Here is my code:
protected void SaveMyImage_Click(object sender, EventArgs e)
{
string imageUrl = Hidden1.Value;
string saveLocation = Server.MapPath("~/PictureUploads/whatever2.png") ;
HttpWebRequest imageRequest = (HttpWebRequest)WebRequest.Create(imageUrl);
WebResponse imageResponse = imageRequest.GetResponse();
Stream responseStream = imageResponse.GetResponseStream();
using (BinaryReader br = new BinaryReader(responseStream))
{
imageBytes = br.ReadBytes(500000);
br.Close();
}
responseStream.Close();
imageResponse.Close();
FileStream fs = new FileStream(saveLocation, FileMode.Create);
BinaryWriter bw = new BinaryWriter(fs);
try
{
bw.Write(imageBytes);
}
finally
{
fs.Close();
bw.Close();
}
}
}
The top imageUrl declartion is taking in a Base64 image string, and I want to convert it into an image. I think my set of code only works for images like "www.mysite.com/test.jpg" not for a Base64 string. Anybody have some suggestions? Thanks!
Here is an example, you can modify the method to accept a string parameter. Then just save the image object with image.Save(...).
public Image LoadImage()
{
//data:image/gif;base64,
//this image is a single pixel (black)
byte[] bytes = Convert.FromBase64String("R0lGODlhAQABAIAAAAAAAAAAACH5BAAAAAAALAAAAAABAAEAAAICTAEAOw==");
Image image;
using (MemoryStream ms = new MemoryStream(bytes))
{
image = Image.FromStream(ms);
}
return image;
}
It is possible to get an exception A generic error occurred in GDI+. when the bytes represent a bitmap. If this is happening save the image before disposing the memory stream (while still inside the using statement).
You can save Base64 directly into file:
string filePath = "MyImage.jpg";
File.WriteAllBytes(filePath, Convert.FromBase64String(base64imageString));
Here is what I ended up going with.
private void SaveByteArrayAsImage(string fullOutputPath, string base64String)
{
byte[] bytes = Convert.FromBase64String(base64String);
Image image;
using (MemoryStream ms = new MemoryStream(bytes))
{
image = Image.FromStream(ms);
}
image.Save(fullOutputPath, System.Drawing.Imaging.ImageFormat.Png);
}
I would suggest via Bitmap:
public void SaveImage(string base64)
{
using (MemoryStream ms = new MemoryStream(Convert.FromBase64String(base64)))
{
using (Bitmap bm2 = new Bitmap(ms))
{
bm2.Save("SavingPath" + "ImageName.jpg");
}
}
}
Here is working code for converting an image from a base64 string to an Image object and storing it in a folder with unique file name:
public void SaveImage()
{
string strm = "R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7";
//this is a simple white background image
var myfilename= string.Format(#"{0}", Guid.NewGuid());
//Generate unique filename
string filepath= "~/UserImages/" + myfilename+ ".jpeg";
var bytess = Convert.FromBase64String(strm);
using (var imageFile = new FileStream(filepath, FileMode.Create))
{
imageFile.Write(bytess, 0, bytess.Length);
imageFile.Flush();
}
}
In my case it works only with two line of code. Test the below C# code:
String dirPath = "C:\myfolder\";
String imgName = "my_mage_name.bmp";
byte[] imgByteArray = Convert.FromBase64String("your_base64_string");
File.WriteAllBytes(dirPath + imgName, imgByteArray);
That's it. Kindly up vote if you really find this solution works for you. Thanks in advance.
In a similar scenario what worked for me was the following:
byte[] bytes = Convert.FromBase64String(Base64String);
ImageTagId.ImageUrl = "data:image/jpeg;base64," + Convert.ToBase64String(bytes);
ImageTagId is the ID of the ASP image tag.
If you have a string of binary data which is Base64 encoded, you should be able to do the following:
byte[] encodedDataAsBytes = System.Convert.FromBase64String(encodedData);
You should be able to write the resulting array to a file.
public bool SaveBase64(string Dir, string FileName, string FileType, string Base64ImageString)
{
try
{
string folder = System.Web.HttpContext.Current.Server.MapPath("~/") + Dir;
if (!Directory.Exists(folder))
{
Directory.CreateDirectory(folder);
}
string filePath = folder + "/" + FileName + "." + FileType;
File.WriteAllBytes(filePath, Convert.FromBase64String(Base64ImageString));
return true;
}
catch
{
return false;
}
}
Using MemoryStream is not a good idea and violates a specification in MSDN for Image.FromStream(), where it says
You must keep the stream open for the lifetime of the Image.
A better solution is using ImageConverter, e.g:
public Image ConvertBase64ToImage(string base64)
=> (Bitmap)new ImageConverter().ConvertFrom(Convert.FromBase64String(base64));
In NetCore 6.0, you can use HttpClient and the async methods in the new File class.
The implementation is very simple:
static async Task DownloadFile(string imageUrl, string pathToSave)
{
var content = await GetUrlContent(url);
if (content != null)
{
await File.WriteAllBytesAsync(pathToSave, content);
}
}
static async Task<byte[]?> GetUrlContent(string url)
{
using (var client = new HttpClient())
using (var result = await client.GetAsync(url))
return result.IsSuccessStatusCode ? await result.Content.ReadAsByteArrayAsync():null;
}
Usage:
await DownloadFile("https://example.com/image.jpg", #"c:\temp\image.jpg");
Related
So I am trying to convert an image base64 that will be uploaded to SQL Server.
Current code is:
private async Task OnInputFileChange(InputFileChangeEventArgs args)
{
var maxFiles = 1;
var maxSize = 512000000;
var format = "image/jpg";
test = "Something";
test1 = args.FileCount.ToString();
foreach (var file in args.GetMultipleFiles(maxFiles))
{
var image = await file.RequestImageFileAsync(format, 500, 500);
test = image.Size.ToString();
buffer = new byte[image.Size];
await image.OpenReadStream(maxAllowedSize: maxSize).ReadAsync(buffer);
test1 = buffer.ToString();
var imageDataUrl = $"data:{format};base64,{Convert.ToBase64String(buffer)}";
imageDataUrls.Add(imageDataUrl);
imageString = imageDataUrl;
}
}
It begins fine, however only the top portion of image is actually converted and in the string is followed by thousands of repeating "A". Reconstructing the image just shows the top portion of the image. What am I doing wrong?
Currently I had not uploaded and redownloaded the string, it is all local until I can figure out what is wrong. I am using the imageString for the image source. I am using .net 6.0.
Try this. Works for me. Files since 1 MB.
public static byte[] GetBytes(Stream stream)
{
var bytes = new byte[stream.Length];
stream.Seek(0, SeekOrigin.Begin);
stream.ReadAsync(bytes, 0, bytes.Length);
stream.Dispose();
return bytes;
}
private async Task OnInputFileChange(InputFileChangeEventArgs args)
{
string base64String = "";
try
{
var files = args.GetMultipleFiles();
foreach (var file in files)
{
await using MemoryStream fs = new MemoryStream();
await file.OpenReadStream(maxAllowedSize: 1048576).CopyToAsync(fs);
byte[] somBytes = GetBytes(fs);
base64String = Convert.ToBase64String(somBytes, 0, somBytes.Length);
System.Diagnostics.Debug.Print("Imatge 64: " + base64String + Environment.NewLine);
}
}
catch (Exception e)
{
System.Diagnostics.Debug.Print("ERROR: " + e.Message + Environment.NewLine);
}
}
Hi so I'm trying to save an image selected by the user to file so that i can later upload it to my mySQL database.
So I have this code:
var result = await MediaPicker.PickPhotoAsync(new MediaPickerOptions
{
Title = "Please pick a selfie"
});
var stream = await result.OpenReadAsync();
resultImage.Source = ImageSource.FromStream(() => stream);
string path = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
string filename = Path.Combine(path, "myfile");
using (var streamWriter = new StreamWriter(filename, true))
{
streamWriter.WriteLine(GetImageBytes(stream).ToString());
}
using (var streamReader = new StreamReader(filename))
{
string content = streamReader.ReadToEnd();
System.Diagnostics.Debug.WriteLine(content);
}
Here's the GetImageBytes(..) function:
private byte[] GetImageBytes(Stream stream)
{
byte[] ImageBytes;
using (var memoryStream = new System.IO.MemoryStream())
{
stream.CopyTo(memoryStream);
ImageBytes = memoryStream.ToArray();
}
return ImageBytes;
}
The code kind of works, it creates a file but doesn't save the image. Instead it saves "System.Bytes[]". It saves the name of the object, not the contents of the object.
myfile
enter image description here
Any help would be really appreciated. Thanks!
StreamWriter is for writing formatted strings, not binary data. Try this instead
File.WriteAllBytes(filename,GetImageBytes(stream));
Encode the byte array as a base64 string, then store that in the file:
private string GetImageBytesAsBase64String(Stream stream)
{
var imageBytes;
using (var memoryStream = new System.IO.MemoryStream())
{
stream.CopyTo(memoryStream);
imageBytes = memoryStream.ToArray();
}
return Convert.ToBase64String(imageBytes);
}
If you later need to retrieve the image bytes from the file, you can use the corresponding Convert.FromBase64String(imageBytesAsBase64String) method.
How do you convert an image from a path on the user's computer to a base64 string in C#?
For example, I have the path to the image (in the format C:/image/1.gif) and would like to have a data URI like data:image/gif;base64,/9j/4AAQSkZJRgABAgEAYABgAAD.. representing the 1.gif image returned.
Try this
using (Image image = Image.FromFile(Path))
{
using (MemoryStream m = new MemoryStream())
{
image.Save(m, image.RawFormat);
byte[] imageBytes = m.ToArray();
// Convert byte[] to Base64 String
string base64String = Convert.ToBase64String(imageBytes);
return base64String;
}
}
Get the byte array (byte[]) representation of the image, then use Convert.ToBase64String(), st. like this:
byte[] imageArray = System.IO.File.ReadAllBytes(#"image file path");
string base64ImageRepresentation = Convert.ToBase64String(imageArray);
To convert a base64 image back to a System.Drawing.Image:
var img = Image.FromStream(new MemoryStream(Convert.FromBase64String(base64String)));
Since most of us like oneliners:
Convert.ToBase64String(File.ReadAllBytes(imageFilepath));
If you need it as Base64 byte array:
Encoding.ASCII.GetBytes(Convert.ToBase64String(File.ReadAllBytes(imageFilepath)));
This is the class I wrote for this purpose:
public class Base64Image
{
public static Base64Image Parse(string base64Content)
{
if (string.IsNullOrEmpty(base64Content))
{
throw new ArgumentNullException(nameof(base64Content));
}
int indexOfSemiColon = base64Content.IndexOf(";", StringComparison.OrdinalIgnoreCase);
string dataLabel = base64Content.Substring(0, indexOfSemiColon);
string contentType = dataLabel.Split(':').Last();
var startIndex = base64Content.IndexOf("base64,", StringComparison.OrdinalIgnoreCase) + 7;
var fileContents = base64Content.Substring(startIndex);
var bytes = Convert.FromBase64String(fileContents);
return new Base64Image
{
ContentType = contentType,
FileContents = bytes
};
}
public string ContentType { get; set; }
public byte[] FileContents { get; set; }
public override string ToString()
{
return $"data:{ContentType};base64,{Convert.ToBase64String(FileContents)}";
}
}
var base64Img = new Base64Image {
FileContents = File.ReadAllBytes("Path to image"),
ContentType="image/png"
};
string base64EncodedImg = base64Img.ToString();
You can easily pass the path of the image to retrieve the base64 string
public static string ImageToBase64(string _imagePath)
{
string _base64String = null;
using (System.Drawing.Image _image = System.Drawing.Image.FromFile(_imagePath))
{
using (MemoryStream _mStream = new MemoryStream())
{
_image.Save(_mStream, _image.RawFormat);
byte[] _imageBytes = _mStream.ToArray();
_base64String = Convert.ToBase64String(_imageBytes);
return "data:image/jpg;base64," + _base64String;
}
}
}
Hope this will help.
You can use Server.Map path to give relative path and then you can either create image using base64 conversion or you can just add base64 string to image src.
byte[] imageArray = System.IO.File.ReadAllBytes(Server.MapPath("~/Images/Upload_Image.png"));
string base64ImageRepresentation = Convert.ToBase64String(imageArray);
This code works well with me on DotNet Core 6
using (Image image = Image.FromFile(path))
{
using (MemoryStream m = new MemoryStream())
{
image.Save(m, ImageFormat.Jpeg);
byte[] imageBytes = m.ToArray();
// Convert byte[] to Base64 String
string base64String = Convert.ToBase64String(imageBytes);
// In my case I didn't find the part "data:image/png;base64,", so I added.
return $"data:image/png;base64,{base64String}";
}
}
That way it's simpler, where you pass the image and then pass the format.
private static string ImageToBase64(Image image)
{
var imageStream = new MemoryStream();
try
{
image.Save(imageStream, System.Drawing.Imaging.ImageFormat.Bmp);
imageStream.Position = 0;
var imageBytes = imageStream.ToArray();
var ImageBase64 = Convert.ToBase64String(imageBytes);
return ImageBase64;
}
catch (Exception ex)
{
return "Error converting image to base64!";
}
finally
{
imageStream.Dispose;
}
}
Based on top voted answer, updated for C# 8. Following can be used out of the box. Added explicit System.Drawing before Image as one might be using that class from other namespace defaultly.
public static string ImagePathToBase64(string path)
{
using System.Drawing.Image image = System.Drawing.Image.FromFile(path);
using MemoryStream m = new MemoryStream();
image.Save(m, image.RawFormat);
byte[] imageBytes = m.ToArray();
tring base64String = Convert.ToBase64String(imageBytes);
return base64String;
}
The following piece of code works for me:
string image_path="physical path of your image";
byte[] byes_array = System.IO.File.ReadAllBytes(Server.MapPath(image_path));
string base64String = Convert.ToBase64String(byes_array);
The reverse of this for the googlers arriving here (there is no SO quesion/answer to that)
public static byte[] BytesFromBase64ImageString(string imageData)
{
var trunc = imageData.Split(',')[1];
var padded = trunc.PadRight(trunc.Length + (4 - trunc.Length % 4) % 4, '=');
return Convert.FromBase64String(padded);
}
Something like that
Function imgTo64(ByVal thePath As String) As String
Dim img As System.Drawing.Image = System.Drawing.Image.FromFile(thePath)
Dim m As IO.MemoryStream = New IO.MemoryStream()
img.Save(m, img.RawFormat)
Dim imageBytes As Byte() = m.ToArray
img.Dispose()
Dim str64 = Convert.ToBase64String(imageBytes)
Return str64
End Function
How do you convert an image from a path on the user's computer to a base64 string in C#?
For example, I have the path to the image (in the format C:/image/1.gif) and would like to have a data URI like data:image/gif;base64,/9j/4AAQSkZJRgABAgEAYABgAAD.. representing the 1.gif image returned.
Try this
using (Image image = Image.FromFile(Path))
{
using (MemoryStream m = new MemoryStream())
{
image.Save(m, image.RawFormat);
byte[] imageBytes = m.ToArray();
// Convert byte[] to Base64 String
string base64String = Convert.ToBase64String(imageBytes);
return base64String;
}
}
Get the byte array (byte[]) representation of the image, then use Convert.ToBase64String(), st. like this:
byte[] imageArray = System.IO.File.ReadAllBytes(#"image file path");
string base64ImageRepresentation = Convert.ToBase64String(imageArray);
To convert a base64 image back to a System.Drawing.Image:
var img = Image.FromStream(new MemoryStream(Convert.FromBase64String(base64String)));
Since most of us like oneliners:
Convert.ToBase64String(File.ReadAllBytes(imageFilepath));
If you need it as Base64 byte array:
Encoding.ASCII.GetBytes(Convert.ToBase64String(File.ReadAllBytes(imageFilepath)));
This is the class I wrote for this purpose:
public class Base64Image
{
public static Base64Image Parse(string base64Content)
{
if (string.IsNullOrEmpty(base64Content))
{
throw new ArgumentNullException(nameof(base64Content));
}
int indexOfSemiColon = base64Content.IndexOf(";", StringComparison.OrdinalIgnoreCase);
string dataLabel = base64Content.Substring(0, indexOfSemiColon);
string contentType = dataLabel.Split(':').Last();
var startIndex = base64Content.IndexOf("base64,", StringComparison.OrdinalIgnoreCase) + 7;
var fileContents = base64Content.Substring(startIndex);
var bytes = Convert.FromBase64String(fileContents);
return new Base64Image
{
ContentType = contentType,
FileContents = bytes
};
}
public string ContentType { get; set; }
public byte[] FileContents { get; set; }
public override string ToString()
{
return $"data:{ContentType};base64,{Convert.ToBase64String(FileContents)}";
}
}
var base64Img = new Base64Image {
FileContents = File.ReadAllBytes("Path to image"),
ContentType="image/png"
};
string base64EncodedImg = base64Img.ToString();
You can easily pass the path of the image to retrieve the base64 string
public static string ImageToBase64(string _imagePath)
{
string _base64String = null;
using (System.Drawing.Image _image = System.Drawing.Image.FromFile(_imagePath))
{
using (MemoryStream _mStream = new MemoryStream())
{
_image.Save(_mStream, _image.RawFormat);
byte[] _imageBytes = _mStream.ToArray();
_base64String = Convert.ToBase64String(_imageBytes);
return "data:image/jpg;base64," + _base64String;
}
}
}
Hope this will help.
You can use Server.Map path to give relative path and then you can either create image using base64 conversion or you can just add base64 string to image src.
byte[] imageArray = System.IO.File.ReadAllBytes(Server.MapPath("~/Images/Upload_Image.png"));
string base64ImageRepresentation = Convert.ToBase64String(imageArray);
This code works well with me on DotNet Core 6
using (Image image = Image.FromFile(path))
{
using (MemoryStream m = new MemoryStream())
{
image.Save(m, ImageFormat.Jpeg);
byte[] imageBytes = m.ToArray();
// Convert byte[] to Base64 String
string base64String = Convert.ToBase64String(imageBytes);
// In my case I didn't find the part "data:image/png;base64,", so I added.
return $"data:image/png;base64,{base64String}";
}
}
That way it's simpler, where you pass the image and then pass the format.
private static string ImageToBase64(Image image)
{
var imageStream = new MemoryStream();
try
{
image.Save(imageStream, System.Drawing.Imaging.ImageFormat.Bmp);
imageStream.Position = 0;
var imageBytes = imageStream.ToArray();
var ImageBase64 = Convert.ToBase64String(imageBytes);
return ImageBase64;
}
catch (Exception ex)
{
return "Error converting image to base64!";
}
finally
{
imageStream.Dispose;
}
}
Based on top voted answer, updated for C# 8. Following can be used out of the box. Added explicit System.Drawing before Image as one might be using that class from other namespace defaultly.
public static string ImagePathToBase64(string path)
{
using System.Drawing.Image image = System.Drawing.Image.FromFile(path);
using MemoryStream m = new MemoryStream();
image.Save(m, image.RawFormat);
byte[] imageBytes = m.ToArray();
tring base64String = Convert.ToBase64String(imageBytes);
return base64String;
}
The following piece of code works for me:
string image_path="physical path of your image";
byte[] byes_array = System.IO.File.ReadAllBytes(Server.MapPath(image_path));
string base64String = Convert.ToBase64String(byes_array);
The reverse of this for the googlers arriving here (there is no SO quesion/answer to that)
public static byte[] BytesFromBase64ImageString(string imageData)
{
var trunc = imageData.Split(',')[1];
var padded = trunc.PadRight(trunc.Length + (4 - trunc.Length % 4) % 4, '=');
return Convert.FromBase64String(padded);
}
Something like that
Function imgTo64(ByVal thePath As String) As String
Dim img As System.Drawing.Image = System.Drawing.Image.FromFile(thePath)
Dim m As IO.MemoryStream = New IO.MemoryStream()
img.Save(m, img.RawFormat)
Dim imageBytes As Byte() = m.ToArray
img.Dispose()
Dim str64 = Convert.ToBase64String(imageBytes)
Return str64
End Function
I'm using Magick.NET to convert a PDF to a PNG and stream it back to the page via ajax.
Everything works until a PDF is uploaded twice. When trying to overwrite or delete the existing file, the debugger tells me that the file is in use by another process.
Here's my function that returns an Image to the controller:
//path is a fully qualified path to a file ending in .PDF
private Image ConvertPDFTOneImage(string path)
{
MagickReadSettings settings = new MagickReadSettings();
settings.Density = new PointD(300, 300);
using (MagickImageCollection images = new MagickImageCollection())
{
FileInfo file = new FileInfo(path);
images.Read(file);
file = null;
using (MagickImage horizontal = images.AppendHorizontally())
{
string PNGName = Path.ChangeExtension(path, ".png");
horizontal.Write(PNGName);
}
return Image.FromFile(path.Replace("pdf", "png"));
}
}
And my controller that streams the response back to the browser:
public async Task<HttpResponseMessage> PostFormData([FromUri] int sellerID, [FromUri] int eventID, [FromUri] string section, [FromUri] string row, [FromUri] string seat)
{
if (HttpContext.Current.Request.Files.AllKeys.Any())
{
try
{
string base64 = string.Empty;
SellerObjects.Externeal.SellerTicket TicketToSave = new SellerObjects.Externeal.SellerTicket();
TicketToSave.UploadedFile = HttpContext.Current.Request.Files["UploadedImage"];
SellerTicketRepo TheLocalSellerRepo = new SellerTicketRepo(TicketToSave);
using (MemoryStream ms = new MemoryStream())
{
TheLocalSellerRepo.GetConvertedPDFImage().Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
base64 = System.Convert.ToBase64String(ms.ToArray());
}
HttpResponseMessage result = new HttpResponseMessage(HttpStatusCode.OK);
result.Content = new StringContent(base64);
result.Content.Headers.ContentType = new MediaTypeHeaderValue("image/png");
return result;
}
catch (Exception ex)
{
return Request.CreateResponse(HttpStatusCode.BadRequest, "Error saving file.");
}
}
return Request.CreateErrorResponse(HttpStatusCode.BadRequest, "An error has occurred");
}
I am assuming that the Image class that you are returning is a System.Drawing.Image. You need to Dispose this object to release the file lock.
// Instead of this:
using (MemoryStream ms = new MemoryStream())
{
TheLocalSellerRepo.GetConvertedPDFImage().Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
base64 = System.Convert.ToBase64String(ms.ToArray());
}
// Should you be doing this:
using (MemoryStream ms = new MemoryStream())
{
using (Image img = TheLocalSellerRepo.GetConvertedPDFImage())
{
img.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
base64 = System.Convert.ToBase64String(ms.ToArray());
}
}
// Or you could even do this (if GetConvertedPDFImage() returns a MagickImage):
using (MagickImage img = TheLocalSellerRepo.GetConvertedPDFImage())
{
img.Format = MagickFormat.Jpeg;
base64 = img.ToBase64();
}