文件流FileStream案例二
先上代码
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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 文件流FileStream案例二 { public partial class Form1 : Form { public Form1() { InitializeComponent(); } int TypeW = 0; /// <summary> /// 选定某个文件夹 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button1_Click(object sender, EventArgs e) { FolderBrowserDialog openfolder = new FolderBrowserDialog(); if (openfolder.ShowDialog() == DialogResult.OK) { textBox1.Text = Convert.ToString(openfolder.SelectedPath); TypeW = 1; } } private void button2_Click(object sender, EventArgs e) { OpenFileDialog openfile = new OpenFileDialog(); openfile.Filter = "文本文件|*.txt"; if (openfile.ShowDialog() == DialogResult.OK) { FileStream openfilestream = new FileStream(openfile.FileName, FileMode.Open, FileAccess.Read); StreamReader sr = new StreamReader(openfilestream, Encoding.Default); richTextBox1.Text = sr.ReadToEnd(); textBox2.Text = Convert.ToString(openfile.FileName); sr.Close(); openfilestream.Close(); TypeW = 2; } } private void button3_Click(object sender, EventArgs e) { if (richTextBox1.Text == string.Empty) { MessageBox.Show("编辑文本文件内容禁止为空", "提示信息"); return; } else { if (TypeW == 1) { FileStream fs = new FileStream(textBox1.Text + @"\\anshenwoaini.txt", FileMode.Create, FileAccess.ReadWrite); StreamWriter sw = new StreamWriter(fs, Encoding.Default); sw.Write(richTextBox1.Text); TypeW = 0; MessageBox.Show("已经成功地将文本文件写入"); sw.Close(); fs.Close(); } else if (TypeW == 2) { FileStream fs = new FileStream(textBox2.Text, FileMode.OpenOrCreate, FileAccess.ReadWrite); StreamWriter sw = new StreamWriter(fs, Encoding.Default); sw.Write(richTextBox1.Text); MessageBox.Show("yijingchenggong"); sw.Close(); fs.Close(); } } } } }
首先,选定文件夹是为了选择新文本文件保存路径。
这是提示用户选择文件
SelectedPath是FolderBrowserDialog类的一个方法,获取或设置用户选定的路径。
选定文件是打开已存在的文件进行继续编辑。
在一般情况下,写不写FileStream都可以进行,但是
所以
不管是读还是写,StreamReader和StreamWriter使用前用文件流FileStream来读,防止数据丢失。
最后要根据先用后关的原则,跟栈一样,先进后出地关闭线程资源,顺序不能错。
保存文件,要根据上面两种情况分类,写法类似。