将图像文件保存到sql Server并将字节数组转换为图像
本文关键字：图像 字节数 数组 转换 字节 Server 文件 保存 sql | 更新日期: 2023-09-27 18:20:29
我将图像存储在数据库中，并希望将它们从字节数组转换为图像。我将对象转换为字节数组没有问题，但在尝试从字节数组转换为图像时，我收到了"参数无效"的错误。我传递给方法的对象来自数据集行。
存储过程
USE [----------------]
GO
/****** Object: StoredProcedure [dbo].[usp_imageloader_add_test] Script Date: 01/16/2012 09:19:46 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER procedure [dbo].[usp_imageloader_add_test]
@p_Image Image
as
INSERT into Test_Images VALUES(@p_Image)
上传文件控件/将图像文件转换为字节数组并将数据保存到数据库
protected void btnUpload_Click(object sender, EventArgs e)
{
if (ctrlUpload.PostedFile != null)
{
if (ctrlUpload.PostedFile.ContentLength > 0)
{
// Get Posted File
HttpPostedFile objHttpPostedFile = ctrlUpload.PostedFile;
// Find its length and convert it to byte array
int ContentLength = objHttpPostedFile.ContentLength;
// Create Byte Array
byte[] bytImg = new byte[ContentLength];
// Read Uploaded file in Byte Array
objHttpPostedFile.InputStream.Read(bytImg, 0, ContentLength);
using (SqlConnection dbConnection = new SqlConnection(app_settings.sql_conn_string_db))
{
try
{
string sql = "usp_imageloader_add_test";
SqlCommand cmd = new SqlCommand(sql, dbConnection);
cmd.CommandType = System.Data.CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("@p_Image", bytImg).SqlDbType = SqlDbType.Binary;
cmd.Connection.Open();
cmd.ExecuteNonQuery();
cmd.Connection.Close();
}
catch (Exception ex)
{
ex.Message.ToString();
}
}
}
}
}
调用objToImg方法的表方法
protected void Page_Load(object sender, EventArgs e)
{
generateTable(false);
}
private Table generateTable(bool flag)
{
Table tb = BuildList(GetData(), flag);
if (imgloadercms != null)
{
PlaceHolder ph = new PlaceHolder();
StringBuilder sb = new StringBuilder();
ph.Controls.Add(new LiteralControl(sb.ToString()));
}
imgloadercms.Controls.Add(tb);
return tb;
}
protected Table BuildList(DataTable tb, bool flag)
{
Table tblImageLibrary = new Table();
tblImageLibrary.BorderStyle = BorderStyle.Solid;
tblImageLibrary.BorderWidth = Unit.Pixel(8);
if (tb.Rows.Count > 0)
{
try
{
if (!flag)
{
tblImageLibrary.BorderColor = Color.Black;
tblImageLibrary.BorderWidth = Unit.Pixel(1);
TableRow tr = new TableRow(); // Table row for header of table
tr.BackColor = Color.LightBlue;
TableCell c1 = new TableCell();
TableCell c2 = new TableCell();
c1.Controls.Add(new LiteralControl("Image Id"));
tr.Cells.Add(c1);
c2.Controls.Add(new LiteralControl("Image"));
tr.Cells.Add(c2);
tblImageLibrary.Rows.Add(tr);
}
int i = 0;
foreach (DataRow r in tb.Rows) // Create new row foreach row in table
{
TableRow tr = new TableRow();
if (i % 2 == 0)
{
tr.BackColor = Color.LightYellow;
}
// Build cells
TableCell c1 = new TableCell();
TableCell c2 = new TableCell();
c2.Width = 300;
c1.Controls.Add(new LiteralControl(r["Image_Id"].ToString()));
tr.Cells.Add(c1);
// Call method to serialize obj to byte array
//System.Drawing.Image dbImg =
ObjToImg(r["Image_File"]);
}
catch (Exception ex)
{
ex.ToString();
}
if (!flag)
{
}
}
return tblImageLibrary;
}
返回图像
private System.Drawing.Image ObjToImg(object obj)
{
//byte[] byteArray = null;
if (obj == null)
return null;
else
{
BinaryFormatter bf = new BinaryFormatter();
using (MemoryStream ms = new MemoryStream())
{
bf.Serialize(ms, obj); //now in Memory Stream
ms.ToArray(); // Array object
ms.Seek(0, SeekOrigin.Begin);
//return (System.Drawing.Image)bf.Deserialize(ms);
System.Drawing.Image myImage = (System.Drawing.Image)bf.Deserialize(ms);
return myImage;
}
每当我试图将内存流对象添加到图像对象构造函数时，我都会收到"Parameter is not valid"的错误消息。也许我在将字节数组插入数据库时犯了一个错误，因为我已经查看了其他代码，但它不起作用是没有意义的。
尝试使用BinaryFormatter首先从字节数组中反序列化对象！
尝试使用以下两种方法：
private System.Drawing.Image ObjToImg(byte[] obj)
{
if (obj == null)
return null;
else
{
BinaryFormatter bf = new BinaryFormatter();
using(MemoryStream ms = new MemoryStream(obj))
{
return (System.Drawing.Image)bf.Deserialize(ms);
}
}
}
private byte[] ImgToObj(System.Drawing.Image obj)
{
if (obj == null)
return null;
else
{
BinaryFormatter bf = new BinaryFormatter();
using(MemoryStream ms = new MemoryStream())
{
bf.Serialize(ms, obj);
return ms.ToArray();
}
}
}
我最近不得不在VB.NET中做同样的事情。这是我的代码，通过Telerik的代码转换器运行。这是一个相当棘手的开始工作，老实说仍然是一个痛苦。
上传图像：
private bool uploadImage(ref Bitmap p)
{
SqlConnection con = new SqlConnection();
con.ConnectionString = Configuration.ConfigurationManager.ConnectionStrings("ConnStringHere").ConnectionString;
SqlCommand cmd = new SqlCommand();
cmd.CommandText = "INSERT INTO Table_Name (File2) VALUES (@File2)"; //I named the column File2 simply because "File" seemed to be a keyword in SQLServer
cmd.CommandType = CommandType.Text;
cmd.Connection = con;
SqlParameter File1 = new SqlParameter("@File2", SqlDbType.Image);
MemoryStream ms = new MemoryStream();
using (Bitmap tempImage = new Bitmap(p))
{
tempImage.Save(ms, p.RawFormat);
}
byte[] data = ms.GetBuffer();
if (!isValidImage(data)) //optional, will include code if requested.
{
return false;
}
File1.Value = data;
cmd.Parameters.Add(File1);
con.Open();
int result = cmd.ExecuteNonQuery();
if (result > 0)
{
// SUCCESS!
con.Close();
return true;
}
else
{
//failure
con.Close();
return false;
}
}
检索图像：
private Bitmap retrieveBitmap()
{
Image image1 = null
if (dt1.Rows.Count > 0)
{
byte[] imageData1 = null;
if (dt1[0].Count > 0)
{
if (!Information.IsDBNull(dt1.CopyToDataTable()[0].Item("File2")))
{
imageData1 = (byte[])dt1.CopyToDataTable()[0].Item("File2");
}
}
if ((imageData1 != null))
{
if (isValidImage(imageData1))
{
using (MemoryStream ms = new MemoryStream(imageData1, 0, imageData1.Length))
{
ms.Write(imageData1, 0, imageData1.Length);
image1 = Image.FromStream(ms, true);
}
return image1;
}
else
{
// "Invalid image on server";
return null;
}
}
}
}
我的代码可能需要小的格式更改，请编辑任何无效语法的代码（我的C#有点生疏，我的代码是通过转换器运行的）。