C#练习.

练习

任务

1、绘制一圆，其圆心坐标为(150,100)，半径为40。要求用蓝色且宽度为1画笔。
2、绘制一圆，其圆心坐标为(200,200)，半径为100。要求用红色画实心画刷(SolidBrush类的一个实例)。
3、利用颜色对话框将窗体的背景颜色修改为颜色对话框所选的颜色。
4、利用字体对话框将窗体的上的文本框textBox1的字体修改为字体对话框所选字体。
5、利用保存文件对话框，利用FileStream和StreamWriter将1-100内的100个数字按顺序写入到保存文件对话框所指定的文件中，每个数字写一行。
6、利用打开文件对话框，利用FileStream和StreamReader读取所选文件的内容(如第5题中的文件)，把文件的内容显示到窗体的ListBox1中。
7、基础点绘制。

代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
namespace FuXiText
{
    public partial class Form1 : Form
    {
        int i = 0;
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Graphics g = CreateGraphics();
            Pen p1 = new Pen(Color.Blue, 1);
            Point point = new Point(150, 100);
            Size size = new Size(40, 40);
           Rectangle r1=new Rectangle(point, size);
            g.DrawEllipse(p1, r1);
            g.Dispose();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Graphics g = CreateGraphics();
            Brush brush = new SolidBrush(Color.Red);
            Point p = new Point(200, 200);
            Size size = new Size(100, 100);
            Rectangle rec = new Rectangle(p, size);
            g.FillEllipse(brush, rec);
            g.Dispose();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            ColorDialog cd=new ColorDialog();
            DialogResult dr=cd.ShowDialog();
            if (dr == DialogResult.OK)
            {
                MessageBox.Show("设置成功！！！");
                BackColor = cd.Color;

            }

        }

        private void button4_Click(object sender, EventArgs e)
        {
          DialogResult  cd=MessageBox.Show("危险！！！","确定要刷新吗？",MessageBoxButtons.OKCancel);
            if (cd == DialogResult.OK)
            {
                this.Controls.Clear();//刷新控件，控件会消失，可以重新调用函数重新渲染
                MessageBox.Show("憨批");
                MessageBox.Show("拜拜了您嘞");
            }
            else {
                MessageBox.Show("可惜~~~");
                using (Graphics g = this.CreateGraphics())
                {
                    g.Clear(this.BackColor);
                }//GDI+画图内容刷新
                BackColor = Color.White;
            }
           
           
        }

        private void button5_Click(object sender, EventArgs e)
        {
            FontDialog fd= new FontDialog();
            DialogResult dr=fd.ShowDialog();
            if (dr == DialogResult.OK)
            {
                MessageBox.Show("设置成功！！！");
                textBox1.Font= fd.Font;
                textBox1.Text = "骗你的~~~";
            }
        }

        private void button6_Click(object sender, EventArgs e)
        {
            SaveFileDialog sfd= new SaveFileDialog();
            sfd.Filter = "文本文件(txt)|*.txt";
            sfd.Title = "保存文件";
            DialogResult dr=sfd.ShowDialog();
            if (dr == DialogResult.OK)
            { //创建文本流
                FileStream fs=new FileStream(sfd.FileName, FileMode.OpenOrCreate);
                //创建读写器
                StreamWriter sw=new StreamWriter(fs);
             
                for (int i = 1; i <= 100; i++)
                { 
                    //执行读写操作
                    sw.WriteLine(i.ToString());
                    
                }
                textBox1.Text = "存储完毕~~~";
                sw.Close();
                sfd.Dispose();

            }

        }

        private void button7_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd= new OpenFileDialog();
            ofd.Filter = "文本txt|*.txt";
            ofd.Title = "打开文件";
            DialogResult dr= ofd.ShowDialog();
            if (dr == DialogResult.OK)
            {
                FileStream fs = new FileStream(ofd.FileName, FileMode.OpenOrCreate);
                StreamReader sr = new StreamReader(fs);
                string line;
                while ((line=sr.ReadLine())!=null)
                { 
                    listBox1.Items.Add(line);
                }
                sr.Close();
                ofd.Dispose();
            }
            else {
                MessageBox.Show("打开失败");
            }
            textBox1.Text = "读取成功~~~";
            
        }

        private void button8_Click(object sender, EventArgs e)
        {
           
        }

        private void Form1_MouseDown(object sender, MouseEventArgs e)
        {
            Brush brush = new SolidBrush(Color.Pink);
            Graphics g=CreateGraphics();
            if (e.Button == MouseButtons.Left)
            {
                g.FillEllipse(brush, e.X, e.Y, 10, 10);
                textBox1.Text = ++i + "个点";
            }
           
            
        }
    }
}