I have a WPF application, that has a number TextBox elements. The user fills those out, and the application then prints them. The problem with TextBoxes is that if you keep typing in one, once you fill it out to the end, the text starts scrolling horizontally to make room for more letters, and you no longer see the first couple letters that were typed in.
It was decided that the solution is to prevent the user from entering more text that will fit inside the TextBox. What's the best way of going about it?
I looked at TextBox properties, and didn't see anything that would do what I want directly. The first idea, is to set wrapping to Wrap. Then subscribe to PreviewTextInput event, and if the number of lines is going to exceed 1, handle the event without adding newly typed in text. Obviously you'll still be able to get around it by pasting text, but the bigger issue is that it will only work for single line TextBoxes, and I need it to work with multiline TextBoxes as well.
Is there a better approach that I'm missing? Would calculating text width, and then making sure it's less than TextBox width/height (how?) be a better option? Or perhaps another solution?
Here's my final solution, that also works for multiline TextBoxes. It will even work when pasting-in text. The only weirdness is that I delete trailing characters when text overflows, and that may seem strange if you are typing in text in the middle of the text box. I tried working around that by removing characters at the point of CaretIndex, but it was getting too involved. But other than that it does what I need it to do. To improve performance you can cache results from GetLineHeight function, so that you only need to call it once per TextBox (EDIT - I added the code for that as well).
<TextBox Height="23" Width="120" TextWrapping="Wrap" TextChanged="TextBoxTextChanged" AcceptsReturn="True"/>
private void TextBoxTextChanged(object sender, TextChangedEventArgs e)
{
TextBox textBox = sender as TextBox;
if (textBox == null)
return;
double textLineHeight = GetCachedTextLineHeight(textBox);
int maxTextBoxLines = (int)(textBox.ViewportHeight / textLineHeight);
while (textBox.LineCount > maxTextBoxLines) //if typed in text goes out of bounds
{
if (textBox.Text.Length > 0)
textBox.Text = textBox.Text.Remove(textBox.Text.Length - 1, 1); //remove last character
if (textBox.Text.Length > 0)
textBox.CaretIndex = textBox.Text.Length;
}
}
private double GetTextLineHeight(TextBox textBox)
{
FormattedText formattedText = new FormattedText(
"a",
CultureInfo.CurrentUICulture,
FlowDirection.LeftToRight,
new Typeface(textBox.FontFamily, textBox.FontStyle, textBox.FontWeight, textBox.FontStretch),
textBox.FontSize,
Brushes.Black);
return formattedText.Height;
}
#region Caching
Dictionary<TextBox, double> _cachedLineHeights = new Dictionary<TextBox, double>();
private double GetCachedTextLineHeight(TextBox textBox)
{
if (!_cachedLineHeights.ContainsKey(textBox))
{
double lineHeight = GetTextLineHeight(textBox);
_cachedLineHeights.Add(textBox, lineHeight);
}
return _cachedLineHeights[textBox];
}
#endregion
You're looking for the MaxLength property. You'll have to experiment with the number since you need to remember that you can fit a lot of i's in the space you can fit one W in. Typically when I size TextBoxes, I size and set the max length based on W's since thats the widest character.
EDIT: just saw you want it to work with multi-line text boxes too... in that case, just set it to wrap and it won't scroll horizontally.
Related
I am working with c#.
My goal is to be able to add an integer to a free response textbox. Allow me to explain.
I have a textbox called (Red,Green,Blue). Each color will be replaced using the Replace(); method.
Like this:
private void RedTextBox_TextChanged(object sender, EventArgs e) //ActualFogColor is Result
{
string ActualColorFog = "game.Lighting.FogColor = Color3.new(Red,Green,Blue)";
string Red = RedTextBox.Text;
string FogColorRed = ActualColorFog.Replace("Red", Red);
ActualColorFogScript.Text = FogColorRed;
}
This repeats for all other colors and it works fine. The problem I have is that I have a brightness button that when you click it, it adds 1 to the inputted number, but of course I had to convert it into an integer. It is basically initial + 1 = the new color. Replace Initial with new color and print that on the textbox.
Unfortunately i can't do
public partial class main : Form
{
int red = Convert.ToInt32(RedTextbox.Text); }
This is at the very top of the code which is why when doing this, it doesn't recognize RedTextBox.
The reason I am trying to assign the integer to the textbox is so that when the " RedTextBox.Text = '5' " It will take that 5 and add 1(by a button) which then prints the sum which I set equal to Red in string ActualColorFog = "game.Lighting.FogColor = Color3.new(Red,Green,Blue)";
I hope this make sense to you all, if you are confused on my plan, please leave your question.
I'd suggest you take one step back and think about the usability of your inputs. What I mean if you allow the user to freely enter the text, you have to tackle the input values like negative numbers, literals, numbers outside of the range (0-255 I presume), non-integer input, etc. Furthermore it would be nice if the user can use mouse scroll to increase/decrease the value. Perhaps a numeric up-down would be solution for your problem? It's not a standard control but there are enough implementations of it freely available.
Should you insist on using the text input, do the following:
define 3 integer member variables in your code for the components.
provide the Changed event handler for each textbox where you int.TyParse the input, check the ranges and if all goes well and update the respective member variable if it differs from the new value
probably add mouse scroll event handler
your button's Click event handler will update the member variables and the text values in the textboxes
A nicer solution would be to use the dependency properties instead of member variables, the content of the textboxes is bound to the dependency variables one way and the textboxes' Checked event handler does the parsing.
I am not getting into that if your method is good or not but just how to solve this problem.
As i can see, ideal for you would be that you can assign int red = Convert.ToInt32(RedTextbox.Text); and you cannot because it is at top of your code?
It is not recognizing because that part of code is accessed before RedTextBox is even initialized. Solution for this is to put int red = -1; and then
public main() //Your form constructor
{
InitializeComponents();
// I guess you somehow add some value to RedTextbox on form
showing so it need to be before assigning red variable
red = Convert.ToInt32(RedTextbox.Text); //It is important to be after Initializecomponents()
}
I am trying to create a form with a multi-line TextBox with the following requirements:
The text in the text box might be short or long.
There is not much space availble.
I want to be sure that the entirety of the text has been seen. I can't be sure that the user has actually read it, but I can at least require that all of it has been seen.
So I'm trying to make a "fully viewed" multi-line TextBox.
This picture should make it clear what I'm trying to do:
If they check the checkbox before they've scrolled through the whole thing, I'll know not to believe them.
I think I need to know:
When the form comes up, was the text that was put into the TextBox short (all visible without scrolling) or long (the vertical scroll bar was shown)?
If the vertical scroll bar is showing, has the user scrolled it all the way to the bottom?
Any ideas about how to achieve this?
The TextBox has no scrolling event but the RichTextBox has. Also it has a method that allows you to get the index of the character closest to a point position.
private readonly Point _lowerRightCorner;
public frmDetectTextBoxScroll()
{
InitializeComponent();
_lowerRightCorner = new Point(richTextBox1.ClientRectangle.Right,
richTextBox1.ClientRectangle.Bottom);
}
private void richTextBox1_VScroll(object sender, EventArgs e)
{
int index = richTextBox1.GetCharIndexFromPosition(_lowerRightCorner);
if (index == richTextBox1.TextLength - 1) {
// Enable your checkbox here
}
}
I made a Form with a TextBox that accepts a word and searches a bunch of sentences to see if any of them contains that word .After that I have to appear those sentences and highlight the word .My plan is to make a ListBox and add the sentences inside of it. My problem is how to highlight the word (by changing the color I suppose) so it can be distinguished.
Is there a preferable way?
I chose ListBox so I can select the sentence I'm looking for.
Edit
According to #Thorsten Dittmar directions a create an owner drawn list box.
public partial class Form1 : Form
{
private List<string> _items;
public Form1()
{
InitializeComponent();
_items = new List<string>();
_items.Add("One");
_items.Add("Two");
_items.Add("Three");
listBox1.DataSource = _items;
}
private void listBox1_DrawItem(object sender, DrawItemEventArgs e)
{
e.DrawBackground();
e.DrawFocusRectangle();
e.Graphics.DrawString(_items[e.Index],
new Font(FontFamily.GenericSansSerif,
8, FontStyle.Bold),
new SolidBrush(Color.Red), e.Bounds);
}
}
How I'm going to split the sentence in order to draw only one word?
Edit2
The way I finally did it was to make two seperate components, to compine my options.
One was a ListBox with all the sentences colored and the option to select one
of those and the other one a RichBox with separate colored words since is to difficult
to achieve that with the ListBox (for me a least).
The way I accomplished that was by using a boolean array pointing which word should
be colored in each sentence.
for (int i = 0; i < words.Length; i++)
{
if (segments[i]) //<-boolean array
{
rich.SelectionColor = Color.Red;
rich.AppendText(words[i] + " ");
rich.SelectionColor = Color.Black;
}
else
{
rich.AppendText(words[i] + " ");
}
}
There is no standard way of doing it in Windows Forms. You'd have to render the list items manually (create an owner drawn list box). In WPF this would be an easy task.
EDIT
Drawing only part of a string in a different font is not an easy task. What I'd try is the following:
Introduce tokens that tell you "bold start" and "bold end" - a bit like in HTML. Let's call them the same as in HTML. So your string could look like this:
Hello, I am <b>bold</b> text<b>!</b>
Now I'd tokenize my string into text that is non-bold and text that is bold. I'd get the following parts:
Hello, I am
bold
text
!
Now I'd draw each part using the following algorithm:
Draw string in current format at current position x
increase position x by width of the string drawn in step 1
change formatting according to upcoming string
goto 1
In step 2 the Graphics.MeasureString method would be called to get the width of the string.
Doing this for the 4 sample parts above would result in:
Hello, I am
Hello, I am bold
Hello, I am bold text
Hello, I am bold text !
A simple TextBox can have its Foreground property set, but it applies to the entire text within the TextBox.
If you want specific words to be "highlighted", you either need to split the sentence in several TextBoxes (dirty), or make use of a RichTextBox
Giannosfor, in response to your comment, you'll have to use the parameter e of the event handler to choose which item you want to hightlight (link here).
Look at the response from Shadow Wizard and particularly at the use of e.Index.
Graphics g = e.Graphics;
...
g.FillRectangle(new SolidBrush(color), e.Bounds);
Variable g represent the graphic part of your current item e. Method FillRectangle allows you to change the color of the item's background.
Edit 1:
I tried to do as you say in the comment below but it seems there is no way to hightlight only a part of a string using ListBox. To me it seems the only control that is able to support that is the RichTextBox. A solution might be to implement your own user control in the form of a list of RichTextBoxes.
Building on #Thorsten Dittmar answer, I developed pretty much exactly what you are looking for in a single ListBox. You can find it at https://advancedlistbox.codeplex.com/.
It was pretty tough to think a title for this question so I'll try to make a better job explaining myself here.
I needed to create a dynamic Windows Form so that when checkbox gets checked/unchecked, few input fields appear/disappear. As far as I know FlowLayoutPanel seemed to be the best tool to achieve this. So I created a Custom User Control that included a Label and a Textbox. I designed this new Control in VS2013 desginer view:
Since the text on the label can vary in length it is important that textbox begins only when label has already ended. However the result I get at the moment looks like this:
The label should read out "ConnField" instead of "ConnFie". I tried adding these items in FlowLayoutPanel but that resulted in label and textbox not lining up correctly. Are there any attributes/properties that should be set in order to get the expected result? Should I use a container that does it all for me?
On a side note, if there are any other methods to dynamically show/hide elements in the fashion I described above I'd be very happy to use those instead.
For perfect fits you can script the TextChanged event(s) to make sure the TextBox always sits in place and keeps a nice size as well..
I have placed a Label and a TextBox into a Panel for testing. You will probaly not need or want the textBox1_TextChanged event but it was nice for testing..:
private void textBox1_TextChanged(object sender, EventArgs e)
{
label1.Text = textBox1.Text; // this is for testing
}
private void label1_TextChanged(object sender, EventArgs e)
{
textBox1.Left = label1.Right + 6; // <= this is what you need
textBox1.Width = panel2.Width - label1.Width - 8; // <= this is nice to have
}
Of course your offsets may vary..and obviously the Label has AutoSize = true
Edit
Since you commented on the problem of getting the TextBoxes aligned with each other across rows here are a few thoughts about this problem. As Hans noted, you can't have it all:
Complete freedom for the Labels' content
Perfect fits
And aligned Textboxes
The three goals conflict. So you need to make compromises:
If you can restrict the content to a fixed maximum, the result will look best
Sometimes it helps to have a collegue or even a user look at the content to find a shorter way to express the meaning
Ellipsis or abbreviations may help. I both cases you should set a ToolTip to show the full content
Another option is to switch to a narrower Font for some Labels
Instead of one fixed Label size maybe 2 or 3 will help: The look will be a bit jagged but will look a lot better than with completely free sizes.
In my WinForm application I have a multiline TextBox control (uiResults) which is used for reporting progress while processing a large number of items. Using AppendText works great for automatically scrolling to the bottom at every update, but if the user scrolls back to read some older data I need to turn off the autoscroll. I would rather stay away from P/Invoke calls if possible.
Is it possible to detect if the user has scrolled back without using P/Invoke? For now, I just check SelectionStart which works but requires the user to move the caret from the end of the textbox to stop the autoscroll:
if(uiResults.SelectionStart == uiResults.Text.Length)
{
uiResults.AppendText(result + Environment.NewLine);
}
My main problem is that when appending a string using the Text property, the textbox is scrolled to the beginning. I tried to solve this by storing the caret position and resetting and scrolling to it after the update, but this causes the current line to move to the bottom (of course, since ScrollToCaret scrolls no more than the necessary distance to bring the caret into view).
[Continued from above]
else
{
int pos = uiResults.SelectionStart;
int len = uiResults.SelectionLength;
uiResults.Text += result + Environment.NewLine;
uiResults.SelectionStart = pos;
uiResults.SelectionLength = len;
uiResults.ScrollToCaret();
}
Auto-scrolling text box uses more memory than expected
The code in the question implements exactly what you are looking for. Text is added, but scrolling only occurs if the scroll bar is at the very bottom.
I have had the same problem.
And finally, I made an easy way.
(Sorry, I'm not good at English.)
key point is get the first displayed char index using GetCharIndexFromPosition method.
//Get current infomation
int selStart = textBox.SelectionStart;
int selLen = textBox.SelectionLength;
int firstDispIndex = textBox.GetCharIndexFromPosition(new Point(3, 3));
//Append Text
textBox.AppendText(...);
//Scroll to original displayed position
textBox.Select(firstDispIndex, 0);
text.ScrolltoCaret();
//Restore original Selection
textBox.Select(selStart, selLen);
And, if textbox is flicking, use this extention.
Call textBox.Suspend() before adding text, and call textBox.Resume() after adding text.
namespace System.Windows.Forms
{
public static class ControlExtensions
{
[System.Runtime.InteropServices.DllImport("user32.dll")]
public static extern bool LockWindowUpdate(IntPtr hWndLock);
public static void Suspend(this Control control)
{
LockWindowUpdate(control.Handle);
}
public static void Resume(this Control control)
{
LockWindowUpdate(IntPtr.Zero);
}
}
}
Hope this will help you.
Thank you~
Are you open to another approach, because you are bound to get into trouble this way and the solutions will get complex (pinvoke etc. that you want to avoid). For eg. suppose you find a way to "detect if the user has scrolled back" and you stop scrolling to bottom. But after reading the line user might want the scroll to bottom feature to resume. So why not give user a way to control Auto-Scrolling. Here's how I would do it...
Use a RichTextBox to show data and a Checkbox to control AutoScrolling, then your code might be something like this:
richTextBox1.AppendText(result + Environment.NewLine);
if (checkBoxAutoScroll.Checked)
{
richTextBox1.SelectionStart = richTextBox1.Text.Length;
richTextBox1.ScrollToCaret();
}
RichTextBox by default will not automatically scroll to bottom on AppendText, so the first line would always be visible (and not the newly appended line). But if user checks this checkbox called AutoScroll, our code will then scroll the richtextbox to the bottom where new lines are shown. If user wants to manually scroll to read a line he will first need to uncheck the checkbox.