how to send fields (Database Access) in Arrey

Accepted answer

OK, I've altered it to fit in with your existing declarations:

public static string Albumstring = string.Format(@"Provider = Microsoft.Jet.OLEDB.4.0;Data Source = {0}\Data.mdb", Application.StartupPath.ToString());

OleDbConnection con = new OleDbConnection(Albumstring);

OleDbCommand com = null;

private int index = 0;

private List picList;

private void Form2_Load(object sender, EventArgs e)

{

picList = new List();

string cmdString = "SELECT Pic, Sub, Alb FROM Aks";

con.Open();

com = new OleDbCommand(cmdString, con);

var reader = com.ExecuteReader();

while (reader.Read())

{

byte[] bytes = (byte[])reader["Pic"];

var ms = new System.IO.MemoryStream(bytes);

Image pic = Image.FromStream(ms);

string sub = reader["Sub"].ToString();

string alb = reader["Alb"].ToString();

var picData = new PicData(pic, sub, alb);

picList.Add(picData);

}

reader.Close();

con.Close();

button2.PerformClick();

}

ghasem deh12y ago

thank you ... MessageBox Error Again ---- Forget this ! ---- thanks

Vulpes12y ago

I can't find anything wrong with the code but you don't appear to be actually displaying the image found or the first such image.

Try making the highlighted changes:

private void textBox1_Leave(object sender, EventArgs e)

{

picList = new List();

if (textBox1.Text.Trim() == "") return;

string Albumstring = "SELECT Pic, Sub, Alb, Date FROM Pic WHERE Alb='" + textBox1.Text + "'";

com.Parameters.Clear();

// com.Parameters.AddWithValue("a", textBox1.Text.Trim());

con.Open();

com = new OleDbCommand(Albumstring, con);

var reader = com.ExecuteReader();

while (reader.Read())

{

byte[] bytes = (byte[])reader["Pic"];

var ms = new System.IO.MemoryStream(bytes);

Image pic = Image.FromStream(ms);

string alb = reader["Alb"].ToString();

string sub = reader["Sub"].ToString();

string dat = reader["Date"].ToString();

var picData = new PicData(pic, sub, alb, dat);

picList.Add(picData);
}

reader.Close();

con.Close();
index = 0;
if (picList.Count > 0)
{
Next_Click(null, null);
}
else
{
pictureBox1.Image = null;
}
}

ghasem deh12y ago

not happen !

Vulpes12y ago

You still have the code in textBox1_TextChanged.

Try putting it in textBox1_Leave instead.

ghasem deh12y ago

excuse me for get your time
this code NO error ... But not happen !

private void textBox1_TextChanged(object sender, EventArgs e)

{

picList = new List();

if (textBox1.Text.Trim() == "") return;

string Albumstring = "SELECT Pic, Sub, Alb, Date FROM Pic WHERE Alb='" + textBox1.Text + "'";

com.Parameters.Clear();

// com.Parameters.AddWithValue("a", textBox1.Text.Trim());

con.Open();

com = new OleDbCommand(Albumstring, con);

var reader = com.ExecuteReader();

while (reader.Read())

{

byte[] bytes = (byte[])reader["Pic"];

var ms = new System.IO.MemoryStream(bytes);

Image pic = Image.FromStream(ms);

string alb = reader["Alb"].ToString();

string sub = reader["Sub"].ToString();

string dat = reader["Date"].ToString();

var picData = new PicData(pic, sub, alb, dat);

picList.Add(picData);

}

reader.Close();

con.Close();

Vulpes12y ago

I've noticed now that you've got the code for this in the textBox1_TextChanged handler so it will be executed each time the user types (or deletes) a character or the Text property is set programatically!

Worse still, as 'com' is defined at class level, a new parameter will be added each time the TextChanged event is fired.

Ideally, this code should be in a button_Click handler but you could also put it in textBox1's Leave handler so that it won't be executed until the user has finished typing and moved the input focus to a new control.

I'd also make some changes:

1. Insert this line at the beginning so the code won't execute if the textbox is blank:

if(textBox1.Text.Trim() == "") return;

2. Just before this line:

com.parameters.AddWithValue("a", textBox1.Text);

clear out any previous parameters by inserting this line:

com.Parameters.Clear();

3. Make sure there's no superfluous whitespace by replacing this line:

com.Parameters.AddWithValue("a", textBox1.Text);

with this one:

com.Parameters.AddWithValue("a", textBox1.Text.Trim());

4. If you still get an error, then forget about parameters (at least for the time being) and replace these lines:

string cmdString = "SELECT Pic, Sub, Alb FROM Aks WHERE Alb=?";

com.Parameters.Clear();

com.Parameters.AddWithValue("a", textBox1.Text.Trim());

with this one:

string cmdString = "SELECT Pic, Sub, Alb FROM Aks WHERE Alb='" + textBox1.Text + "'";

ghasem deh12y ago

post 25 (iamge) --- massegBox Error !

Vulpes12y ago

What's the error this time?

ghasem deh12y ago

thanks for answer show massageBox ERROR again ...

Vulpes12y ago

Sorry, it should be an upper case 'P':

com.Parameters.AddWithValue("a", textBox1.Text);

ghasem deh12y ago

now this ERROR ...

Vulpes12y ago

Ah, it's just dawned on me that you're using MS Access here which (unlike SQL Server) doesn't use @ as the parameter prefix in the query itself. It uses ? instead but identifies parameters by their positions in the parameter collection rather than their names.

Try this instead:

string cmdString = "SELECT Pic, Sub, Alb FROM Aks WHERE Alb=?";

com.parameters.AddWithValue("a", textBox1.Text);

ghasem deh12y ago

hi ...
this ERROR

Vulpes12y ago

The query looks OK.

What error are you getting?

ghasem deh12y ago

How to search by album ?
i use this code :

string cmdString = "SELECT Pic, Sub, Alb FROM Aks WHERE Alb=@a";
com.parameters.AddWithValue("@a", textBox1.Text);

but --> ERROR !
i want display pic Based on Album name ...

Vulpes12y ago

Well, this is quite a common pattern when you need to display successive elements of a collection in Windows Forms programming and so I suppose you could try and remember what to do if it crops up again.

However, personally, I never try to remember stuff such as this. I just work out the logic from first principles each time it's needed. That way I can deal with any variations that might occur as you usually find that no two situations in computing are exactly the same.

ghasem deh12y ago

thank you very much ... :)
how to me learn it ?

Vulpes12y ago

If you'd like it to work in a similar way to the Next button, except in the reverse direction, then try this:

private void Perview_Click(object sender, EventArgs e)

{

index--;

if (index < 0) index = picList[picList.Count - 1]; // wrap to last image

pictureBox1.Image = picList[index].Pic;

label2.Text = picList[index].Sub;

label1.Text = picList[index].Alb;

label3.Text = picList[index].Date;

}

ghasem deh12y ago

this code :

private void Next_Click(object sender, EventArgs e)

{

pictureBox1.Image = picList[index].Pic;

label2.Text = picList[index].Sub;

label1.Text = picList[index].Alb;

label3.Text = picList[index].Date;

index++;

if (index >= picList.Count) index = 0;

}

private void Perview_Click(object sender, EventArgs e)

{

try

{

if (index < picList.Count)

{

index--;

pictureBox1.Image = picList[index].Pic;

label2.Text = picList[index].Sub;

label1.Text = picList[index].Alb;

label3.Text = picList[index].Date;

if (index == 0) Perview.Enabled = false;

}

catch

{

MessageBox.Show("????? ?? ???? ? ???? ????? ???? ??????","Error",MessageBoxButtons.OK,MessageBoxIcon.Error);

}

Vulpes12y ago

Can you post the code you currently have for the preview button please.

ghasem deh12y ago

hi ...
Vulpes you are here ?
this project (TEST) ... Next key OK but Perview key when click on (last image in array) error !
if 10 image in database , Perview from image 9 ... ok BUT from image 10 send erro !

Vulpes12y ago

If you want to move backwards, rather than back to the beginning, when the end of the list is reached, then I'd use this code:

// declare additonal field

bool moveBack = false;

private void btnNext_Click(object sender, EventArgs e)

{

pictureBox1.Image = picList[index].Pic;

label1.Text = picList[index].Sub;

label2.Text = picList[index].Alb;

if (!moveBack)

{

index++;

if (index >= picList.Count)

{

moveBack = true;

index = picList.Count - 2;

if (index < 0) index = 0;

}

else

{

index--;

if (index < 0)

{

moveBack = false;

index = 1;

if (index >= picList.Count) index = 0;

}

ghasem deh12y ago

you are best ...
i write this code to Perview Key :

pictureBox1.Image = picList[index].Pic;
            label1.Text = picList[index].Sub;
            label2.Text = picList[index].Alb;
            index--;
            if (index <= picList.Count) index = 0;

But only a picture to go back ... error

ghasem deh12y ago

error again ...

this my project

I'm confused ... please checked !

Vulpes12y ago

This line:

var picList = new List();

should be:

picList = new List(); // now assigning to field

The warning should now go away.

ghasem deh12y ago

this my connection :

public static string Albumstring = string.Format(@"Provider = Microsoft.Jet.OLEDB.4.0;Data Source = {0}\Data.mdb", Application.StartupPath.ToString());
        OleDbConnection con = new OleDbConnection(Albumstring);
        OleDbCommand com = new OleDbCommand();

and change (Date) to (Alb = Text) ...

Error Pic

and :
private List picList; ==>

Warning    1    Field 'Scanner_Test.Form2.picList' is never assigned to, and will always have its default value null

Vulpes12y ago

Not doing very well here, am I?

The 'i' should be 'index':

pictureBox1.Image = picList[index].Pic;

lblSub.Text = picList[index].Sub;

lblDate.Text = picList[index].Date.ToShortDateString();

index++;

if (index >= picList.Count) index = 0;

ghasem deh12y ago

Thank you for attention and Answers ...
----------------------------------------

int i;
pictureBox1.Image = picList[i].Pic;
lblSub.Text = picList[i].Sub;
lblDate.Text = picList[i].Date.ToShortDateString();
index++;
if (index >= picList.Count) index = 0;
Error : Error 1 Use of unassigned local variable 'i'

Vulpes12y ago

Sorry, it should be:

private List picList;

I'm writing this stuff off the top of my head and so mistakes, unfortunately, are inevitable.

ghasem deh12y ago

excuse me !
private List<picData> picList;
Error :
Error 1 The type or namespace name 'picData' could not be found (are you missing a using directive or an assembly reference?)

Vulpes12y ago

Add this using directive at the top of the class file as it doesn't look like it's added by default:

using System.Drawing;

ghasem deh12y ago

public Image Pic {get; set;}
public string Sub {get; set;}
public DateTime Date {get; set;}

public PicData(Image pic, string sub, DateTime date)
{
Pic = pic;
Sub = sub;
Date = date;
}

Error :
Error 1 The type or namespace name 'Image' could not be found (are you missing a using directive or an assembly reference?)

Vulpes12y ago

I'd create a separate class to hold the image data:

class PicData
{
public Image Pic {get; set;}
public string Sub {get; set;}
public DateTime Date {get; set;}

public PicData(Image pic, string sub, DateTime date)
{
Pic = pic;
Sub = sub;
Date = date;
}
}

If the image is now a BLOB rather than an Ole Object in the Access database, the code in your form class will be along the following lines:

private int index = 0;
private List<PicData> picList; // EDITED

private void Form1_Load(object sender, EventArgs e)
{
var picList = new List();
string conString = "whatever";
var con = new OleDbConnection(conString);
string cmdString = "SELECT pic, sub, date FROM sometable";
con.Open();
var cmd = new OleDbCommand(cmdString, con);
var reader = cmd.ExecuteReader();

while(reader.Read())
{
byte[] bytes = (byte[])reader["pic"];
var ms = new System.IO.MemoryStream(bytes);
Image pic = Image.FromStream(ms);
string sub = reader["sub"].ToString();
DateTime date = Convert.ToDateTime(reader["date"].ToString());
var picData = new PicData(pic, sub, date);
picList.Add(picData);
}

reader.Close();
con.Close();
btnNext.PerformClick(); // load first image
}

private void btnNext_Click(object sender, EventArgs e) // EDITED
{
pictureBox1.Image = picList[index].Pic; // EDITED
lblSub.Text = picList[index].Sub; // EDITED
lblDate.Text = picList[index].Date.ToShortDateString(); // EDITED
index++;
if (index >= picList.Count) index = 0;
}

ghasem deh12y ago

with bitMap method convert to binary and insert into table . now , i want read from table (with arrey) and show in form ...

Guest User12y ago

generally PICs are stored into BLOB and other similar data types because they store it as binary. I think if you've OLE object then you need to first convert into binary and then store into BLOB datatype.