</td><td>")); 
      PlaceHolder1.Controls.Add(txtCountry[i]); 
      PlaceHolder1.Controls.Add(new LiteralControl("</td></tr>")); 
      PlaceHolder1.Controls.Add(new LiteralControl("<tr><td>")); 
      PlaceHolder1.Controls.Add(lblEmail[i]); 
      PlaceHolder1.Controls.Add(new LiteralControl("</td><td>")); 
      PlaceHolder1.Controls.Add(txtEmail[i]); 
      PlaceHolder1.Controls.Add(new LiteralControl("</td></tr>")); 
      PlaceHolder1.Controls.Add(new LiteralControl("</table><br /> ")); 
      Panel1.Controls.Add(PlaceHolder1); 

      j++; 
     } 
    } 

Maintenant, je veux prendre la valeur de la fonction textboxes dans une autre public void UploadForm(){...}. je l'essaye

int i; 
int numberOfOtherAuthors = NumberOfOtherAuthors(); 

for(i=0; i<numberOfOtherAuthors; i++) 
{ 
    String a = txtname[i].text 
} 

Les valeurs TextBoxes que je veux télécharger la base de données, mais disons que nous les sauvions à une chaîne. Lorsque je fais cela, j'ai l'exception NullReferenceException. Alors, comment obtenir la valeur de ce texte ??? Merci

Answer 1

j'ai remarqué que votre fonction UploadForm() fait référence txtname, alors que votre TextBox réelle est déclarée comme txtName. Comme les noms de champs sont sensibles à la casse, le champ "txtname" (minuscule "n") n'est pas réellement défini, c'est donc probablement la cause de votre NullReferenceException dans votre page dynamique.