XML  

Reading and Manipulating an Xml file Using C#.Net (Including Images)

Objective

To develop a Windows application to read an xml file; perform insert, search, update, and delete operations, and navigation of records and display respective images.

Design

Reading and manipulating

Design the form as above with 1 DataGridView, 1 PictureBox control, 2 OpenFileDialog controls, 4 Labels, 4 TextBoxes, and 12 Buttons.

PictureBox1 Properties

BorderStyle = Fixed3D;
SizeMode = StrechImage;
C#

Code

using System;
using System.Data;
using System.Drawing;
using System.Windows.Forms;
using Microsoft.VisualBasic;
using System.IO;
namespace xmlapp
{
    public partial class studdata : Form
    {
        public studdata()
        {
            InitializeComponent();
        }
        DataSet ds; string fpath, fdir, ppath, pname, pdestin; int rno = 0; DataRow drow;
        private void loadbtn_Click(object sender, EventArgs e)
        {
            try
            {
                openFileDialog1.Filter = "xml|*.xml|all files|*.*";
                DialogResult res = openFileDialog1.ShowDialog();
                if (res == DialogResult.OK)
                {
                    dataGridView1.DataSource = null;
                    clearbtn.PerformClick();
                    fpath = openFileDialog1.FileName;
                    ds = new DataSet();
                    ds.ReadXml(fpath);
                    ds.Tables[0].Constraints.Add("pk_sno", ds.Tables[0].Columns[0], true);
                    dataGridView1.DataSource = ds.Tables[0];
                    fdir = fpath.Substring(0, fpath.LastIndexOf("\\") + 1);
                    showdata();
                }
            }
            catch
            { MessageBox.Show("invalid input");  }
        }
        void showdata()
        {
            if (ds.Tables[0].Rows.Count > 0)
            {
                pictureBox1.Image = null;
                sno_txtbx.Text = ds.Tables[0].Rows[rno][0].ToString();
                sname_txtbx.Text = ds.Tables[0].Rows[rno][1].ToString();
                course_txtbx.Text = ds.Tables[0].Rows[rno][2].ToString();
                fee_txtbx.Text = ds.Tables[0].Rows[rno][3].ToString();
                pictureBox1.ImageLocation = fdir + ds.Tables[0].Rows[rno][4].ToString();
            }
            else
                MessageBox.Show("No records");
        }
        private void browsebtn_Click(object sender, EventArgs e)
        {
            openFileDialog2.InitialDirectory = fdir;
            openFileDialog2.Filter = "bmp,jpeg,png|*.bmp;*.jpg;*.png|all files|*.*";
            DialogResult res = openFileDialog2.ShowDialog();
            if (res == DialogResult.OK)
            {
                pictureBox1.ImageLocation = openFileDialog2.FileName;
            }
        }
        private void insertbtn_Click(object sender, EventArgs e)
        {
            drow = null;
            drow = ds.Tables[0].Rows.Find(sno_txtbx.Text);
            if (drow == null)
            {
                drow = ds.Tables[0].NewRow();
                drow[0] = sno_txtbx.Text;
                drow[1] = sname_txtbx.Text;
                drow[2] = course_txtbx.Text;
                drow[3] = fee_txtbx.Text;
                phototask();
                drow[4] = pname;
                ds.Tables[0].Rows.Add(drow);
                rno = ds.Tables[0].Rows.IndexOf(drow);
                ds.WriteXml(fpath);
                MessageBox.Show("record inserted");
            }
            else
                MessageBox.Show("sno. should be unique");
        }
        void phototask()
        {
            ppath = pictureBox1.ImageLocation;
            pname = sno_txtbx.Text + ")" + (ppath.Substring(ppath.LastIndexOf('\\') + 1));
            pdestin = fdir + pname;
            pictureBox1.Image.Save(pdestin);
        }
        private void searchbtn_Click(object sender, EventArgs e)
        {
            int n = Convert.ToInt32(Interaction.InputBox("Enter sno to search:", "Search", "10", 200, 200));
            drow = null;
            drow = ds.Tables[0].Rows.Find(n);
            if (drow != null)
            {
                rno = ds.Tables[0].Rows.IndexOf(drow);
                sno_txtbx.Text = drow[0].ToString();
                sname_txtbx.Text = drow[1].ToString();
                course_txtbx.Text = drow[2].ToString();
                fee_txtbx.Text = drow[3].ToString();
                pictureBox1.ImageLocation = fdir + drow[4];
            }
            else
                MessageBox.Show("record not found");
        }
        private void updatebtn_Click(object sender, EventArgs e)
        {
            DataRow drow = ds.Tables[0].Rows.Find(sno_txtbx.Text);
            if (drow!= null)
            {
                rno = ds.Tables[0].Rows.IndexOf(drow);
                ds.Tables[0].Rows[rno][0] = sno_txtbx.Text;
                ds.Tables[0].Rows[rno][1] = sname_txtbx.Text;
                ds.Tables[0].Rows[rno][2] = course_txtbx.Text;
                ds.Tables[0].Rows[rno][3] = fee_txtbx.Text;
                File.Delete(fdir + drow[4]);
                phototask();
                ds.Tables[0].Rows[rno][4] = pname;
                ds.WriteXml(fpath);
                MessageBox.Show("record updated");
            }
            else
                MessageBox.Show("no record exists with this sno.");
        }
        private void deletebtn_Click(object sender, EventArgs e)
        {
            DataRow drow = ds.Tables[0].Rows.Find(sno_txtbx.Text);
            if (drow!= null)
            {
                File.Delete(fdir + drow[4]);
                ds.Tables[0].Rows.Remove(drow);
                ds.WriteXml(openFileDialog1.FileName);
                MessageBox.Show("record deleted");
                rno = 0;
                showdata();
            }
            else
                MessageBox.Show("no record exists with this sno.");
        }
        private void firstbtn_Click(object sender, EventArgs e)
        {
            rno = 0;
            showdata();
        }
        private void prevbtn_Click(object sender, EventArgs e)
        {
            if (rno > 0)
            {
                rno--;
                showdata();
            }
            else
            { MessageBox.Show("first record"); }
        }
        private void nextbtn_Click(object sender, EventArgs e)
        {
            if (rno < ds.Tables[0].Rows.Count - 1)
            {
                rno++;
                showdata();
            }
            else
            { MessageBox.Show("LastRecord"); }
        }
        private void lastbtn_Click(object sender, EventArgs e)
        {
            rno = ds.Tables[0].Rows.Count - 1;
            showdata();
        }
        private void clearbtn_Click(object sender, EventArgs e)
        {
            sno_txtbx.Text = sname_txtbx.Text = course_txtbx.Text = fee_txtbx.Text = "";
            pictureBox1.Image = null;
        }
        private void exitbtn_Click(object sender, EventArgs e)
        {
            this.Close();
        }
    }
}
C#

Note. In this application, we will search a record by taking input from the InputBox. For this, we have to add a reference to Microsoft.VisualBasic.

Adding a reference

  • Goto Project Menu->Add Reference -> select 'Microsoft.VisualBasic' from the .NET tab.
  • To use this we have to include the namespace: 'using Microsoft.VisualBasic'
  • XML files and respective JPEG images should be maintained in the same folder.

Creating an XML file

Example for Creating an XML file

Open Notepad and type the following & save it with the extension '.xml'.

<students>
  <student>
    <sno>10</sno>
    <sname>Prashanth</sname>
    <course>dotnet</course>
    <fee>3500</fee>
    <photo>10)prash.jpg</photo>
  </student>
  <student>
    <sno>20</sno>
    <sname>Aravind</sname>
    <course>oracle</course>
    <fee>1000</fee>
    <photo>20)aravind.jpg</photo>
  </student>
  <student>
    <sno>30</sno>
    <sname>Satyapal</sname>
    <course>java</course>
    <fee>3000</fee>
    <photo>30)satya.jpg</photo>
  </student>
  <student>
    <sno>40</sno>
    <sname>Mahender</sname>
    <course>php</course>
    <fee>2500</fee>
    <photo>40)mahi.jpg</photo>
  </student>
</students>
XML

Execution

To execute the application click the loadxml button and select an xml file (a folder 'student data' consisting of the xml file is placed in 'xmlapp.zip' along with source code)

Another way of handling XML file

Performing operations on xml files and saving changes, which includes creating xml elements(tags), assigning values, and appending them to xml root elements.

(for this we have to include namespace 'using System.Xml')

Insert a record

For example to insert a record

XmlDocument doc = new XmlDocument();
doc.Load(openFileDialog1.FileName);
XmlElement root = doc.CreateElement("student");
XmlElement sno = doc.CreateElement("sno");
XmlElement sname = doc.CreateElement("sname");
XmlElement course = doc.CreateElement("course");
XmlElement fee = doc.CreateElement("fee");
XmlElement photo = doc.CreateElement("photo");
sno.InnerText = sno_txtbx.Text;
sname.InnerText = sname_txtbx.Text;
course.InnerText = course_txtbx.Text;
fee.InnerText = fee_txtbx.Text;
phototask(); // Refer 'Code' for phototask()
photo.InnerText = pname;
root.AppendChild(sno);
root.AppendChild(sname);
root.AppendChild(course);
root.AppendChild(fee);
root.AppendChild(photo);
doc.DocumentElement.AppendChild(root);
doc.Save(fdir);
MessageBox.Show("record inserted");
C#


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