C# Text box remaining empty - c#

I'm calling a public method from another class. It takes in a List as a parameter, and goes through the list printing out each item into a text field. The problem is the text field is remaining empty!. I've checked that the list is populated by outputing the item to the console before I put it into the text box, and the text is coming up fine there.
The list contains strings, and should output each string to the textfield followed by a semi colon.
This is the method which is being called:
public void fillAttachment(List<string> attachList)
{
for (int i = 0; i < attachList.Count; i++)
{
Console.WriteLine("List: " + attachList[i]);
txtAttach.Text += attachList[i] + ";";
}
}

I would solve it in this way:
foreach(var attach in attachList)
{
Console.WriteLine(attach);
txtAttach.AppendText(string.Format("{0};", attach));
}

Setting the text property on a text box and it not displaying could be one of the following:
You are not looking at the same control as you are setting the text in
Could you have instantiated a second copy of the form object and it is this form that you are setting the txtAttach text property in?
Could the control that you are expecting to be populated be a different one? Right click the text box that you want the text to appear in click properties and check the name.
Something else is clearing the textbox after you set it
Right click the txtAttach.Text and click Find All References, this will show you all the places that the Text property is referenced - written and read - in your project. This is a very useful way to locate other interaction with this control.
Fomatting is making the text box appear empty
Is the Font too small, or in the same colour as the background. Can you select the text in the text box?
The easiest way to test all of the above is to create a new text control on your form with a different name, change your code to populate it, check that it is indeed populated, then replace the old one.
As an aside, you could also reduce the code with a single line as follows:
public void fillAttachment(List<string> attachList)
{
txtAttach.Text = String.Join(";", attachList.ToArray());
}
Although this obviously skips out the console write line function.

Not sure why yours doesn't work but I would have done it like this...
public void fillAttachment(List<string> attachList)
{
string result = "";
//OR (if you want to append to existing textbox data)
//string result = txtAttach.Text;
for (int i = 0; i < attachList.Count; i++)
{
Console.WriteLine("List: " + attachList[i]);
result += attachList[i] + ";";
}
txtAttach.Text = result;
}
Does that work for you? If not then there is something else very wrong that is not obvious from your code

Related

Reading a .txt file line by line into multiple text boxes with buttons in a c# windows form

I have got a txt file with 10 lines in it, each line is a record with 5 different fields;
Farrell,Jade,Louise,2011/09/13,F
I am using the commas to split record by FamilyName, FirstName, MiddleName, EnrolmentDate and Gender. I want each field to have its own text box then use buttons to look through the different records.
Everything so far is working under the load button which reads the data from the file and puts it into the text boxes using the code below which works but it only shows the first record so i want a buttons to show the next record, previous record, first and last record and also a button to sort the data from A-Z by the family name. Any help on how to go forward would be great! thanks!
private void Load_BT_Click(object sender, EventArgs e)
{
OpenFileDialog filechooser = new OpenFileDialog();
StreamReader filereader = new StreamReader("StudentFile.txt");
String inputrecord = filereader.ReadLine();
string[] inputfields;
if (inputrecord != null)
{
inputfields = inputrecord.Split(',');
FamName_TXT.Text = inputfields[0];
FirstName_TXT.Text = inputfields[1];
MiddleName_TXT.Text = inputfields[2];
Enrolment_txt.Text = inputfields[3];
Gender_TXT.Text = inputfields[4];
}
else
{
MessageBox.Show("End of File");
}
}
I think there are some design issues here, but i will address your immediate concern. The problem is you only read one line. You need to iterate over all the lines in the textfile. I am assuming you want the load button to load all the data at once.
string[] allRecords = filereader.ReadAllLines();
foreach(string inputRecord in allRecords) {
string[] inputfields = inputRecord.Split(',');
//insert the textbox.Text += inputfields[0] + "\n"; etc
}
if you want a single button to resort the data across all the textboxes.
you really should create a class called Person with properties that correspond to your fields and override compareTo so you can sort by last name or maybe use linq to do the sort for you.
you need a list that will host all of these person objects
from there you can populate the textboxes accordingly
Create a sort button that will reorder the list or create a new list and repopulate the textboxes.
1-3 would be done in the load button. The reason for the person class is because you want all the data you read in from the file to be associate with an object. if you try to do the sorting directly from the textboxes as you seem to be trying to do you will run into issues such as how to make sure the data doesnt get jumbled. It certainly may be possible but it is not an elegant way and would be more work in my mind

InOrder sorting of a class within a AVLTtree by name to a text box

I appear to have the tree displayed in order, however i want to display the country name in the text box instead of what it is currently giving me Here is the code I have currently have relating to this issue. An FYI the tree populates from a file read in.
I want in the text box Argentina, Australia, Brazil, etc. but current have "FormWork.Country, FormWork.Country, etc". Looking at them in the Autos shows they are the correct order, just not returning the Name only.
This is within Form1.cs
public partial class Form1 : Form
{
AVLTree<Country> countryTree = new AVLTree<Country>();
string buffer = null;
public form1()
{
LoadFile();
InitializeComponent();
orderTree();
}
public void orderTree()
{
countryTree.InOrder(ref buffer);
txtOrder.Text = buffer;
}
}
This is where .InOrder is
My issues seems to be that I can't specifically retrieve "tree.Data.countryName" from the Country.cs class
instead of calling
buffer += tree.Data.toString() + ",";
in the buffer append line of your in-order traversal, call something along the lines of
buffer += tree.Data.CountryName + ", ";
to access the string of the property you are trying to print rather than a representation of the Country object which will be "FormWork.Country".
Second off, you should put all of your code in the question rather than linking to 2 different places.

Using a listbox in C#

I'm trying to load a form with different information depending on which component of my listbox I double click. If I get which box was clicked(box 1, box2, etc.), that would be enough.
I've tried using the Doubleclick event, but it returns an object, and I'm not quite sure what to do with this object to get what I need.
Heres my code right now:
for (int i = 0; i <= (Program.Customers.Count) - 1; i++)
{
if (Program.Customers[i].Name == searchTerm)
{
SearchIndex.Add(i);
listBox1.Items.Add(((Program.Customers[i].ID + " - " + Program.Customers[i].Name)));
}
}
listBox1.Show();
What would be the best way to get which box was clicked? I need the ID, but I can get that with box was clicked.
Thanks!
In the simplest case, you can directly compare the sender argument with your ListBox control instances, for example:
if (sender == listBox1)
{
// ...
}
To get more information out of sender you need to cast it to something more specific first. So if you know your double click handler was only attached to list boxes, you can do
var listbox = (ListBox)sender;
and then access any of the properties of ListBox (such as Tag, which I mention because it's there specifically for your custom needs).

Combobox crashes when selecting item with keyboard

I have a problem with the code below, basically what is does is read from a path where files with extension .config are stored, it reads the names of the files without extension and displays them all in a combobox. That works fine and if you click on the down arrow and select a name it actually does what it's supposed to, however, once I have selected an item from the dropdown with the mouse and I go back and start typing inside the combobox my application crashes throwing a exception.
I've tried adding a try-catch-finally but it keeps throwing the same error. Could it be the loop that is causing my application to crash once I start typing in the combobox?
p.d. If I just use the mouse to select an item from the dropdown menu my application works fine but once I've selected an item with the mouse and use the keyboard to type another item name inside the combobox my app crashes. Any pointers would be helpful.
// Gets all the file names from the path assigned to templatePath
// and assigns it to the string array fname
string[] fname = Directory.GetFiles(templatePath);
// Begin sorting through the file names assigned to the string array fname
foreach (string file in fname)
{
// Remove the extension from the file names and compare the list with
// the dropdown selected item
if (System.IO.Path.GetFileNameWithoutExtension(file) == cbTemplates.SelectedItem.ToString())
{
// StreamReader gets the contents from the found file and assigns
// them to the labels
using (var obj = new StreamReader(File.OpenRead(file)))
{
lbl1.Content = obj.ReadLine();
lbl2.Content = obj.ReadLine();
lbl3.Content = obj.ReadLine();
lbl4.Content = obj.ReadLine();
lbl5.Content = obj.ReadLine();
lbl6.Content = obj.ReadLine();
lbl7.Content = obj.ReadLine();
lbl8.Content = obj.ReadLine();
lbl9.Content = obj.ReadLine();
lbl10.Content = obj.ReadLine();
obj.Dispose();
}
}
}
My guess is this is probably causing the error:
cbTemplates.SelectedItem.ToString()
When you start typing in the combobox, the SelectedItem becomes null.
You should test whether the cbTemplates.SelectedItem is null before attempting to invoke ToString() on it. And if you're trying to match on the text of the combo-box, you might try using cbTemplates.Text instead.
And as others commented on your question, you don't need to call Dispose inside using and you should consider the possibility that the file might not contain 10 lines..

Assistance regarding tabs in Windows Forms

I'm currently working on a small side project as a way of getting used to Forms in Visual Studio 2012, as I usually only work with Console Applications. My current layout is designed to use tabs, and the user is to specify how many of the tabs they need for this application. They then fill out some information and it will be formatted and output to a file at a location specified by the user. On to the questions.
In order to stop duplicate tabs from existing, I'm using the following:
private void comboTabs_SelectedIndexChanged(object sender, EventArgs e)
{
if (comboSkills.SelectedIndex == 0)
{
tabControl1.TabPages.Remove(tab8);
tabControl1.TabPages.Remove(tab7);
tabControl1.TabPages.Remove(tab6);
tabControl1.TabPages.Remove(tab5);
tabControl1.TabPages.Remove(tab4);
}
//repeat for Index 1, 2 and so on
}
There will always be a minimum of 3 tabs, so the first selection on the combo box removes tabs 4 through 8. The next selection does the same, but then adds tab4 back again. This goes on for the following selections. Is there any way I can do this more conveniently?
Second question, each tab has a series of text boxes and combo boxes that users are to select information from. The problem I'm having is that I need to identify how many tabs the user has selected and then only pull information from those tabs. I'm aware that I can get the number of tabs with:
int numberoftabs = tabControl1.TabCount;
But after that I can't seem to read the information from them. I'm intending to do
for (int i = 0; i < numberoftabs; i++)
{
//get textbox text of tab i and so on
}
Is there any way I can do this? I was hoping to use a tab layout since I like my current layout very much. If it makes a difference, all the tabs have the same layout, and share a naming convention such as tab 1 text box 1 is textTab1Name, tab 2 text box 2 is textTab2Name and so on.
For the first part of your question, you can handle all cases with this piece of code:
var tabCount = 5 - comboBox1.SelectedIndex;
for (var i = 0; i < tabCount; i++)
{
tabControl1.TabPages.RemoveAt(7-i);
}
For the second part you will have to create this method:
private T GetControl<T>(string name) where T : Control
{
return (T) this.Controls.Find(name, true).FirstOrDefault();
}
Then you can write your text retrieval loop like this:
for (int i = 0; i < numberoftabs; i++)
{
//get textbox text of tab i and so on
TextBox textBox1 = GetControl<TextBox>("textTab" + i + "Name");
...
etc..
}

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