/// <summary>
/// 获取缩略图尺寸
/// </summary>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="mode"></param>
/// <param name="src"></param>
/// <returns></returns>
public static ThumbSize getTargetSize(int width, int height, SaveThumbnailMode mode, Image src)
{
ThumbSize t = new ThumbSize();
t.Src = new Size(src.Width, src.Height);
t.Point = new Point(0, 0);
if (mode == SaveThumbnailMode.ByWidth)
{
int newHeight = src.Height * width / src.Width;
t.New = new Size(width, newHeight);
return(t);
}
else if (mode == SaveThumbnailMode.ByHeight)
{
int newWidth = src.Width * height / src.Height;
t.New = new Size(newWidth, height);
return(t);
}
else if (mode == SaveThumbnailMode.ByWidthHeight)
{
t.New = new Size(width, height);
return(t);
}
else if (mode == SaveThumbnailMode.Cut)
{
return(getCutSize(width, height, mode, src));
}
return(getAutoSize(width, height, mode, src));
}
/// <summary>
/// 保存缩略图到磁盘(可指定宽高，可指定缩放模式)
/// </summary>
/// <param name="srcPath"></param>
/// <param name="destPath"></param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="mode"></param>
public static void SaveThumbnail(String srcPath, String destPath, int width, int height, SaveThumbnailMode mode)
{
try {
using (Image srcImg = Image.FromFile(srcPath)) {
ThumbSize t = getTargetSize(width, height, mode, srcImg);
using (Bitmap newImg = new Bitmap(t.New.Width, t.New.Height)) {
using (Graphics g = Graphics.FromImage(newImg)) {
g.InterpolationMode = InterpolationMode.High;
g.SmoothingMode = SmoothingMode.HighQuality;
g.Clear(Color.White);
g.DrawImage(srcImg, t.getNewRect(), t.getRect(), GraphicsUnit.Pixel);
try {
newImg.Save(destPath, ImageFormat.Jpeg);
}
catch (Exception e) {
throw e;
}
}
}
}
}
catch (OutOfMemoryException ex) {
logger.Error("file format error: " + srcPath);
}
}
private static ThumbSize getCutSize(int width, int height, SaveThumbnailMode mode, Image src)
{
ThumbSize t = new ThumbSize();
if ((double)src.Width / (double)src.Height > (double)width / (double)height)
{
int newWidth = src.Height * width / height;
t.Src = new Size(newWidth, src.Height);
t.New = new Size(width, height);
t.Point = new Point((src.Width - newWidth) / 2, 0);
}
else
{
int newHeight = src.Width * height / width;
t.Src = new Size(src.Width, newHeight);
t.New = new Size(width, height);
t.Point = new Point(0, (src.Height - newHeight) / 2);
}
return(t);
}
private static ThumbSize getAutoSize(int width, int height, SaveThumbnailMode mode, Image src)
{
ThumbSize t = new ThumbSize();
t.Src = new Size(src.Width, src.Height);
t.Point = new Point(0, 0);
int newWidth = width;
int newHeight = height;
if ((double)src.Width / (double)src.Height > (double)width / (double)height)
{
newHeight = src.Height * width / src.Width;
}
else
{
newWidth = src.Width * height / src.Height;
}
t.New = new Size(newWidth, newHeight);
return(t);
}
private static ThumbSize getCutSize( int width, int height, SaveThumbnailMode mode, Image src )
{
ThumbSize t = new ThumbSize();
if ((double)src.Width / (double)src.Height > (double)width / (double)height) {
int newWidth = src.Height * width / height;
t.Src = new Size( newWidth, src.Height );
t.New = new Size( width, height );
t.Point = new Point( (src.Width - newWidth) / 2, 0 );
}
else {
int newHeight = src.Width * height / width;
t.Src = new Size( src.Width, newHeight );
t.New = new Size( width, height );
t.Point = new Point( 0, (src.Height - newHeight) / 2 );
}
return t;
}
private static ThumbSize getAutoSize( int width, int height, SaveThumbnailMode mode, Image src )
{
ThumbSize t = new ThumbSize();
t.Src = new Size( src.Width, src.Height );
t.Point = new Point( 0, 0 );
int newWidth = width;
int newHeight = height;
if ((double)src.Width / (double)src.Height > (double)width / (double)height)
newHeight = src.Height * width / src.Width;
else
newWidth = src.Width * height / src.Height;
t.New = new Size( newWidth, newHeight );
return t;
}
/// <summary>
/// 获取缩略图尺寸
/// </summary>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="mode"></param>
/// <param name="src"></param>
/// <returns></returns>
public static ThumbSize getTargetSize( int width, int height, SaveThumbnailMode mode, Image src )
{
ThumbSize t = new ThumbSize();
t.Src = new Size( src.Width, src.Height );
t.Point = new Point( 0, 0 );
if (mode == SaveThumbnailMode.ByWidth) {
int newHeight = src.Height * width / src.Width;
t.New = new Size( width, newHeight );
return t;
}
else if (mode == SaveThumbnailMode.ByHeight) {
int newWidth = src.Width * height / src.Height;
t.New = new Size( newWidth, height );
return t;
}
else if (mode == SaveThumbnailMode.ByWidthHeight) {
t.New = new Size( width, height );
return t;
}
else if (mode == SaveThumbnailMode.Cut) {
return getCutSize( width, height, mode, src );
}
return getAutoSize( width, height, mode, src );
}
