如何调整大小并保存使用C#中的文件上传控件上传的图像 [英] How to resize and save an image which uploaded using file upload control in c#

问题描述

我已经使用asp.net mvc4和razor开发了一个Web应用程序.在我的应用程序中，有一个文件上传控件，用于上传图像并保存在一个临时位置.

在保存图像之前，应将其大小调整为特定大小，然后保存在给定的临时位置.

这是我在控制器类中使用的代码.

public class FileUploadController : Controller
{
    //
    // GET: /FileUpload/

    public ActionResult Index()
    {
        return View();
    }
    public ActionResult FileUpload()
    {
        return View();
    }

    [AcceptVerbs(HttpVerbs.Post)]
    public ActionResult FileUpload(HttpPostedFileBase uploadFile)
    {
        if (uploadFile.ContentLength > 0)
        {
            string relativePath = "~/img/" + Path.GetFileName(uploadFile.FileName);
            string physicalPath = Server.MapPath(relativePath);


            FileUploadModel.ResizeAndSave(relativePath, uploadFile.FileName, uploadFile.InputStream, uploadFile.ContentLength, true);

            return View((object)relativePath);
        }
        return View();
    }
}

这是模型类中使用的代码

public class FileUploadModel
{
    [Required]
    public HttpPostedFileWrapper ImageUploaded { get; set; }

    public static void ResizeAndSave(string savePath, string fileName, Stream imageBuffer, int maxSideSize, bool makeItSquare)
    {
        int newWidth;
        int newHeight;
        Image image = Image.FromStream(imageBuffer);
        int oldWidth = image.Width;
        int oldHeight = image.Height;
        Bitmap newImage;
        if (makeItSquare)
        {
            int smallerSide = oldWidth >= oldHeight ? oldHeight : oldWidth;
            double coeficient = maxSideSize / (double)smallerSide;
            newWidth = Convert.ToInt32(coeficient * oldWidth);
            newHeight = Convert.ToInt32(coeficient * oldHeight);
            Bitmap tempImage = new Bitmap(image, newWidth, newHeight);
            int cropX = (newWidth - maxSideSize) / 2;
            int cropY = (newHeight - maxSideSize) / 2;
            newImage = new Bitmap(maxSideSize, maxSideSize);
            Graphics tempGraphic = Graphics.FromImage(newImage);
            tempGraphic.SmoothingMode = SmoothingMode.AntiAlias;
            tempGraphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
            tempGraphic.PixelOffsetMode = PixelOffsetMode.HighQuality;
            tempGraphic.DrawImage(tempImage, new Rectangle(0, 0, maxSideSize, maxSideSize), cropX, cropY, maxSideSize, maxSideSize, GraphicsUnit.Pixel);
        }
        else
        {
            int maxSide = oldWidth >= oldHeight ? oldWidth : oldHeight;

            if (maxSide > maxSideSize)
            {
                double coeficient = maxSideSize / (double)maxSide;
                newWidth = Convert.ToInt32(coeficient * oldWidth);
                newHeight = Convert.ToInt32(coeficient * oldHeight);
            }
            else
            {
                newWidth = oldWidth;
                newHeight = oldHeight;
            }
            newImage = new Bitmap(image, newWidth, newHeight);
        }
        newImage.Save(savePath + fileName + ".jpg", ImageFormat.Jpeg);
        image.Dispose();
        newImage.Dispose();
    }
}

但是当我运行应用程序时，它会发生 ArgumentException .

在以下代码行中显示参数无效"

Bitmap tempImage = new Bitmap(image, newWidth, newHeight);

我如何在此处传递有效和适当的参数

public static void ResizeAndSave(string savePath, string fileName, Stream imageBuffer, int maxSideSize, bool makeItSquare)

解决方案

很难理解您的代码有什么问题.但是可能是您想使用替代方式.您需要添加对System.Web.Helpers命名空间的引用，然后尝试以下代码.

[HttpPost]
    public ActionResult Index(HttpPostedFileBase file)
    {
        WebImage img = new WebImage(file.InputStream);
        if (img.Width > 1000)
            img.Resize(1000, 1000);
        img.Save("path");
        return View();
    }

该类还支持裁剪，翻转，水印操作等.

i have developed a web application using asp.net mvc4 and razor. in my application there's a file upload control to upload an image and save in a temporary location.

before save image should re-sized to a specific size and then save in the temporary location given.

here is the code i have used in controller class.

public class FileUploadController : Controller
{
    //
    // GET: /FileUpload/

    public ActionResult Index()
    {
        return View();
    }
    public ActionResult FileUpload()
    {
        return View();
    }

    [AcceptVerbs(HttpVerbs.Post)]
    public ActionResult FileUpload(HttpPostedFileBase uploadFile)
    {
        if (uploadFile.ContentLength > 0)
        {
            string relativePath = "~/img/" + Path.GetFileName(uploadFile.FileName);
            string physicalPath = Server.MapPath(relativePath);


            FileUploadModel.ResizeAndSave(relativePath, uploadFile.FileName, uploadFile.InputStream, uploadFile.ContentLength, true);

            return View((object)relativePath);
        }
        return View();
    }
}

and here is the code used in model class

public class FileUploadModel
{
    [Required]
    public HttpPostedFileWrapper ImageUploaded { get; set; }

    public static void ResizeAndSave(string savePath, string fileName, Stream imageBuffer, int maxSideSize, bool makeItSquare)
    {
        int newWidth;
        int newHeight;
        Image image = Image.FromStream(imageBuffer);
        int oldWidth = image.Width;
        int oldHeight = image.Height;
        Bitmap newImage;
        if (makeItSquare)
        {
            int smallerSide = oldWidth >= oldHeight ? oldHeight : oldWidth;
            double coeficient = maxSideSize / (double)smallerSide;
            newWidth = Convert.ToInt32(coeficient * oldWidth);
            newHeight = Convert.ToInt32(coeficient * oldHeight);
            Bitmap tempImage = new Bitmap(image, newWidth, newHeight);
            int cropX = (newWidth - maxSideSize) / 2;
            int cropY = (newHeight - maxSideSize) / 2;
            newImage = new Bitmap(maxSideSize, maxSideSize);
            Graphics tempGraphic = Graphics.FromImage(newImage);
            tempGraphic.SmoothingMode = SmoothingMode.AntiAlias;
            tempGraphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
            tempGraphic.PixelOffsetMode = PixelOffsetMode.HighQuality;
            tempGraphic.DrawImage(tempImage, new Rectangle(0, 0, maxSideSize, maxSideSize), cropX, cropY, maxSideSize, maxSideSize, GraphicsUnit.Pixel);
        }
        else
        {
            int maxSide = oldWidth >= oldHeight ? oldWidth : oldHeight;

            if (maxSide > maxSideSize)
            {
                double coeficient = maxSideSize / (double)maxSide;
                newWidth = Convert.ToInt32(coeficient * oldWidth);
                newHeight = Convert.ToInt32(coeficient * oldHeight);
            }
            else
            {
                newWidth = oldWidth;
                newHeight = oldHeight;
            }
            newImage = new Bitmap(image, newWidth, newHeight);
        }
        newImage.Save(savePath + fileName + ".jpg", ImageFormat.Jpeg);
        image.Dispose();
        newImage.Dispose();
    }
}

but when i run the application it occurs an ArgumentException.

it says "Parameter is not valid" in following code line

Bitmap tempImage = new Bitmap(image, newWidth, newHeight);

how do i pass valid and appropriate parameters here

public static void ResizeAndSave(string savePath, string fileName, Stream imageBuffer, int maxSideSize, bool makeItSquare)

解决方案

Its very difficult to understand what is the problem with your code. But may be you want to use alternative way. You need to add the reference to System.Web.Helpers namespace and try the following code.

[HttpPost]
    public ActionResult Index(HttpPostedFileBase file)
    {
        WebImage img = new WebImage(file.InputStream);
        if (img.Width > 1000)
            img.Resize(1000, 1000);
        img.Save("path");
        return View();
    }

Also this class supports the crop, flip, watermark operation etc.

这篇关于如何调整大小并保存使用C#中的文件上传控件上传的图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！