如何从文本文件中的流中分配图像值

huangapple
go评论97阅读模式
英文:

How to assign an image value from a stream from a text file

问题

以下是您要翻译的部分：

"我正在尝试在一个项目中实现一个功能，允许用户上传他们自己的图像文件作为头像。我从图像中获取流并将其保存为 jpg 格式的文本文件，与用户的用户名一起保存在同一行。但是，当我尝试将图片框的图像设置为这个流时，我一直收到“参数无效”的错误消息。有没有人知道我做错了什么？

保存流到文本文件的代码：

  1. customavatar = Image.FromFile(filename);
  3. var stream = new System.IO.MemoryStream();
  4. customavatar.Save(stream, ImageFormat.Jpeg);
  5. stream.Position = 0;
  7. if (!File.Exists(textfile))
  8. {
  9.     File.Create(textfile);
  10. }
  11. using (StreamWriter sw = File.AppendText(textfile))
  12. {
  13.     sw.WriteLine("");
  14.     sw.WriteLine($"{username},{stream}");
  15. }

设置图片框图像的代码，出现错误的地方：

  1. string[] filelinesarray = File.ReadAllLines(textfile);
  2. foreach (string str in filelinesarray)
  3. {
  4.     if (str.Split(",")[0] == username)
  5.     {
  6.         byte[] byteArray = Encoding.ASCII.GetBytes(str.Split(",")[1]);
  7.         MemoryStream stream = new MemoryStream(byteArray);
  9.         Image img = Image.FromStream(stream);
  10.         picturebox.Image = img;
  11.     }
  12. }

希望这可以帮助您解决问题。

英文:

I'm trying to implement a feature in a project where the user can upload their own image files to be used as an avatar, I get the stream from the image as jpg format and save it in a text file on the same line with the user's username where it's retrieved but I keep getting the error message "Parameter is not valid" when I try to set the image of a picturebox to the stream, does anyone know what I'm doing wrong?

The code that saves the stream to the text file;

  1. customavatar = Image.FromFile(filename);
  3. var stream = new System.IO.MemoryStream();
  4. customavatar.Save(stream, ImageFormat.Jpeg);
  5. stream.Position = 0;
  7. if(!File.Exists( textfile))
  8. {
  9.     File.Create( textfile);
  10. }
  11. using (StreamWriter sw = File.AppendText( textfile))
  12. {
  13.     sw.WriteLine("");
  14.     sw.WriteLine($"{username},{stream}");
  15. }

The code setting the image of a picturebox to the stream, where the error appears;

  1. string[] filelinesarray = File.ReadAllLines(text file);
  2. foreach (string str in filelinesarray)
  3. {
  4.     if (str.Split(",")[0] == username)
  5.     {
  6.         byte[] byteArray = Encoding.ASCII.GetBytes(str.Split(",")[1]);
  7.         MemoryStream stream = new MemoryStream(byteArray);
  9.         Image img = Image.FromStream(stream);
  10.         picturebox.Image = img;
  11.     }
  12. }

答案1

得分: 1

根据Fildor的建议，使用base64对图像进行编码。

我使用winform（.Net Framework 4.8）进行了测试，并修改了您的代码。

我自定义了文本文件的保存地址和用户名的名称，并使用openfiledialog来选择需要上传的图像地址。

以下是我的演示：

  1. private void button1_Click(object sender, EventArgs e)
  2. {
  3.     var openFileDialog = new OpenFileDialog();
  4.     openFileDialog.Filter = "All Files (*.*)|*.*";
  5.     openFileDialog.Title = "Select a file";
  6.     if (openFileDialog.ShowDialog() == DialogResult.OK)
  7.     {
  8.         string filename = openFileDialog.FileName;
  9.         var stream = new System.IO.MemoryStream();
  10.         using (var customavatar = Image.FromFile(filename))
  11.         {
  12.             customavatar.Save(stream, ImageFormat.Jpeg);
  13.         }
  14.         var base64String = Convert.ToBase64String(stream.ToArray());
  16.         // 创建文件，如果文件存在则覆盖。
  17.         using (var fstream = new FileStream(textfile, FileMode.Create, FileAccess.Write, FileShare.None))
  18.         {
  19.             using (var writer = new StreamWriter(fstream))
  20.             {
  21.                 writer.Write($"{username},{base64String}");
  22.             }
  23.         }
  24.     }
  25. }
  1. private void button2_Click(object sender, EventArgs e)
  2. {
  3.     string[] filelinesarray = File.ReadAllLines(textfile);
  4.     foreach (string str in filelinesarray)
  5.     {
  6.         if (str.Split(',')[0] == username)
  7.         {
  8.             byte[] byteArray = Convert.FromBase64String(str.Split(',')[1]);
  9.             MemoryStream stream = new MemoryStream(byteArray);
  10.             Image img = Image.FromStream(stream);
  11.             pictureBox1.Image = img;
  12.         }
  13.     }
  14. }

如何从文本文件中的流中分配图像值

英文:

As Fildor said, use base 64 to encode the image.

I tested with winform (.Net Framework4.8) and modified your code.

I customized the save address of a txt file and the name of a username. And use openfiledialog to select the image address that needs to be uploaded.

The following is my demo:

  1. private void button1_Click(object sender, EventArgs e)
  2. {
  3.     var openFileDialog = new OpenFileDialog();
  4.     openFileDialog.Filter = "All Files (*.*)|*.*";
  5.     openFileDialog.Title = "Select a file";
  6.     if (openFileDialog.ShowDialog() == DialogResult.OK)
  7.     {
  8.         string filename = openFileDialog.FileName;
  9.         var stream = new System.IO.MemoryStream();
  10.         using (var customavatar = Image.FromFile(filename))
  11.         {
  12.             customavatar.Save(stream, ImageFormat.Jpeg);
  13.         }
  14.         var base64String = Convert.ToBase64String(stream.ToArray());
  16.         // Create the file, or overwrite if the file exists.
  17.         using (var fstream = new FileStream(textfile, FileMode.Create, FileAccess.Write, FileShare.None))
  18.         {
  19.             using (var writer = new StreamWriter(fstream))
  20.             {
  21.                 writer.Write($"{username},{base64String}");
  22.             }
  23.         }
  24.     }
  25. }
  1. private void button2_Click(object sender, EventArgs e)
  2. {
  3.     string[] filelinesarray = File.ReadAllLines(textfile);
  4.     foreach (string str in filelinesarray)
  5.     {
  6.         if (str.Split(',')[0] == username)
  7.         {
  8.             byte[] byteArray = Convert.FromBase64String(str.Split(',')[1]);
  9.             MemoryStream stream = new MemoryStream(byteArray);
  10.             Image img = Image.FromStream(stream);
  11.             pictureBox1.Image = img;
  12.         }
  13.     }
  14. }

如何从文本文件中的流中分配图像值

huangapple
  • 本文由 发表于 2023年2月27日 02:09:34
  • 转载请务必保留本文链接：https://go.coder-hub.com/75574040.html
  • c#
  • visual-studio
匿名

发表评论

匿名网友

:?: :razz: :sad: :evil: :!: :smile: :oops: :grin: :eek: :shock: :???: :cool: :lol: :mad: :twisted: :roll: :wink: :idea: :arrow: :neutral: :cry: :mrgreen:

确定