private void 颜色ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //对话框结果类型定义变量接受颜色
            DialogResult dr = colorDialog1.ShowDialog();
            //对话框结果确定键
            if (dr == DialogResult.OK)
            {
                //改变所有文字前景色
                textBox1.ForeColor = colorDialog1.Color;
            }           
        }

 private void 字体ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //对话框结果类型定义变量接受字体
            DialogResult dr = fontDialog1.ShowDialog();
            //对话框结果确定键
            if (dr == DialogResult.OK)
            {
                //改变所有文字前景色、字体
                textBox1.Font = fontDialog1.Font;
                textBox1.ForeColor = colorDialog1.Color;
            }
        }

private void 打开OToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //对话框打开文件类定义
            DialogResult dr = openFileDialog1.ShowDialog();
            //确定判断
            if (dr==DialogResult.OK)
            {
                //流对象实例化                          // 打开文件地址           应用编码类型
                StreamReader sr = new StreamReader(openFileDialog1.FileName,Encoding.Default);
                //文件从头读到尾
                textBox1.Text = sr.ReadToEnd();
            }
        }

//默认保存路径
        string path = "";
        private void 保存SToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (path == null)
            {
                //对话框保存文件类
                DialogResult dr = saveFileDialog1.ShowDialog();
                //确定判断
                if (dr == DialogResult.OK)
                {
                    //写入流定义
                    StreamWriter sw = new StreamWriter(saveFileDialog1.FileName);
                    //写入文件
                    sw.Write(textBox1.Text);
                    //调方法
                    sw.Flush();
                    //关流
                    sw.Close();
                    path = saveFileDialog1.FileName;
                }
            }
            else {
                //写入流定义
                StreamWriter sw = new StreamWriter(saveFileDialog1.FileName);
                //写入文件
                sw.Write(textBox1.Text);
                //调方法
                sw.Flush();
                //关流
                sw.Close();
                path = saveFileDialog1.FileName;
            }
        }