// here is the full code.
// I would expect the btnLine_Click() method to start the timer (which it does) and then
// accept "angle" from the "public float myangle" getter but it does not. So it only draws // one 30 degree hard coded line. I desire the line to be incremented around in 10
// degree steps sort of like the second hands of a clock.
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Drawing.Imaging;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using System.IO;
using System.Text;
namespace DrawingShapesApp
{
public class Form1 : Form
{
private Bitmap DrawingArea;
private Pen myPen;
private System.Windows.Forms.Timer timer1;
private System.ComponentModel.IContainer components;
private Button btnLine;
float angle;
public float x1=300; // 1st point pair
public float y1=500;
public float x2=500; // 2nd point pair
public float y2=300;
public double angleX = 30; // 30 degrees
public double Xdist;
public double sqrt;
public Form1()
{
InitializeComponent();
}
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
private void InitializeComponent()
{
this.ClientSize = new System.Drawing.Size(800, 650);
this.Text="line5";
this.components = new System.ComponentModel.Container();
this.timer1 = new System.Windows.Forms.Timer(this.components);
this.SuspendLayout();
btnLine = new Button();
this.btnLine.Location = new System.Drawing.Point(8, 88);
this.btnLine.Name = "btnLine";
this.btnLine.Size = new System.Drawing.Size(40, 40);
this.btnLine.TabIndex = 1;
this.btnLine.Text = "Step";
this.Controls.Add(this.btnLine);
// Load this "frmGraphics_Load" at load time
this.Load += new System.EventHandler(this.frmGraphics_Load);
this.Closed += new System.EventHandler(this.frmGraphics_Closed);
this.Paint += new System.Windows.Forms.PaintEventHandler(this.frmGraphics_Paint);
this.ResumeLayout(false);
myPen = new Pen(Color.Blue);
this.btnLine.Click += new System.EventHandler(this.btnLine_Click);
}
static void Main()
{
Application.Run(new Form1());
}
private void frmGraphics_Load(object sender, System.EventArgs e) // a clickable event
{
Console.WriteLine("First...load this: frmGraphics_Load");
// create a new bitmap...defining the bitmap the same size as the form
DrawingArea = new Bitmap(
this.ClientRectangle.Width,
this.ClientRectangle.Height,
System.Drawing.Imaging.PixelFormat.Format24bppRgb);
InitializeDrawingArea();
}
// copy from bitmap to the form
private void InitializeDrawingArea()
{
Graphics oGraphics; // oGraphics is the form
oGraphics = Graphics.FromImage(DrawingArea); // copy bitmap to form
myPen.Color = Color.AliceBlue;
for ( int x = 0; x 359)
angle=0;
Console.WriteLine("**timer1 angle= {0}", angle);
float myangle = angle;
if(angle == 90)
this.timer1.Enabled = false;
Invalidate();
}
public float myangle
{
set { angle = value; }
get { return angle; }
}
private void btnLine_Click(object sender, System.EventArgs e)
{
this.timer1.Enabled = true;
this.timer1.Tick += new System.EventHandler(this.timer1_Tick);
// timer now active...why does it not take the angle from timer1_Tick() ?
// I need to increment the drawline by 10 degrees like the hand of a clock
Console.WriteLine("in btnLine_Click");
// draws a hardcoded line but cannot get "angle" from timer1_Tick()
Graphics oGraphics;
oGraphics = Graphics.FromImage(DrawingArea); // copy from bitmap to form
Pen Grn = new Pen(Color.Green, 2);
Pen penBlue = new Pen(Color.Blue, 1);
Rectangle rect = new Rectangle(100, 100, 400, 400); // draw circle
oGraphics.DrawEllipse( penBlue, rect );
oGraphics.DrawLine(Grn, 300, 300, 500, 300); // draw horiz. line
PointF p1 = new PointF(x1, y1);
PointF p2 = new PointF(x2, y2);
double Xdist = Math.Abs(p2.X - p1.X);
Console.WriteLine("Xdist= {0}", Xdist);
double angle30 = Math.Cos(DegreeToRadian(30)); // need myangle in place of 30
Console.WriteLine("angle30= {0}", angle30);
double side_c = Math.Tan(DegreeToRadian(angleX)) * Xdist;
Console.WriteLine("side_c= {0}", side_c);
sqrt = (Xdist*Xdist + side_c*side_c);
double side_a = Math.Sqrt(sqrt);
Console.WriteLine("side_a= {0}", side_a);
// this draws a
oGraphics.DrawLine(Grn, 300, 300, 300+(float)173.21, 300-100); // intersects circle
oGraphics.DrawLine(Grn, 300+(float)173.21, 300, 300+(float)173.21, 300-100); // draw vert. line
oGraphics.Dispose(); // clean up graphics object
this.Invalidate(); // force form to redraw itself
}
private double DegreeToRadian(double angle)
{
return Math.PI * angle / 180.0;
}
private double RadianToDegree(double angle)
{
return angle * (180.0 / Math.PI);
}
public void timer_stop()
{
Console.WriteLine("Halting timer!");
this.timer1.Enabled = false; // halts operation
}
}
}
答案 0 :(得分：5)
也许只是你的计时器可以＆gt; 359其中Total被重置为0.可能是这种情况吗？
在处理某些变量时，您似乎也在尝试使用属性。
在整体中包含一个集合，它可以帮助其他程序员准确理解你在做什么。
public float Total { get { return angle; } set { angle = value; } }
然后改变
float Total = angle;
到
Total = angle;
你最初拥有的是你已经声明了一个名为Total的局部变量，一旦你达到了该函数的范围，该值就消失了。为了保持您想要设置属性Total的值，使用angle。
此外，您可能希望更详细地了解您的问题。您需要发布更多相关代码，例如Invalidate（）内部的代码。我编辑了你的问题，当发布代码示例时，使用小二进制0和1来分离实际内容中的代码。它可以帮助那些想要帮助你的人:)。
我几乎诚实地认为你的计时器得到它的值，因为满足条件（如果条件）并且角度重置为0.否则，你需要发布Invalidate（）以查看是否改变了角度的值
答案 1 :(得分：2)
如果您的计时器经常运行，也许您已经混淆了计算间隔，那么它会经常运行以至于它会快速通过359然后设置为0，然后循环将再次开始。如上所述，设置断点。将它放在Invalidate语句上，然后将鼠标悬停在Angle上，看看它的值是什么。
同样float Total=angle;没有完成任何事情，因为Total在此上下文中是一个局部变量，永远不会被使用。
答案 2 :(得分：1)
由于这里的原始海报没有回答可能出错的地方。
希望得到这个帮助。