private static void WriteStringToReangle(Graphics gfx, SlantWatermark watermark, Rectangle rectangle)
{
string text = GetRepeatString(gfx, watermark.Text, watermark.Spacing, watermark.Font, rectangle.Width);
string alternateText = text.Substring(text.Length - watermark.Text.Length / 2) + watermark.Spacing + text;
int centerY = rectangle.Height / 2 + rectangle.Y;
gfx.DrawString(text, watermark.Font, watermark.Brush, rectangle.X, centerY);
bool alternate = true;
for (int pos = centerY - watermark.Indent; pos > rectangle.Y; pos -= watermark.Indent, alternate = !alternate)
{
gfx.DrawString(alternate ? alternateText : text, watermark.Font, watermark.Brush, rectangle.X, pos);
gfx.DrawString(alternate ? alternateText : text, watermark.Font, watermark.Brush, rectangle.X, centerY * 2 - pos);
}
}
public static Image Mark(Image originalImage, Image waterMark, SlantWatermark slantWatermark = null, TextUnderLogo textUnderLogo = null)
{
const int minWidthRate = 2;
const int minHeightRate = 3;
if (originalImage.Width / waterMark.Width < minWidthRate || originalImage.Height / waterMark.Height < minHeightRate)
{
return(new Bitmap(originalImage));
}
Image newImage = new Bitmap(originalImage);
using (Graphics gfx = Graphics.FromImage(newImage))
{
gfx.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
gfx.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
if (slantWatermark != null)
{
AddSlantWatermark(gfx, newImage.Width, newImage.Height, slantWatermark);
}
int marginBottom = 20;
int marginLeft = 20;
int logoMarginBottom = marginBottom;
if (textUnderLogo != null)
{
SizeF fontSize = gfx.MeasureString(textUnderLogo.Text, textUnderLogo.Font);
logoMarginBottom += (int)fontSize.Height;
gfx.DrawString(textUnderLogo.Text, textUnderLogo.Font, textUnderLogo.Brush,
originalImage.Width - fontSize.Width - marginLeft, originalImage.Height - fontSize.Height - marginBottom);
}
gfx.DrawImage(waterMark,
new Rectangle(originalImage.Width - waterMark.Width - marginLeft,
originalImage.Height - waterMark.Height - logoMarginBottom, waterMark.Width, waterMark.Height),
0, 0, waterMark.Width, waterMark.Height, GraphicsUnit.Pixel);
}
return(newImage);
}
private static void AddSlantWatermark(Graphics gfx, int width, int height, SlantWatermark watermark)
{
int watermarkWidth = Convert.ToInt32(height / 2.0 + Math.Sqrt(3) * width / 2);
int watermarkHeight = Convert.ToInt32(width / 2.0 + Math.Sqrt(3) * height / 2);
int centerX = Convert.ToInt32(width / 2);
int centerY = Convert.ToInt32(height / 2);
Rectangle rectangle = new Rectangle(centerX - watermarkWidth / 2, centerY - watermarkHeight / 2, watermarkWidth, watermarkHeight);
gfx.TranslateTransform(centerX, centerY);
gfx.RotateTransform(-30);
gfx.TranslateTransform(-centerX, -centerY);
WriteStringToReangle(gfx, watermark, rectangle);
gfx.ResetTransform();
}
public static void Mark(string originImagePath, string watermarkImagePath, string outputFolder, SlantWatermark slantWatermark = null, TextUnderLogo textUnderLogo = null)
{
string fileName = Path.GetFileName(originImagePath);
Mark(originImagePath, watermarkImagePath, outputFolder, fileName, slantWatermark, textUnderLogo);
}
public static void Mark(string originImagePath, string watermarkImagePath, string outputFolder, string fileName, SlantWatermark slantWatermark = null, TextUnderLogo textUnderLogo = null)
{
if (!Directory.Exists(outputFolder))
{
Directory.CreateDirectory(outputFolder);
}
string newImagePath = Path.Combine(outputFolder, fileName);
Image newImage;
using (Image originImage = Image.FromFile(originImagePath)
, watermarkImage = Image.FromFile(watermarkImagePath))
{
newImage = Mark(originImage, watermarkImage, slantWatermark, textUnderLogo);
}
//放在这里确保newImagePath与originImagePath相同时能正常保存
newImage.Save(newImagePath, ImageFormat.Jpeg);
newImage.Dispose();
}
