C# 从数据库加载 PictureBox 图像
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Loading PictureBox Image From Database
提问by aliprogrammer
i'm trying to load images from database to a PictureBox. I use these following codes in order to load them to my picture. I've written some code but don't know what I should do for continuing.
我正在尝试将图像从数据库加载到PictureBox. 我使用以下这些代码将它们加载到我的图片中。我写了一些代码，但不知道我应该怎么做才能继续。
Any help will be appreciated.
任何帮助将不胜感激。
private void button1_Click(object sender, EventArgs e)
{
sql = new SqlConnection(@"Data Source=PC-PC\PC;Initial Catalog=Test;Integrated Security=True");
cmd = new SqlCommand();
cmd.Connection = sql;
cmd.CommandText = ("select Image from Entry where EntryID =@EntryID");
cmd.Parameters.AddWithValue("@EntryID", Convert.ToInt32(textBox1.Text));
}
采纳答案by Mario Sannum
Continue with something like this in the button1_Click:
继续在 button1_Click 中执行类似的操作：
// Your code first, here.
var da = new SqlDataAdapter(cmd);
var ds = new DataSet();
da.Fill(ds, "Images");
int count = ds.Tables["Images"].Rows.Count;
if (count > 0)
{
var data = (Byte[])ds.Tables["Images"].Rows[count - 1]["Image"];
var stream = new MemoryStream(data);
pictureBox1.Image = Image.FromStream(stream);
}
回答by GoRoS
Assuming we have a simple database with a table called BLOBTest:
假设我们有一个简单的数据库，其中包含一个名为 的表BLOBTest：
CREATE TABLE BLOBTest
(
BLOBID INT IDENTITY NOT NULL,
BLOBData IMAGE NOT NULL
)
We could retrieve the image to code in the following way:
我们可以通过以下方式检索图像以进行编码：
try
{
SqlConnection cn = new SqlConnection(strCn);
cn.Open();
//Retrieve BLOB from database into DataSet.
SqlCommand cmd = new SqlCommand("SELECT BLOBID, BLOBData FROM BLOBTest ORDER BY BLOBID", cn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds, "BLOBTest");
int c = ds.Tables["BLOBTest"].Rows.Count;
if(c>0)
{ //BLOB is read into Byte array, then used to construct MemoryStream,
//then passed to PictureBox.
Byte[] byteBLOBData = new Byte[0];
byteBLOBData = (Byte[])(ds.Tables["BLOBTest"].Rows[c - 1]["BLOBData"]);
MemoryStream stmBLOBData = new MemoryStream(byteBLOBData);
pictureBox1.Image= Image.FromStream(stmBLOBData);
}
cn.Close();
}
catch(Exception ex)
{MessageBox.Show(ex.Message);}
This code retrieves the rows from the BLOBTesttable in the database into a DataSet, copies the most recently added image into a Bytearray and then into a MemoryStreamobject, and then loads the MemoryStreaminto the Imageproperty of the PictureBoxcontrol.
此代码BLOBTest将数据库中表中的行检索到一个 中DataSet，将最近添加的图像复制到一个Byte数组中，然后再复制到一个MemoryStream对象中，然后将其加载MemoryStream到控件的Image属性中PictureBox。
Full reference guide:
完整参考指南：
回答by Shailendra Mishra
private void btnShowImage_Click(object sender, EventArgs e)
{
string constr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=.\PIS(ACU).mdb;";
Con = new OleDbConnection(@constr);
Con.Open();
Com = new OleDbCommand();
Com.Connection = Con;
Com.CommandText = "SELECT Photo FROM PatientImages WHERE Patient_Id = " + val + " ";
OleDbDataReader reader = Com.ExecuteReader();
if (reader.Read())
{
byte[] picbyte = reader["Photo"] as byte[] ?? null;
if (picbyte != null)
{
MemoryStream mstream = new MemoryStream(picbyte);
pictureBoxForImage.Image = System.Drawing.Image.FromStream(mstream);
{
System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(mstream);
}
}
