C#中使用GDI 让网站新闻标题个性化

新华网上的“今日头条”的标题是用图片体现的。这种头条我们一般的做法可能是：使用Photoshop制作成图片，保存上传。这样需要浪费人力，比较麻烦。有没有更好的办法呢？

下面使用GDI+及C#代码，完成自动实现的过程。

老规矩，先看看运行效果：

下面是C#代码：

				
// Text2Image.aspx
// Text2Image.aspx.cs
using System; 
using System.Data; 
using System.Configuration; 
using System.Collections; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 
using System.Drawing; 
using System.Drawing.Imaging; 
using System.Drawing.Drawing2D; 
using System.IO; 
				
namespace BrawDraw.Com.Utility
{
public partial class Utility_Text2Image : System.Web.UI.Page
{
int _width = 480; 
public int Width
{
get
{
return _width; 
}
set
{
_width = value; 
}
}
				
int _height = 66; 
public int Height
{
get
{
return _height; 
}
set
{
_height = value; 
}
}
				
string _text = string.Empty; 
public string Text
{
get
{
return _text; 
}
set
{
_text = value; 
}
}
				
string _fontName = "宋体"; 
public string FontName
{
get
{
return _fontName; 
}
set
{
_fontName = value; 
}
}
				
Color _fontColor = Color.Black; 
public Color FontColor
{
get
{
return _fontColor; 
}
set
{
_fontColor = value; 
}
}
				
Color _backgroundColor = Color.White; 
public Color BackgroundColor
{
get
{
return _backgroundColor; 
}
set
{
_backgroundColor = value; 
}
}
				
//华文新魏
protected void Page_Load(object sender, EventArgs e)
{
if (Request.QueryString["w"] != null)
{
try
{
this._width = int.Parse(Request.QueryString["w"].Trim()); 
}
finally
{
}
}
				
if (Request.QueryString["h"] != null)
{
try
{
this._height = int.Parse(Request.QueryString["h"].Trim()); 
}
finally
{
}
}
				
if (Request.QueryString["text"] != null)
{
this._text = Request.QueryString["text"].Trim(); 
}
else if (Request.QueryString["t"] != null)
{
this._text = Request.QueryString["t"].Trim(); 
}
				
if (Request.QueryString["font"] != null)
{
this._fontName = Request.QueryString["font"].Trim(); 
}
else if (Request.QueryString["f"] != null)
{
this._fontName = Request.QueryString["f"].Trim(); 
}
if (this._fontName == "大黑")
{
this._fontName = "方正大黑简体"; 
}
string colorString = "Black"; 
if (Request.QueryString["color"] != null)
{
colorString = Request.QueryString["color"].Trim(); 
}
else if (Request.QueryString["c"] != null)
{
colorString = Request.QueryString["c"].Trim(); 
}
if (colorString.StartsWith("_"))
{
colorString = "#" + colorString.Remove(0, 1); 
}
this._fontColor = ConvertColor(colorString); 
				
string bgColorString = "White"; 
if (Request.QueryString["bgcolor"] != null)
{
bgColorString = Request.QueryString["bgcolor"].Trim(); 
}
else if (Request.QueryString["b"] != null)
{
bgColorString = Request.QueryString["b"].Trim(); 
}
if (bgColorString.StartsWith("_"))
{
bgColorString = "#" + bgColorString.Remove(0, 1); 
}
				
this._backgroundColor = ConvertColor(bgColorString); 
				
if (!IsPostBack)
{
CreateImage(this.Text, this.Width, this.Height, this.FontName, this.FontColor, this.
				
BackgroundColor); 
}
}
				
//根据验证字符串生成最终图象
public void CreateImage(string text, int width, int height, string fontName, Color
				
fontColor, Color backgroundColor)
{
Bitmap theBitmap = new Bitmap(width, height); 
Graphics theGraphics = Graphics.FromImage(theBitmap); 
theGraphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic; 
theGraphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality; 
theGraphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; 
theGraphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias; 
// 背景
theGraphics.Clear(backgroundColor); 
				
GraphicsPath gp = new GraphicsPath(); 
FontFamily fontFamily; 
try
{
fontFamily = new FontFamily(fontName); 
}
catch (Exception exc)
{
fontFamily = new FontFamily("宋体"); 
}
StringFormat format = new StringFormat(); 
format.Alignment = StringAlignment.Near; 
format.LineAlignment = StringAlignment.Center; 
				
gp.AddString(text, fontFamily, 0, 60f, new Point(0, 0), format); 
RectangleF rectF = gp.GetBounds(); 
float scaleX = width * 1.0f / rectF.Width; 
float scaleY = height * 1.0f / rectF.Height; 
float offsetX = rectF.X * scaleX; 
float offsetY = rectF.Y * scaleY; 
System.Drawing.Drawing2D.Matrix matrix = new Matrix(scaleX, 0, 0, scaleY, 
				
-offsetX, -offsetY); 
gp.Transform(matrix); 
Brush newBrush = new SolidBrush(fontColor); 
theGraphics.FillPath(newBrush, gp); 
//theGraphics.DrawRectangle(Pens.Black, 0, 0, width-2, height-2); 
				
if (gp != null) gp.Dispose(); 
				
// 将生成的图片发回客户端
MemoryStream ms = new MemoryStream(); 
theBitmap.Save(ms, ImageFormat.Png); 
				
Response.ClearContent(); //需要输出图象信息 要修改HTTP头 
Response.ContentType = "image/Png"; 
Response.BinaryWrite(ms.ToArray()); 
theGraphics.Dispose(); 
theBitmap.Dispose(); 
Response.End(); 
}
				
private Color ConvertColor(string colorString)
{
Array knownColors = System.Enum.GetValues(typeof(KnownColor)); 
foreach (object colorName in knownColors)
{
if (colorString.ToLower() == colorName.ToString().ToLower())
{
return Color.FromName(colorString); 
}
}
				
if (colorString.StartsWith("#"))
{
return ColorTranslator.FromHtml(colorString); 
}
				
try
{
int color32argb = int.Parse(colorString); 
return Color.FromArgb(color32argb); 
}
finally
{ }
				
return Color.Black; 
}
}
}
		

调用方法：

BrawDraw.Com在线生成个性化标题
(其中text后面传入要显示的文字，w或width参数设置图片宽度，h或height设置图片高度，f或font设置字体，c或color设置标题的颜色。)

OK，大功告成。

如果你是使用静态网页，你可以使用Javascript方式嵌入：

显示效果图：

或许，你的服务器上没有安装你设置的字体（关于如何取得服务器上已安装字体列表，详见这篇：http://blog.csdn.net/johnsuna/archive/2008/04/14/2290744.aspx），比如下面代码：

正常的显示应该是这样：

如果没有此字体显示出来的效果就是这样：

原因在于我在下面代码中设置了没有该字体时，则会执行至catch (Exception exc)块内，