/// <summary>
/// 按指定大小裁切图片，如果指定大小超过原始图片，将按原始图片尺寸输出
/// </summary>
/// <param name="sourceImagePath">原始图片地址</param>
/// <param name="newImagePath">新图片地址</param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="imageFormat"></param>
/// <param name="position">裁切开始位置</param>
/// <returns></returns>
public static bool CutImage(string sourceImagePath, string newImagePath, int width, int height, ImageFormat imageFormat, CutImagePosition position)
{
using (FileStream fs = new FileStream(sourceImagePath, FileMode.Open))
{
return(CutImage(fs, newImagePath, width, height, imageFormat, position));
}
}
/// <summary>
/// 按指定大小裁切图片，如果指定大小超过原始图片，将按原始图片尺寸输出
/// </summary>
/// <param name="sourceStream">原始图片流</param>
/// <param name="newImagePath">新图片地址</param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="imageFormat"></param>
/// <param name="position">裁切开始位置</param>
/// <returns></returns>
public static bool CutImage(Stream sourceStream, string newImagePath, int width, int height, ImageFormat imageFormat, CutImagePosition position)
{
bool result = false;
try
{
string newImageDirPath = Path.GetDirectoryName(newImagePath);
if (!Directory.Exists(newImageDirPath))
{
Directory.CreateDirectory(newImageDirPath);
}
string newImageTempPath = Path.Combine(newImageDirPath, Path.GetFileNameWithoutExtension(newImagePath) + "_temp_" + DateTime.Now.ToString("yyyyMMddHHmmss") + "_" + Path.GetExtension(newImagePath));
int orgWidth = 0, orgHeight = 0;
using (Image img = Image.FromStream(sourceStream))
{
orgWidth = img.Width;
orgHeight = img.Height;
if (width >= orgWidth && height >= orgHeight)
{
using (FileStream fs = new FileStream(newImagePath, FileMode.OpenOrCreate))
{
byte[] sourceBuffer = new byte[sourceStream.Length];
fs.Write(sourceBuffer, 0, sourceBuffer.Length);
}
return(true);
}
else
{
if (width > orgWidth)
{
width = orgWidth;
}
if (height > orgHeight)
{
height = orgHeight;
}
}
}
//获取系统编码类型数组,包含了jpeg,bmp,png,gif,tiff
ImageCodecInfo[] icis = ImageCodecInfo.GetImageEncoders();
ImageCodecInfo ici = null;
foreach (ImageCodecInfo i in icis)
{
if (i.FormatID == imageFormat.Guid)
{
ici = i;
break;
}
}
EncoderParameters ep = new EncoderParameters(1);
ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100);
using (Bitmap bitmap = new Bitmap(width, height))
{
bitmap.Save(newImageTempPath, ici, ep);
}
int x, y;
switch (position)
{
case CutImagePosition.TopLeft:
default:
x = 0;
y = 0;
break;
case CutImagePosition.TopCenter:
x = Convert.ToInt32((orgWidth - width) / 2);
y = 0;
break;
case CutImagePosition.TopRight:
x = (orgWidth - width);
y = 0;
break;
case CutImagePosition.MiddleRight:
x = (orgWidth - width);
y = Convert.ToInt32((orgHeight - height) / 2);
break;
case CutImagePosition.BottomRight:
x = (orgWidth - width);
y = (orgHeight - height);
break;
case CutImagePosition.BottomCenter:
x = Convert.ToInt32((orgWidth - width) / 2);
y = (orgHeight - height);
break;
case CutImagePosition.BottomLeft:
x = 0;
y = (orgHeight - height);
break;
case CutImagePosition.MiddleLeft:
x = 0;
y = Convert.ToInt32((orgHeight - height) / 2);
break;
case CutImagePosition.Top:
x = 0;
y = 0;
break;
case CutImagePosition.Left:
x = 0;
y = 0;
break;
case CutImagePosition.Right:
x = (orgWidth - width);
y = 0;
break;
case CutImagePosition.Bottom:
x = 0;
y = (orgHeight - height);
break;
}
Graphics g = null;
using (Image tempImg = Image.FromFile(newImageTempPath))
{
using (Image img = Image.FromStream(sourceStream))
{
g = Graphics.FromImage(tempImg);
g.DrawImage(img, new Rectangle(0, 0, width, height), new Rectangle(x, y, width, height), GraphicsUnit.Pixel);
g.Save();
}
tempImg.Save(newImagePath);
}
g.Dispose();
File.Delete(newImageTempPath);
result = true;
}
catch (Exception ex)
{
LogHelper.WriteLog_LocalTxt(ex.ToString());
result = false;
}
return(result);
}
/// <summary>
/// 按百分比裁切图片
/// </summary>
/// <param name="sourceStream">原始图片流</param>
/// <param name="newImagePath">新图片地址</param>
/// <param name="percentage">百分比</param>
/// <param name="imageFormat"></param>
/// <param name="position">裁切开始位置</param>
/// <returns></returns>
public static bool CutImage(Stream sourceStream, string newImagePath, double percentage, ImageFormat imageFormat, CutImagePosition position)
{
int orgWidth = 0, orgHeight = 0;
int newWidth = 0, newHeight = 0;
using (Image img = Image.FromStream(sourceStream))
{
orgWidth = img.Width;
orgHeight = img.Height;
switch (position)
{
case CutImagePosition.Top:
case CutImagePosition.Bottom:
newWidth = orgWidth;
newHeight = Convert.ToInt32(orgHeight * percentage);
break;
case CutImagePosition.Left:
case CutImagePosition.Right:
newWidth = Convert.ToInt32(orgWidth * percentage);
newHeight = orgHeight;
break;
default:
newWidth = Convert.ToInt32(orgWidth * percentage);
newHeight = Convert.ToInt32(orgHeight * percentage);
break;
}
}
return(CutImage(sourceStream, newImagePath, newWidth, newHeight, imageFormat, position));
}
