打开现有的文件，追加一行

我想打开一个文本文件，向它追加一行，然后closures它。

Answer 1

您可以使用File.AppendAllText ：

 File.AppendAllText(@"c:\path\file.txt", "text content" + Environment.NewLine); 

Answer 2

 using (StreamWriter w = File.AppendText("myFile.txt")) { w.WriteLine("hello"); } 

Answer 3

select一个！ 但是第一个很简单。 最后可能用于文件操作：

 //Method 1 (I like this) File.AppendAllLines( "FileAppendAllLines.txt", new string[] { "line1", "line2", "line3" }); //Method 2 File.AppendAllText( "FileAppendAllText.txt", "line1" + Environment.NewLine + "line2" + Environment.NewLine + "line3" + Environment.NewLine); //Method 3 using (StreamWriter stream = File.AppendText("FileAppendText.txt")) { stream.WriteLine("line1"); stream.WriteLine("line2"); stream.WriteLine("line3"); } //Method 4 using (StreamWriter stream = new StreamWriter("StreamWriter.txt", true)) { stream.WriteLine("line1"); stream.WriteLine("line2"); stream.WriteLine("line3"); } //Method 5 using (StreamWriter stream = new FileInfo("FileInfo.txt").AppendText()) { stream.WriteLine("line1"); stream.WriteLine("line2"); stream.WriteLine("line3"); } 

Answer 4

可能要检查TextWriter类。

 //Open File TextWriter tw = new StreamWriter("file.txt"); //Write to file tw.WriteLine("test info"); //Close File tw.Close(); 

Answer 5

或者你可以使用File.AppendAllLines(string, IEnumerable<string>)

 File.AppendAllLines(@"C:\Path\file.txt", new[] { "my text content" }); 

Answer 6

File.AppendText将做到这一点：

 using (StreamWriter w = File.AppendText("textFile.txt")) { w.WriteLine ("-------HURRAY----------"); w.Flush(); } 

Answer 7

//我们可以用

公共StreamWriter（stringpath，布尔附加）;

同时打开文件

StreamWriter SW = new StreamWriter（Path，true）;

第一个参数是保存文件完整path的string第二个参数是Append Mode，在这种情况下，它被设置为true string Path =“C：\ MyFolder \ Notes.txt”

写在文件上可以完成

SW.Write（串）

要么

SW..WriteLine（串）

SW.WriteLine（“Some Text”）;

SW.Flush（）;

SW.Close（）;

示例代码

 private void WriteAndAppend() { string Path = Application.StartupPath + "\\notes.txt"; FileInfo fi = new FileInfo(Path); StreamWriter SW; StreamReader SR; if (fi.Exists) { SR = new StreamReader(Path); string Line = ""; while (!SR.EndOfStream) // Till the last line { Line = SR.ReadLine(); } SR.Close(); int x = 0; if (Line.Trim().Length <= 0) { x = 0; } else { x = Convert.ToInt32(Line.Substring(0, Line.IndexOf('.'))); } x++; SW = new StreamWriter(Path, true); SW.WriteLine("-----"+string.Format("{0:dd-MMM-yyyy hh:mm:ss tt}", DateTime.Now)); SW.WriteLine(x.ToString() + "." + textBox1.Text); } else { SW = new StreamWriter(Path); SW.WriteLine("-----" + string.Format("{0:dd-MMM-yyyy hh:mm:ss tt}", DateTime.Now)); SW.WriteLine("1." + textBox1.Text); } SW.Flush(); SW.Close(); } 

Answer 8

 //display sample reg form in notepad.txt using (StreamWriter stream = new FileInfo("D:\\tt.txt").AppendText())//ur file location//.AppendText()) { stream.WriteLine("Name :" + textBox1.Text);//display textbox data in notepad stream.WriteLine("DOB : " + dateTimePicker1.Text);//display datepicker data in notepad stream.WriteLine("DEP:" + comboBox1.SelectedItem.ToString()); stream.WriteLine("EXM :" + listBox1.SelectedItem.ToString()); } 

Answer 9

技术上最好的方法可能是这里：

 private static async Task AppendLineToFile([NotNull] string path, string line) { if (string.IsNullOrWhiteSpace(path)) throw new ArgumentOutOfRangeException(nameof(path), path, "Was null or whitepsace."); if (!File.Exists(path)) throw new FileNotFoundException("File not found.", nameof(path)); using (var file = File.Open(path, FileMode.Append, FileAccess.Write)) using (var writer = new StreamWriter(file)) { await writer.WriteLineAsync(line); await writer.FlushAsync(); } }