/// <summary>
/// 设置水印
/// </summary>
/// <param name="original"></param>
/// <param name="watermark"></param>
/// <returns></returns>
public Image MakeWatermark(Image original, Watermark watermark)
{
//Bitmap b = new Bitmap(original.Width, original.Height, PixelFormat.Format24bppRgb);
//b.SetResolution(original.HorizontalResolution, original.VerticalResolution);
// 不加水印
if (watermark.Ratio < 0)
{
return(original);
}
//当ratio大于1时，加的部分水印会在图片外面(不显示)
Size markSize = new Size((int)Math.Round(watermark.Ratio * original.Width), (int)Math.Round(watermark.Ratio * original.Height));
watermark.SetSize(markSize);
switch (watermark.WatermarkType)
{
case WatermarkType.Text:
//添加文字水印
var textWm = watermark as TextWatermark;
if (!string.IsNullOrEmpty(textWm.Text))
{
textWm.HorizontalResolution = original.HorizontalResolution; // b.HorizontalResolution;
textWm.VerticalResolution = original.VerticalResolution; // b.VerticalResolution;
var textMark = this.CreateTextWatermark(textWm);
ImageWatermark imageWm = new ImageWatermark()
{
Alignment = textWm.Alignment,
Alpha = textWm.Alpha,
Image = textMark,
MarginPercentage = textWm.MarginPercentage,
Ratio = textWm.Ratio,
};
imageWm.SetSize(textWm.Size);
return(MakeImageWatermark(original, imageWm));
}
break;
case WatermarkType.Image:
return(MakeImageWatermark(original, watermark as ImageWatermark));
break;
default:
break;
}
return(original);
}
/// <summary>
///
/// </summary>
/// <param name="watermark"></param>
/// <returns></returns>
protected Image MakeImageWatermark(Image original, ImageWatermark watermark)
{
ImageAttributes imageAttributes = new ImageAttributes();
ColorMap colorMap = new ColorMap();
colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);
colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);
ColorMap[] remapTable = { colorMap, };
imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);
var alpha = watermark.Alpha;
float[][] colorMatrixElements =
{
new float[] { 1.0f, 0.0f, 0.0f, 0.0f, 0.0f }, //red
new float[] { 0.0f, 1.0f, 0.0f, 0.0f, 0.0f }, //green
new float[] { 0.0f, 0.0f, 1.0f, 0.0f, 0.0f }, //blue
new float[] { 0.0f, 0.0f, 0.0f, alpha, 0.0f }, //alpha
new float[] { 0.0f, 0.0f, 0.0f, 0.0f, 1.0f }, //P
};
ColorMatrix colorMatrix = new ColorMatrix(colorMatrixElements);
imageAttributes.SetColorMatrix(colorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
int xpos = 0;
int ypos = 0;
int markWidth = 0;
int markHeight = 0;
int estimatedWidth = (int)Math.Round(original.Width * watermark.Ratio);
int estimatedHeight = (int)Math.Round(original.Height * watermark.Ratio);
//watermark.Image.Width > original.Width * watermark.Ratio ? (int)Math.Round(original.Width * watermark.Ratio) : watermark.Image.Width;
// watermark.Image.Height > original.Height * watermark.Ratio ? (int)Math.Round(original.Height * watermark.Ratio) : watermark.Image.Height;
if (watermark.Image.Width > estimatedWidth)
{
if (watermark.Image.Height > estimatedHeight)
{
if (estimatedHeight > estimatedWidth)
{
markWidth = estimatedWidth;
markHeight = watermark.Image.Height * estimatedWidth / watermark.Image.Width;
if (markHeight > estimatedHeight)
{
markWidth = estimatedHeight * estimatedHeight / markHeight;
markHeight = estimatedHeight;
}
}
else
{
markWidth = watermark.Image.Width * estimatedHeight / watermark.Image.Height;
markHeight = estimatedHeight;
if (markWidth > estimatedWidth)
{
markHeight = estimatedHeight * estimatedWidth / markWidth;
markWidth = estimatedWidth;
}
}
}
else
{
markWidth = estimatedWidth;
markHeight = watermark.Image.Height * estimatedWidth / watermark.Image.Width;
}
}
else
{
if (watermark.Image.Height > estimatedHeight)
{
markWidth = watermark.Image.Width * estimatedHeight / watermark.Image.Height;
markHeight = estimatedHeight;
}
else
{
markWidth = watermark.Image.Width;
markHeight = watermark.Image.Height;
}
}
int marginX = (int)Math.Round(watermark.MarginPercentage / 100 * original.Width);
int marginY = (int)Math.Round(watermark.MarginPercentage / 100 * original.Height);
switch (watermark.Alignment)
{
case ContentAlignment.TopLeft:
xpos = marginX;
ypos = marginY;
break;
case ContentAlignment.TopCenter:
xpos = (original.Width - markWidth) / 2;
ypos = marginY;
break;
case ContentAlignment.TopRight:
xpos = (original.Width - markWidth) - marginX;
ypos = marginY;
break;
case ContentAlignment.MiddleLeft:
xpos = marginX;
ypos = (original.Height - markHeight) / 2;
break;
case ContentAlignment.MiddleCenter:
xpos = (original.Width - markWidth) / 2;
ypos = (original.Height - markHeight) / 2;
break;
case ContentAlignment.MiddleRight:
xpos = (original.Width - markWidth) - marginX;
ypos = (original.Height - markHeight) / 2;
break;
case ContentAlignment.BottomLeft:
xpos = marginX;
ypos = (original.Height - markHeight) - marginY;
break;
case ContentAlignment.BottomCenter:
xpos = (original.Width - markWidth) / 2;
ypos = (original.Height - markHeight) - marginY;
break;
case ContentAlignment.BottomRight:
xpos = (original.Width - markWidth) - marginX;
ypos = (original.Height - markHeight) - marginY;
break;
default:
break;
}
Bitmap combined = new Bitmap(original);
// gdi+图片
Graphics g = Graphics.FromImage(combined);
// AntiAlias 指定消除锯齿的呈现。
// Default 指定不消除锯齿。
// HighQuality 指定高质量、低速度呈现。
// HighSpeed 指定高速度、低质量呈现。
// Invalid 指定一个无效模式。
// None 指定不消除锯齿。
g.SmoothingMode = SmoothingMode.AntiAlias;
//g.InterpolationMode = InterpolationMode.High;
//g.Clear(Color.White);
//g.DrawImage(combined, new Rectangle(0, 0, combined.Width, combined.Height));
g.DrawImage(watermark.Image, new Rectangle()
{
X = xpos, Y = ypos, Height = markHeight, Width = markWidth,
}, 0, 0, watermark.Image.Width, watermark.Image.Height, GraphicsUnit.Pixel);
imageAttributes.Dispose();
g.Dispose();
return(combined);
}
