/// <summary>
/// 图片水印
/// </summary>
/// <param name="destBitmap"></param>
/// <param name="watermarkBitmap"></param>
/// <param name="currentSettings"></param>
private void PlaceImageWatermark(Bitmap destBitmap, Bitmap watermarkBitmap, WatermarkSettings currentSettings)
{
currentSettings = currentSettings ?? new WatermarkSettings();
using (Graphics g = Graphics.FromImage(destBitmap))
{
Bitmap rotateImage = null;
if (currentSettings.ImageRotatedDegree > 0)
{
rotateImage = GetRotateImage(watermarkBitmap, currentSettings.ImageRotatedDegree);
}
if (rotateImage != null)
{
watermarkBitmap = rotateImage;
}
double watermarkSizeInPercent = (double)currentSettings.PictureSettings.Size / 100;
Size boundingBoxSize = new Size((int)(destBitmap.Width * watermarkSizeInPercent),
(int)(destBitmap.Height * watermarkSizeInPercent));
Size calculatedWatermarkSize = ScaleRectangleToFitBounds(boundingBoxSize, watermarkBitmap.Size);
if (calculatedWatermarkSize.Width == 0 || calculatedWatermarkSize.Height == 0)
{
return;
}
Bitmap scaledWatermarkBitmap =
new Bitmap(calculatedWatermarkSize.Width, calculatedWatermarkSize.Height);
using (Graphics watermarkGraphics = Graphics.FromImage(scaledWatermarkBitmap))
{
ColorMatrix opacityMatrix = new ColorMatrix
{
Matrix33 = (float)currentSettings.PictureSettings.Opacity
};
ImageAttributes attrs = new ImageAttributes();
attrs.SetColorMatrix(opacityMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
watermarkGraphics.DrawImage(watermarkBitmap,
new Rectangle(0, 0, scaledWatermarkBitmap.Width, scaledWatermarkBitmap.Height),
0, 0, watermarkBitmap.Width, watermarkBitmap.Height,
GraphicsUnit.Pixel, attrs);
attrs.Dispose();
}
foreach (var position in currentSettings.PictureSettings.PositionList)
{
Point watermarkPosition = CalculateWatermarkPosition(position,
destBitmap.Size, calculatedWatermarkSize);
g.DrawImage(scaledWatermarkBitmap,
new Rectangle(watermarkPosition, calculatedWatermarkSize),
0, 0, calculatedWatermarkSize.Width, calculatedWatermarkSize.Height, GraphicsUnit.Pixel);
}
scaledWatermarkBitmap.Dispose();
}
}
/// <summary>
/// 文字水印
/// </summary>
/// <param name="sourceBitmap"></param>
/// <param name="currentSettings"></param>
private void PlaceTextWatermark(Bitmap sourceBitmap, WatermarkSettings currentSettings)
{
using (Graphics g = Graphics.FromImage(sourceBitmap))
{
g.SmoothingMode = SmoothingMode.HighQuality;
g.CompositingQuality = CompositingQuality.HighQuality;
g.InterpolationMode = InterpolationMode.Default;
g.SmoothingMode = SmoothingMode.AntiAlias;
g.TextRenderingHint = TextRenderingHint.AntiAlias;
string text = currentSettings.WatermarkText;
int textAngle = currentSettings.TextRotatedDegree;
double sizeFactor = (double)currentSettings.TextSettings.Size / 100;
Size maxTextSize = new Size(
(int)(sourceBitmap.Width * sizeFactor),
(int)(sourceBitmap.Height * sizeFactor));
int fontSize = ComputeMaxFontSize(text, textAngle, currentSettings.WatermarkFont, maxTextSize, g);
Font font = new Font(currentSettings.WatermarkFont, (float)fontSize, FontStyle.Bold);
SizeF originalTextSize = g.MeasureString(text, font);
SizeF rotatedTextSize = CalculateRotatedRectSize(originalTextSize, textAngle);
Bitmap textBitmap = new Bitmap((int)rotatedTextSize.Width, (int)rotatedTextSize.Height,
PixelFormat.Format32bppArgb);
using (Graphics textG = Graphics.FromImage(textBitmap))
{
Color color = Color.FromArgb((int)(currentSettings.TextSettings.Opacity * 255), currentSettings.TextColor);
SolidBrush brush = new SolidBrush(color);
textG.TranslateTransform(rotatedTextSize.Width / 2, rotatedTextSize.Height / 2);
textG.RotateTransform((float)textAngle);
textG.DrawString(text, font, brush, -originalTextSize.Width / 2,
-originalTextSize.Height / 2);
textG.ResetTransform();
brush.Dispose();
}
foreach (var position in currentSettings.TextSettings.PositionList)
{
Point textPosition = CalculateWatermarkPosition(position,
sourceBitmap.Size, rotatedTextSize.ToSize());
g.DrawImage(textBitmap, textPosition);
}
textBitmap.Dispose();
font.Dispose();
}
}
public Image MakeImageWatermark(Image sourceImage, WatermarkSettings currentSettings)
{
if ((sourceImage.Height > currentSettings.MinimumImageHeightForWatermark) ||
(sourceImage.Width > currentSettings.MinimumImageWidthForWatermark))
{
Bitmap destBitmap = CreateBitmap(sourceImage);
if (currentSettings.WatermarkTextEnable && !String.IsNullOrEmpty(currentSettings.WatermarkText))
{
PlaceTextWatermark(destBitmap, currentSettings);
}
if (currentSettings.WatermarkPictureEnable && watermarkBitmap.Value != null)
{
PlaceImageWatermark(destBitmap, watermarkBitmap.Value, currentSettings);
}
sourceImage?.Dispose();
return(destBitmap);
}
return(sourceImage);
}
