Application of C#chart Chart

In the chart, the x-axis represents the category, and the y-axis represents the values (like the class and their attributes)

This is the data in the database, below we choose the first 5 cars, show their names in the chart, fuel consumption, power, price

To create a class for querying data

 class Carda {public List < cardata> select () {List < cardata > list= null; SqlConnection conn = new SqlConnection ("server=.;            Database=mydb;user=sa;pwd=123 "); Conn.            Open (); SqlCommand cmd = conn.            CreateCommand ();            Cmd.commandtext = "Select top 5* from car"; SqlDataReader dr= cmd.            ExecuteReader (); if (Dr.                HasRows) {list = new list<cardata> (); while (Dr.                Read ()) {Cardata data = new Cardata ();                data = new Cardata (); Data. Name = dr["Name"].                ToString (); Data.                Oil= (decimal) dr["oil"; Data. powers=dr["Powers"].                ToString (); Data.                Price= (decimal) dr["Price"; List.                ADD (data);            }} return list; Cmd.            Dispose (); Conn.        Close (); }    }

Class Cardata    {        private string _name;        public string Name        {            get {return _name;}            set {_name = value;}        }        private decimal _oil;        Public decimal Oil        {            get {return _oil;}            set {_oil = value;}        }        private string  _powers;        public string  Powers        {            get {return _powers;}            set {_powers = value;}        }        private decimal _price;        Public decimal price        {            get {return _price;}            set {_price = value;}        }    }

When a form is loaded, the data source is bound to the chart, note that the binding is in a single column, indicating that the x and Y axes of each row correspond to the property name of the data source (that is, the property name of the object in the generic collection). Note: The specified must be a property name and cannot be a field name, which also requires that the data source object's fields must be encapsulated and must have attributes.

This shows the encapsulation features of C # programming, we give the chart tool a data source, let it help us visualize the data, we do not care about how it is implemented, we only tell it needs to display the data, the rest of it to the chart tool.

private void Form1_Load (object sender, EventArgs e)        {            list<cardata> List = new Carda (). Select ();            if (list! = null)            {                Chart1. DataSource = list;                Chart1. series["Series1"]. xvaluemember= "name";                Chart1. series["Series1"]. Yvaluemembers = "oil";            }        }

Run results

In the Series property, you can set the display name for each column and add a new column

private void Form1_Load (object sender, EventArgs e)        {            list<cardata> List = new Carda (). Select ();            if (list! = null)            {                Chart1. DataSource = list;                Chart1. series["fuel consumption"]. xvaluemember= "name";                Chart1. series["fuel consumption"]. Yvaluemembers = "oil";                Chart1. series["Power"]. Xvaluemember = "name";                Chart1. series["Power"]. Yvaluemembers = "Powers";                Chart1. series["Price"]. Xvaluemember = "name";                Chart1. series["Price"]. Yvaluemembers = "Price";            }        }

Application of C#chart Chart