Initially Empty Labels

[cindy2]

Hi,

In my vb2005-project I have a x by x array as type double. To visualise what's in it, I connected each index to a label. When I run the programm, the initial array is empty, so each label contains a zero.

The problem I have is, I don't wanna see all the zero's initially (on runtime). I only want to see the labels if I put a zero (or another number) in the array. Is there an easy way to do this?

Cindy

[Killer42]

(Caveat: I'm a VB6 developer so may be talking garbage...)

Can you explain what you mean by "connecting each index to a label"? Or is this too obvious in VB2005 to explain?

[cindy2]

(Caveat: I'm a VB6 developer so may be talking garbage...)

Can you explain what you mean by "connecting each index to a label"? Or is this too obvious in VB2005 to explain?

Hi,

Yes, it's very obvious in vb2005 :). Let's say I have an array with 4 by 4 elements, which gives a total of 16 elements. Now, on my design-form I put 16 labels. Each of these labels is connected to an index of the array:

label1.text = Arr(0, 0)    'first colomn
label2.text = Arr(1, 0)
label3.text = Arr(2, 0)
label4.text = Arr(3, 0)
label5.text = Arr(1, 1)   'second column
label6.text = Arr(2, 1)
....etc.
Label16.text = Arr(3, 3)

I hope this explains what you mean, because on the other hand, I don't know VB6.

Cindy

[cugone]

Depending on the legal range of numbers you want, just put a number outside said range and check for not that number. EX:

Your legal range is zero or above:

'This can also be accomplished by setting each label in the Propeties tab on the
'Designer page (select them all, set the Text Prop to -1.0).

label1.text = "-1.0"
label2.text = "-1.0"
...
label16.text = "-1.0"

.....
dim i as double = 0.0
dim j as double = 0.0

for each allControls in me.Controls
     if (typeof allControls is label) then
          if Convert.toDouble(allControls.text) >= 0.0 then
               allControls.text = array(i,j).tostring
          end if
     end if
     i += 1
     j += 1
next

[cindy2]

Depending on the legal range of numbers you want, just put a number outside said range and check for not that number. EX:

Your legal range is zero or above:

'This can also be accomplished by setting each label in the Propeties tab on the
'Designer page (select them all, set the Text Prop to -1.0).

label1.text = "-1.0"
label2.text = "-1.0"
...
label16.text = "-1.0"

.....
dim i as double = 0.0
dim j as double = 0.0

for each allControls in me.Controls
     if (typeof allControls is label) then
          if Convert.toDouble(allControls.text) >= 0.0 then
               allControls.text = array(i,j).tostring
          end if
     end if
     i += 1
     j += 1
next

Thank you for your reply. I'm sorry, but I don't understand. I know the code you have written is specific, but I'm afraid it's not specific enough for me. I tried some things with your code, but it does not give the results I want.

For example: Is the array of type data or string?

Cindy

[Killer42]

Yes, it's very obvious in vb2005 :). Let's say I have an array with 4 by 4 elements, which gives a total of 16 elements. Now, on my design-form I put 16 labels. Each of these labels is connected to an index of the array:

label1.text = Arr(0, 0)    'first colomn
label2.text = Arr(1, 0)
label3.text = Arr(2, 0)
label4.text = Arr(3, 0)
label5.text = Arr(1, 1)   'second column
label6.text = Arr(2, 1)
....etc.
Label16.text = Arr(3, 3)

So, in other words, there isn't any sort of connection between them. You just copied the values from the array into the labels.

Which means the reason there are zeroes there is that you put them there. Which in turn means that the solution is obvious - don't! :)

For example...
[CODE=vbnet]If Arr(1, 0) Then
label2.text = Arr(1, 0)
End If[/CODE](This is taking advantage of the fact that any non-zero value will evaluate to True in an IF. If you want, you could also say If Arr(1, 0) <> 0 Then.)

Of course, I wouldn't code this IF test 16 times. It'd make for nicer code to do something like creating a function that returns a string containing the number only if it's non-zero. For the sake of argument, let's say you called the function BlankIfZero. Then you could say...
[CODE=vbnet]label1.text = BlankIfZero(Arr (0, 0)) 'first colomn
label2.text = BlankIfZero(Arr (1, 0))
label3.text = BlankIfZero(Arr (2, 0))
label4.text = BlankIfZero(Arr (3, 0))
label5.text = BlankIfZero(Arr (1, 1)) 'second column
label6.text = BlankIfZero(Arr (2, 1))[/CODE]

[cindy2]

For example...
[CODE=vbnet]If Arr(1, 0) Then
label2.text = Arr(1, 0)
End If[/CODE](This is taking advantage of the fact that any non-zero value will evaluate to True in an IF. If you want, you could also say If Arr(1, 0) <> 0 Then.)

Of course, I wouldn't code this IF test 16 times. It'd make for nicer code to do something like creating a function that returns a string containing the number only if it's non-zero. For the sake of argument, let's say you called the function BlankIfZero. Then you could say...
[CODE=vbnet]label1.text = BlankIfZero(Arr (0, 0)) 'first colomn
label2.text = BlankIfZero(Arr (1, 0))
label3.text = BlankIfZero(Arr (2, 0))
label4.text = BlankIfZero(Arr (3, 0))
label5.text = BlankIfZero(Arr (1, 1)) 'second column
label6.text = BlankIfZero(Arr (2, 1))[/CODE]

Thanks for your reply,

I only want to "hide' the zero's initially at runtime. So it must still be possible to put a zero in the array and then copy it to the corresponding label. Is that also possible with your approach?

Cindy

[Killer42]

I only want to "hide' the zero's initially at runtime. So it must still be possible to put a zero in the array and then copy it to the corresponding label. Is that also possible with your approach?

Sure. Since your code is putting the zeroes in there, you can do it or skip it any time you like.

One simple technique would be to create a global Boolean variable. Let's call it ThisIsNotTheFir stTime, just for fun. At the end of the segment of code which sets the labels, you set it to True.

Then, in the BlankIfZero function, you'd do something like...

[CODE=vb]Public Function BlankIfZero(ByV al TheNumber As Long) As String
If (TheNumber <> 0) Or ThisIsNotTheFir stTime Then
BlankIfZero = TheNumber
End If
End Function[/CODE]

You just have to use a bit of imagination. :)

[cindy2]

Sure. Since your code is putting the zeroes in there, you can do it or skip it any time you like.

You just have to use a bit of imagination. :)

Thank you, it does work fine, but I still have a problem. The labels are initially empty, but when I want to put a number in the array, that then is copied to a label, I have to go through all the 'code' that copies the array-indexes to the labels. This is because in the first instance I don't know which index must be copied to the corresponding label. So all the zero's will be visible (again). My code looks something like this:

If Arr1(j) = Arr2(i) Then                           
          Array(i, column) = Arr3(j)      ' "Array" is the array we are talking about
End If

And as mentioned, next I have to copy the indexnumbers to the labels:
[CODE=vbnet]
label1.text = BlankIfZero(Arr ay(0, 0)) 'first colomn
label2.text = BlankIfZero(Arr ay(1, 0))
label3.text = BlankIfZero(Arr ay(2, 0))
label4.text = BlankIfZero(Arr ay(3, 0))
label5.text = BlankIfZero(Arr ay(1, 1)) 'second column
label6.text = BlankIfZero(Arr ay(2, 1))
........etc.
label16.text = BlankIfZero(Arr ay(3, 3))
[/CODE]

I really tried to use my imagination, but I can't figure it out how to 'hide' the initial zero's when I change the array. Do you have some advice for me?

Cindy

[Killer42]

Um... I think someone else posted a solution earlier in this thread which might help. That is, pick some value that won't show up in the real data, and initialise all your array entries with that value. For example, set them all to -999.

Then, every time you copy them to the labels, you show whatever value is there, unless it's -999. That way, if a zero does turn up, it will be displayed.

What do you think? I can't say for sure, as I don't know your data.

[QVeen72]

Hi,

Declare the Array as a Variant.. say :
Dim MyArr(4,4)

Do not write as Double.. (or whatever)
This is Because, when you declare an Array as some type, All the Array items will be Initialized to default Value (0 for numeric, Blank String for Strings, False For Boolean). With Variant, All of the Array Items wud be Empty.. And Non-Initialized items will show as blank in the Label..
And will work for your problem..
Write one Common Procedure To Populate the Labels with array Values.
And whenevr, Array items are Manipulated, call that Procedure.

Regards
Veena

[cindy2]

Hi,

Declare the Array as a Variant.. say :
Dim MyArr(4,4)

Do not write as Double.. (or whatever)
This is Because, when you declare an Array as some type, All the Array items will be Initialized to default Value (0 for numeric, Blank String for Strings, False For Boolean). With Variant, All of the Array Items wud be Empty.. And Non-Initialized items will show as blank in the Label..
And will work for your problem..
Write one Common Procedure To Populate the Labels with array Values.
And whenevr, Array items are Manipulated, call that Procedure.

Regards
Veena

Thank you for your reply,
It does work, all the labels are blank initially. And when I put a number in the array, the corresponding label will visualize it.

Another part of the programm adds all the row ellements of the array. Because of the 'variant' type, the programm tries to add string-elements (the elements of the array that haven't been populated yet), so an error occured. I tried to convert the type of the array to single for that part of programm, but that didn't work. Do you have a suggestion?

Cindy

[QVeen72]

Hi,

use Val Function
Some thing like this :

TArr(1,2) = Val(TArr(2,3)) + Val(TArr(2,4))

Regards
Veena

[cindy2]

Thank you all!!!
It works great! :)

[Killer42]

Thank you all!!!
It works great! :)

Excellent!

Good work, team. :)