图像到字节到字符串 [英] Image to byte to string

问题描述

您好！我现在能够将DB中的图像保存并查看为字节，现在我需要将其转换为字符串，我收到错误。任何帮助或更正将不胜感激。谢谢。



我尝试了什么：



private void button1_Click （对象发送者，EventArgs e）

{

图像myImage = pictureBox1.Image;

byte []数据;

using（MemoryStream ms = new MemoryStream（））

{

myImage.Save（ms，System.Drawing.Imaging.ImageFormat.Jpeg）;

data = ms.ToArray（）;

string s3 = Convert.ToBase64String（data）;

data = Convert.FromBase64String（s3）;

}







con.Open（）;

cmd = new SqlCommand（INSERT INTO kenny（id，picture）VALUES（@ id，@ IM），con）;

{

cmd.Parameters。 AddWithValue（@ IM，s3）;

cmd.Parameters.AddWithValue（@ id，textBox1.Text）;
cmd.ExecuteNonQuery（）;

}

con.Close（）;

}

Hello! I am now able to save and view Image from DB as a byte, now I need to convert it into string and I am receiving error. Any help or correction will be appreciated. Thank you.

What I have tried:

private void button1_Click(object sender, EventArgs e)
{
Image myImage = pictureBox1.Image;
byte[] data;
using (MemoryStream ms = new MemoryStream())
{
myImage.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
data = ms.ToArray();
string s3 = Convert.ToBase64String(data);
data = Convert.FromBase64String(s3);
}



con.Open();
cmd = new SqlCommand("INSERT INTO kenny (id,picture) VALUES (@id,@IM)", con);
{
cmd.Parameters.AddWithValue("@IM", s3);
cmd.Parameters.AddWithValue("@id", textBox1.Text);
cmd.ExecuteNonQuery();
}
con.Close();
}

推荐答案

拜托，帮自己一个忙，回顾一下C＃基础知识：这是我本周末第三次看到这段代码，而你正在做的是犯了一个根本性的错误 - 然后忽略你得到的错误信息。

s3 是 button1_Click 方法中的局部变量：

Please, do yourself a favour and review the C# basics: this is the third time I've seen that code this weekend, and what you are doing is making a fundamental mistake - then ignoring the error message you get.
s3 is a local variable in the button1_Click method:

private void button1_Click(object sender, EventArgs e)
    {
    Image myImage = pictureBox1.Image;
    byte[] data;
    using (MemoryStream ms = new MemoryStream())
        {
        myImage.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
        data = ms.ToArray();
        string s3 = Convert.ToBase64String(data);
        data = Convert.FromBase64String(s3);
        }

并且它的范围仅限于声明它的代码块：包含大括号的集合。

因此，它不存在在你的之外使用块，并且你得到编译器错误。

使用之外c>阻止，它将编译：

And it's scope is restricted to the code block in which it is declared: the containing set of curly brackets.
As such, it doesn't exist outside your using block, and you get a compiler error.
Move the definition outside the using block, and it will compile:

private void button1_Click(object sender, EventArgs e)
    {
    Image myImage = pictureBox1.Image;
    byte[] data;
    string s3;
    using (MemoryStream ms = new MemoryStream())
        {
        myImage.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
        data = ms.ToArray();
        s3 = Convert.ToBase64String(data);
        data = Convert.FromBase64String(s3);
        }

这篇关于图像到字节到字符串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！