How to use API to calculate the width and height of a Label's caption?

[yfhao]

I'm a VB beginner, I know how to use the TextWidth and TextHeight of a Form or Picturebox, but I don't know how to use API to calculate the width and height of a Label's caption.

[LaVolpe]

This isn't a straightforward type of question, nor answer.

First, labels have a width and height property. Granted that doesn't give you the space required for the actual text. And if the label is allowed to wordwrap, things can get complicated more quickly.

Maybe you can give more details to what you are trying to do? Otherwise, look at these APIs & VB examples for: GetTextExtentPoint32 & DrawText

[Elroy]

If it were me, I'd "borrow" the form's TextWidth and TextHeight methods to figure it out.

[yfhao]

This isn't a straightforward type of question, nor answer.

First, labels have a width and height property. Granted that doesn't give you the space required for the actual text. And if the label is allowed to wordwrap, things can get complicated more quickly.

Maybe you can give more details to what you are trying to do? Otherwise, look at these APIs & VB examples for: GetTextExtentPoint32 & DrawText

If it were me, I'd "borrow" the form's TextWidth and TextHeight methods to figure it out.

Thank you, LaVolpe and Elroy.

My current approach is this:

Private Sub Command3_Click()
Dim FontName As String:     Dim FontSize As Single
Dim FontBold As Boolean

With Me
    FontName = .FontName
    FontSize = .FontSize
    FontBold = .FontBold
    
    .FontName = Label1.FontName
    .FontSize = Label1.FontSize
    .FontBold = Label1.FontBold
    
    MsgBox .TextWidth(Label1.Caption)
    
    .FontName = FontName
    .FontSize = FontSize
    .FontBold = FontBold
End With
    
End Sub

I hope to achieve the following function:

Public Function getTextWidth(objFont As StdFont, Text As String) As Single

End Function

[DataMiser]

If memory serves there is an auto size property for labels. You could in theory have a label that is not visible and set to auto and may be able to get the size from that.

[LaVolpe]

I hope to achieve the following function:

Public Function getTextWidth(objFont As StdFont, Text As String) As Single

End Function

If the string to be measured is for display on a form/control, maybe also pass along to your function a VB object with a hDC property, i.e., the form, a picbox, etc. Then steps are truly simple, no APIs needed

- cache original font in passed hDC object, i.e., Set tmpFont = passedObj.Font
- put passed font into that object: Set passedObj.Font = objFont
- use TextWidth,TextHeight as needed
- replace original font: Set passedObj.Font = tmpFont

[Elroy]

And this was suppose to be added to post #3, but I was trying to add it just as the forums went down for maintenance.

Something like the following (a default Form1, with a single Label1 on it):

Option Explicit

Private Sub Form_Load()
    Label1.Caption = "asdf asdf asdf asdf asdf asdf asdf asdf"
End Sub

Private Sub Label1_Click()
    Dim fnt As StdFont
    Dim sc As Long
    Dim w As Long
    Dim h As Long
    '
    Set fnt = Form1.Font                    ' Save form's Font so we can put it back.
    sc = Form1.ScaleMode                    ' Save form's ScaleMode so we can put it back.
    Set Form1.Font = Label1.Font            ' Set form's font to caption's font.
    Form1.ScaleMode = vbTwips               ' We'll get/report things in twips.
    '
    w = Form1.TextWidth(Label1.Caption)     ' Get width.
    h = Form1.TextHeight(Label1.Caption)    ' Get height.
    '
    Form1.ScaleMode = sc                    ' Put back ScaleMode.
    Set Form1.Font = fnt                    ' Put back Font.
    '
    MsgBox "In twips, Label1's width is " & Format$(w) & " and its height is " & Format$(h) & "."
End Sub

Now, this won't account for any WordWrap in the Label1. That's an entirely different problem.

Also, you could have specified the units in the TextWidth/TextHeight calls, rather than the way I did it, but 6-of-one-half-dozen-of-another.

Enjoy,
Elroy

[yfhao]

If memory serves there is an auto size property for labels. You could in theory have a label that is not visible and set to auto and may be able to get the size from that.

AutoSize seems to be a good solution, but it only works with VB.Lable, not for TextBox and CommandButton.

[yfhao]

If the string to be measured is for display on a form/control, maybe also pass along to your function a VB object with a hDC property, i.e., the form, a picbox, etc. Then steps are truly simple, no APIs needed

- cache original font in passed hDC object, i.e., Set tmpFont = passedObj.Font
- put passed font into that object: Set passedObj.Font = objFont
- use TextWidth,TextHeight as needed
- replace original font: Set passedObj.Font = tmpFont

Thank you for your reply!

[yfhao]

And this was suppose to be added to post #3, but I was trying to add it just as the forums went down for maintenance.

Something like the following (a default Form1, with a single Label1 on it):

Option Explicit

Private Sub Form_Load()
    Label1.Caption = "asdf asdf asdf asdf asdf asdf asdf asdf"
End Sub

Private Sub Label1_Click()
    Dim fnt As StdFont
    Dim sc As Long
    Dim w As Long
    Dim h As Long
    '
    Set fnt = Form1.Font                    ' Save form's Font so we can put it back.
    sc = Form1.ScaleMode                    ' Save form's ScaleMode so we can put it back.
    Set Form1.Font = Label1.Font            ' Set form's font to caption's font.
    Form1.ScaleMode = vbTwips               ' We'll get/report things in twips.
    '
    w = Form1.TextWidth(Label1.Caption)     ' Get width.
    h = Form1.TextHeight(Label1.Caption)    ' Get height.
    '
    Form1.ScaleMode = sc                    ' Put back ScaleMode.
    Set Form1.Font = fnt                    ' Put back Font.
    '
    MsgBox "In twips, Label1's width is " & Format$(w) & " and its height is " & Format$(h) & "."
End Sub

Now, this won't account for any WordWrap in the Label1. That's an entirely different problem.

Also, you could have specified the units in the TextWidth/TextHeight calls, rather than the way I did it, but 6-of-one-half-dozen-of-another.

Enjoy,
Elroy

Thank you for your reply!

[DataMiser]

AutoSize seems to be a good solution, but it only works with VB.Lable, not for TextBox and CommandButton.

Yes that is true but the question here was about a label without mention of any other type of control.