Al Programming

Wednesday, December 11, 2013

Delete row from DataTable using LINQ VB.NET example

VB.NET > DataTable > Delete row with LINQ

Here is an example of deleting row from DataTable (dt) supposing you want to delete the row with id 1.

Dim row As DataRow = dt.AsEnumerable().SingleOrDefault(Function(r) r(0) = 1)

If Not row Is Nothing Then

row.Delete()
End If

Add AutoIncrement Row Values to DataTable Having AutoIncrement and PrimaryKey DataColumn

VB.NET > DataGridView > Add AutoIncrement Row Values

Example how to add AutoIncrement and PrimaryKey DataColumn values to DataTable

VB.NET

Dim dt As DataTable = New DataTable

dt.Columns.Add("ID", GetType(Integer))

dt.PrimaryKey = New DataColumn() {dt.Columns("ID")}
dt.Columns("ID").AutoIncrement = True
dt.Columns("ID").AutoIncrementSeed = 1
dt.Columns("ID").ReadOnly = True

dt.Columns.Add("Name", GetType(String))

Dim dr = dt.NewRow()
dr("Name") = "John"
dt.Rows.Add(dr)

dr = dt.NewRow()

dr("Name") = "Dan"
dt.Rows.Add(dr)

DataGridView1.DataSource = dt

C#

DataTable dt = new DataTable();

dt.Columns.Add("ID", typeof(int));
dt.PrimaryKey = new DataColumn[] { dt.Columns["ID"] };
dt.Columns["ID"].AutoIncrement = true;
dt.Columns["ID"].AutoIncrementSeed = 1;
dt.Columns["ID"].ReadOnly = true;

dt.Columns.Add("Name", typeof(string));

dynamic dr = dt.NewRow();
dr("Name") = "John";
dt.Rows.Add(dr);

dr = dt.NewRow();
dr("Name") = "Dan";
dt.Rows.Add(dr);

DataGridView1.DataSource = dt;

c# font Italic label example

C# > Drawing > Font > Italic

Italic indicates when Font is italic.

Example:

label1.Font = new System.Drawing.Font(label1.Font, FontStyle.Italic);

Tuesday, December 10, 2013

C# Create new bitmap example

C# > Drawing > Bitmap

Bitmap contains pixel data for a graphics image. You can save bitmap to GDI+ file formats: BMP, GIF, EXIF, JPG, PNG and TIFF.

Example
Create new bitmap in runtime

Bitmap bmp = new System.Drawing.Bitmap(200, 200);

for (int x = 0; x < bmp.Height; ++x)
   for (int y = 0; y < bmp.Width; ++y)
     bmp.SetPixel(x, y, Color.Coral );
for (int x = 0; x < bmp.Height / 2; ++x)
   for (int y = 0; y < bmp.Width / 2; ++y)
     bmp.SetPixel(x, y, Color.Blue );
pictureBox1.Image = bmp;