如何在运行时从文本生成图像

Question

任何人都可以指导如何从输入文本生成图像。图片可能有任何扩展名并不重要。在影像上呈现文本

Answer 1

好吧，假设你想绘制在C＃中的图像上的绳子，你将需要在这里使用System.Drawing命名空间：

private Image DrawText(String text, Font font, Color textColor, Color backColor) 
{ 
    //first, create a dummy bitmap just to get a graphics object 
    Image img = new Bitmap(1, 1); 
    Graphics drawing = Graphics.FromImage(img); 

    //measure the string to see how big the image needs to be 
    SizeF textSize = drawing.MeasureString(text, font); 

    //free up the dummy image and old graphics object 
    img.Dispose(); 
    drawing.Dispose(); 

    //create a new image of the right size 
    img = new Bitmap((int) textSize.Width, (int)textSize.Height); 

    drawing = Graphics.FromImage(img); 

    //paint the background 
    drawing.Clear(backColor); 

    //create a brush for the text 
    Brush textBrush = new SolidBrush(textColor); 

    drawing.DrawString(text, font, textBrush, 0, 0); 

    drawing.Save(); 

    textBrush.Dispose(); 
    drawing.Dispose(); 

    return img; 

} 

此代码将先测量串，然后创建一个正确大小的图像。

如果你想保存这个函数的返回值，只需调用返回图像的Save方法即可。

Answer 2

使用imagemagick（在服务器上）

既然你是在C＃中，你也可以使用直接位图和字体操纵的.NET类（使用类，如：System.Drawing.Bitmap和System.Drawing.Graphics）

Answer 3

我刚刚将此answer中提到的这种方法转换为VB.NET方法。也许这有助于某人。

Public Function DrawText(ByVal text As String, ByRef font As Font, ByRef textColor As Color, ByRef backColor As Color) As Image 
    ' first, create a dummy bitmap just to get a graphics object 
    Dim img As Image = New Bitmap(1, 1) 
    Dim drawing As Graphics = Graphics.FromImage(img) 

    ' measure the string to see how big the image needs to be 
    Dim textSize As SizeF = drawing.MeasureString(Text, Font) 

    ' free up the dummy image and old graphics object 
    img.Dispose() 
    drawing.Dispose() 

    ' create a new image of the right size 
    img = New Bitmap(CType(textSize.Width, Integer), CType(textSize.Height, Integer)) 

    drawing = Graphics.FromImage(img) 

    ' paint the background 
    drawing.Clear(BackColor) 

    ' create a brush for the text 
    Dim textBrush As Brush = New SolidBrush(textColor) 

    drawing.DrawString(text, font, textBrush, 0, 0) 

    drawing.Save() 

    textBrush.Dispose() 
    drawing.Dispose() 

    Return img 

End Function 

编辑：固定错字。

Answer 4

F#版本：

open System.Drawing 

let drawText text font textColor backColor = 
    let size = 
     use dummyImg = new Bitmap(1, 1) 
     use drawing = Graphics.FromImage(dummyImg) 
     drawing.MeasureString(text, font) 
    let img = new Bitmap((int size.Width), (int size.Height)) 
    use drawing = Graphics.FromImage(img) 
    use textBrush = new SolidBrush(textColor) 
    do 
     drawing.Clear(backColor) 
     drawing.DrawString(text, font, textBrush, PointF()) 
     drawing.Save() |> ignore 
    img 

Answer 5

感谢Kazar。以前的答案的略有改善使用使用使用后的图像/图形对象的

private Image DrawTextImage(String currencyCode, Font font, Color textColor, Color backColor) { 
     return DrawTextImage(currencyCode, font, textColor, backColor, Size.Empty); 
    } 
    private Image DrawTextImage(String currencyCode, Font font, Color textColor, Color backColor, Size minSize) { 
     //first, create a dummy bitmap just to get a graphics object 
     SizeF textSize; 
     using (Image img = new Bitmap(1, 1)) { 
      using (Graphics drawing = Graphics.FromImage(img)) { 
       //measure the string to see how big the image needs to be 
       textSize = drawing.MeasureString(currencyCode, font); 
       if (!minSize.IsEmpty) { 
        textSize.Width = textSize.Width > minSize.Width ? textSize.Width : minSize.Width; 
        textSize.Height = textSize.Height > minSize.Height ? textSize.Height : minSize.Height; 
       } 
      } 
     } 

     //create a new image of the right size 
     Image retImg = new Bitmap((int)textSize.Width, (int)textSize.Height); 
     using (var drawing = Graphics.FromImage(retImg)) { 
      //paint the background 
      drawing.Clear(backColor); 

      //create a brush for the text 
      using (Brush textBrush = new SolidBrush(textColor)) { 
       drawing.DrawString(currencyCode, font, textBrush, 0, 0); 
       drawing.Save(); 
      } 
     } 
     return retImg; 
    }