问题
I have a label that shows the file name .. I had to set AutoSize of the label to False for designing.
So when the file name text got longer than label size.. it got cut like in the picture.
label1.Size = new Size(200, 32);
label1.AutoSize = false;
How do I re-size the text automatically to fit the label size, when the text is longer than the label size?
回答1:
You can use my code snippet below. System needs some loops to calculate the label's font based on text size.
while(label1.Width < System.Windows.Forms.TextRenderer.MeasureText(label1.Text,
new Font(label1.Font.FontFamily, label1.Font.Size, label1.Font.Style)).Width)
{
label1.Font = new Font(label1.Font.FontFamily, label1.Font.Size - 0.5f, label1.Font.Style);
}
回答2:
Label scaling
private void scaleFont(Label lab)
{
Image fakeImage = new Bitmap(1, 1); //As we cannot use CreateGraphics() in a class library, so the fake image is used to load the Graphics.
Graphics graphics = Graphics.FromImage(fakeImage);
SizeF extent = graphics.MeasureString(lab.Text, lab.Font);
float hRatio = lab.Height / extent.Height;
float wRatio = lab.Width / extent.Width;
float ratio = (hRatio < wRatio) ? hRatio : wRatio;
float newSize = lab.Font.Size * ratio;
lab.Font = new Font(lab.Font.FontFamily, newSize, lab.Font.Style);
}
TextRenderer Approach pointed out by @ToolmakerSteve in the comments
private void ScaleFont(Label lab)
{
SizeF extent = TextRenderer.MeasureText(lab.Text, lab.Font);
float hRatio = lab.Height / extent.Height;
float wRatio = lab.Width / extent.Width;
float ratio = (hRatio < wRatio) ? hRatio : wRatio;
float newSize = lab.Font.Size * ratio;
lab.Font = new Font(lab.Font.FontFamily, newSize, lab.Font.Style);
}
回答3:
Based on the article provided by @brgerner, I'll provide the alternative implementation here, as that one marked as an answer is not so efficient nor complete as this one below:
public class FontWizard
{
public static Font FlexFont(Graphics g, float minFontSize, float maxFontSize, Size layoutSize, string s, Font f, out SizeF extent)
{
if (maxFontSize == minFontSize)
f = new Font(f.FontFamily, minFontSize, f.Style);
extent = g.MeasureString(s, f);
if (maxFontSize <= minFontSize)
return f;
float hRatio = layoutSize.Height / extent.Height;
float wRatio = layoutSize.Width / extent.Width;
float ratio = (hRatio < wRatio) ? hRatio : wRatio;
float newSize = f.Size * ratio;
if (newSize < minFontSize)
newSize = minFontSize;
else if (newSize > maxFontSize)
newSize = maxFontSize;
f = new Font(f.FontFamily, newSize, f.Style);
extent = g.MeasureString(s, f);
return f;
}
public static void OnPaint(object sender, PaintEventArgs e, string text)
{
var control = sender as Control;
if (control == null)
return;
control.Text = string.Empty; //delete old stuff
var rectangle = control.ClientRectangle;
using (Font f = new System.Drawing.Font("Microsoft Sans Serif", 20.25f, FontStyle.Bold))
{
SizeF size;
using (Font f2 = FontWizard.FlexFont(e.Graphics, 5, 50, rectangle.Size, text, f, out size))
{
PointF p = new PointF((rectangle.Width - size.Width) / 2, (rectangle.Height - size.Height) / 2);
e.Graphics.DrawString(text, f2, Brushes.Black, p);
}
}
}
}
and the usage:
val label = new Label();
label.Paint += (sender, e) => FontWizard.OnPaint(sender, e, text);
回答4:
I use the following weighted scaling trick to provide a good fit, i.e. a weighted tradeoff is made between fitting the height and fitting the width. It's in VB .net, but I think you can translate to C# easily.
Function shrinkFontToFit(f As Font, text As String, requiredsize As SizeF) As Font
Dim actualsize As SizeF = TextRenderer.MeasureText(text, f)
Return New Font(f.FontFamily, f.Size * (requiredsize.Width + requiredsize.Height ) _
/ (actualsize.Width + actualsize.Height), f.Style, GraphicsUnit.Pixel)
End Function
回答5:
With inspiration from @bnguyen82 i came up with something that works all the way.
public static void ScaleLabel(Label label, float stepSize = 0.5f)
{
//decrease font size if text is wider or higher than label
while (lblTextSize() is Size s && s.Width > label.Width || s.Height > label.Height)
{
label.Font = new Font(label.Font.FontFamily, label.Font.Size - stepSize, label.Font.Style);
}
//increase font size if label width is bigger than text size
while (label.Width > lblTextSize().Width)
{
var font = new Font(label.Font.FontFamily, label.Font.Size + stepSize, label.Font.Style);
var nextSize = TextRenderer.MeasureText(label.Text, font);
//dont make text width or hight bigger than label
if (nextSize.Width > label.Width || nextSize.Height > label.Height)
break;
label.Font = font;
}
Size lblTextSize() => TextRenderer.MeasureText(label.Text,
new Font(label.Font.FontFamily, label.Font.Size, label.Font.Style));
}
PS: In order for this to work the label needs to have AutoSize = false and either to be docked or anchored.
回答6:
I think the easiest way could be to check the render size and if it is greater than the actual label size, decrease the fontsize of the label.
private void label3_Paint(object sender, PaintEventArgs e) {
Size sz = TextRenderer.MeasureText(label1.Text, label1.Font, label1.Size, TextFormatFlags.WordBreak);
if (sz.Width > label1.Size.Width || sz.Height > label1.Size.Height)
{
DecreaseFontSize(label1);
}
}
public void DecreaseFontSize(Label lbl) {
lbl.Font = new System.Drawing.Font(lbl.Font.Name, lbl.Font.Size - 1, lbl.Font.Style);
}
回答7:
private void setFontSize(Label label1)
{
if (label1.Text.Length > 200)
{
label1.Font = new Font(label1.Font.FontFamily, 24f, label1.Font.Style);
}
else if (label1.Text.Length > 100)
{
label1.Font= new Font(label1.Font.FontFamily, 36f, label1.Font.Style);
}
else
label1.Font = new Font(label1.Font.FontFamily, 48f, label1.Font.Style);//My orginal font size is 48f.
}
You can edit for yourself.
private void button1_Click(object sender, EventArgs e)
{
Panel.Text = "Your Text";
setFontSize(Panel);
}
来源：https://stackoverflow.com/questions/9527721/resize-text-size-of-a-label-when-the-text-gets-longer-than-the-label-size