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C#存取SQL Server数据库之一:二进制存取图片文件

时间:2022-11-14 23:24:29 编辑:袖梨 来源:一聚教程网

创建项目

1. 添加一个名为RWTest的表到 SQL Server MYTest 数据库。 表字段设置如下:

a. 唯一标识字段名称为"ID",类型为Int

b. 名称为"Description"VarChar类型的字段,字段长度为50

c. 名称为"ImgField" Image 类型的字段。

2. 启动 Visual Studio .NET 并创建一个新的 Visual C# Windows 应用程序项目。

3. 从工具栏中拖两个Button 控件到默认窗体, Form1

4. 在属性窗口中修改NamebuttonFileToDB Text 属性为从文件保存到数据库 然后修改NamebuttonDBToFile Text 属性为从数据库保存到文件

5 从工具栏放置2TextBox1PictureBox控件:Name属性分别为:textBoxGetID, textBoxGetDescription, pictureBoxGetImage, 显示从数据库读出的IDDescriptionImgField字段。

源码实例

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Data.SqlClient;

using System.IO;

using System.Collections;

//数据库说明:MyTest数据库,RWTest,包含3列:ID(int),Description(varchar(50),ImgField(Image)

namespace RWImgSQL

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

private void buttonFileToDB_Click(object sender, EventArgs e)

{

SqlConnection sqlConnection = new SqlConnection("Data Source = liuxueqin; Initial Catalog=MyTest;Integrated Security=True");

SqlDataAdapter sqlDataAdapter = new SqlDataAdapter("Select * from RWTest", sqlConnection);

SqlCommandBuilder sqlCommandBuilder = new SqlCommandBuilder(sqlDataAdapter);

DataSet dataSet = new DataSet("RWTest");

sqlDataAdapter.MissingSchemaAction = MissingSchemaAction.AddWithKey;//确定现有 DataSet 架构与传入数据不匹配时需要执行的操作。

String CurrentExeName = System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName;

string ImageFile = System.IO.Path.GetDirectoryName(CurrentExeName) + "F1.jpg";

System.IO.FileStream fileStream = new FileStream(ImageFile, FileMode.OpenOrCreate, FileAccess.ReadWrite);

byte[] myData = new byte[fileStream.Length];

fileStream.Read(myData, 0, System.Convert.ToInt32(fileStream.Length));//从流中读取字节块,并将数据写入到该缓冲区

fileStream.Close();

try

{

sqlDataAdapter.Fill(dataSet, "RWTest");

//DataRow表示DataTable中的一行数据

System.Data.DataRow dataRow;

dataRow = dataSet.Tables["RWTest"].NewRow();

dataRow1["ID"] = 1;

dataRow1["Description"] = "This would be description text";

dataRow1["ImgField"] = myData;

dataSet.Tables["RWTest"].Rows.Add(dataRow);

sqlDataAdapter.Update(dataSet, "RWTest");

sqlConnection.Close();

MessageBox.Show("写入数据库成功!", " 信息提示", MessageBoxButtons.OK, MessageBoxIcon.Information);

}

catch (Exception ex)

{

if (sqlConnection.State == ConnectionState.Open)

{

sqlConnection.Close();

}

MessageBox.Show("写入数据库失败"+ex.Message, " 信息提示", MessageBoxButtons.OK, MessageBoxIcon.Error);

}

}

private void buttonDBToFile_Click(object sender, EventArgs e)

{

SqlConnection sqlConnection = new SqlConnection("Data Source=liuxueqin;Initial Catalog=MyTest;Integrated Security=True");

SqlDataAdapter sqlDataAdapter = new SqlDataAdapter("Select * from RWTest", sqlConnection);

SqlCommandBuilder sqlCommandBuilder = new SqlCommandBuilder(sqlDataAdapter);

DataSet dataSet = new DataSet("RWTest");

byte[] MyData = new byte[0];

sqlDataAdapter.Fill(dataSet, "RWTest");

DataRow myRow;

myRow = dataSet.Tables["RWTest"].Rows[0];

MyData = (byte[])myRow["imgField"];

int ArraySize = MyData.GetUpperBound(0);

String CurrentExeName = System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName;

string ImageFile = System.IO.Path.GetDirectoryName(CurrentExeName) + "F2.jpg";

FileStream fs = new FileStream(ImageFile, FileMode.OpenOrCreate, FileAccess.Write);

fs.Write(MyData, 0, ArraySize);

fs.Close();

//---在界面上的2textBox1pictureBox,用来显示从数据库中读出的IDDescriptionImageField字段

textBoxGetID.Text = myRow["ID"].ToString();

textBoxGetDescription.Text = myRow["Description"].ToString();

pictureBoxGetImage.Image = Image.FromFile(ImageFile);

if (sqlConnection.State == ConnectionState.Open)

{

sqlConnection.Close();

}

MessageBox.Show(" 从数据库读出数据成功!", " 信息提示", MessageBoxButtons.OK, MessageBoxIcon.Information);

}

}

}



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