With a picturebox mousemove events, when they draw a straight line with the mouse drawing lines, with the Clear words, before all the Clear, how to raise to achieve like Windows sketchpad draw a straight line???????
This bothers me a lot of days, few scores in all

CodePudding user response:

The complete code: https://download.csdn.net/download/caozhy/12082528

Problem solving, please stick to points

 using System; 
using System.Collections.Generic; 
Using System.Com ponentModel; 
Using System. The Data; 
Using System. Drawing; 
using System.Linq; 
Using System. The Text; 
Using System. Windows. Forms; 

The namespace T395559890 
{
Public partial class Form1: Form 
{
Public _click () 
{
InitializeComponent(); 
Enclosing DoubleBuffered=true; 
} 

Private List Lines=new List (a); 

Private Point? The pre. 

Private void Form1_Paint (object sender, PaintEventArgs e) 
{
The foreach (var item in lines) 
{
Um participant raphics. DrawLine (Pens. Black, item. The Item1, item. The Item2); 
} 
} 

Private void Form1_MouseMove (object sender, MouseEventArgs e) 
{
If (e.B utton==System. Windows. Forms. MouseButtons. Left) 
{
If (pre. HasValue) 
{
Lines. The Add (new Tuple (pre) Value, new Point (e.X, e.Y))); 
The Refresh (); 
} 
The pre=new Point (e.X, e.Y); 
} 
The else 
{
If (pre. HasValue) 
{
Lines. The Add (new Tuple (pre) Value, new Point (e.X, e.Y))); 
The Refresh (); 
} 
The pre=null; 
} 
} 
} 
}