c# winform 路徑選擇和文件讀寫

//讀文件
        private void readBtn_Click(object sender, EventArgs e)
        {
            try 
            {
                if (pathTxt.Text == "")
                {
                    MessageBox.Show("請輸入文件地址");
                    return;
                }
                readTxt.Text = File.ReadAllText(pathTxt.Text, Encoding.Default);//不需要對地址中的"\"進行轉義
            }
            catch (Exception ex)
            {
                MessageBox.Show("文件地址錯誤");
            }
           
            
        }
        //寫文件
        private void writeBtn_Click(object sender, EventArgs e)
        {
            try
            {
                if (pathTxt.Text == "")
                {
                    MessageBox.Show("請輸入文件地址");
                    return;
                }
                File.WriteAllText(pathTxt.Text, writeTxt.Text);
                MessageBox.Show("success");
            }
            catch (Exception ex)
            {
                MessageBox.Show("文件地址錯誤");
            }
        }
        //讀取文件夾路徑
        private void folderBtn_Click(object sender, EventArgs e)
        {
            if (folderBrowserDialog1.ShowDialog() == DialogResult.OK)
            {
                folderTxt.Text = folderBrowserDialog1.SelectedPath;
            }
        }
        //讀取文件路徑
        private void fileBtn_Click(object sender, EventArgs e)
        {
            
            OpenFileDialog op = new OpenFileDialog();
            op.Filter = "Text files (*.txt)|*.txt|All Files(*.*)|*.*";
            if (op.ShowDialog() == DialogResult.OK)
            {
                pathTxt.Text = op.FileName;
            }
        }