C#编程之文件IO
之前我们用c++处理过文件IO管控,这里我们讲一下用c#对文件流的管控。
同样,我们做一个例程,实现文件crc计算,通过打开按钮选择文件,或者通过拖拽方式选择文件。
步骤如下:
- UI布局
- XAML:
1 <Window x:Class="FileSample.MainWindow" 2 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4 Title="MainWindow" Height="350" Width="525"> 5 <Grid> 6 <Button Name="myButton" Content=" Open File " Margin="10,10,0,0" VerticalAlignment="Top" HorizontalAlignment="Left" 7 Click="open_Click"/> 8 <TextBox Name="UserInput" Height="100" Margin="10,50,0,0" VerticalAlignment="Top" HorizontalAlignment="Stretch" 9 AllowDrop="True" PreviewDrop="TextBox_PreviewDrop" PreviewDragOver="TextBox_PreviewDragOver" IsReadOnly="True"/> 10 </Grid> 11 </Window>
- 因为我们需要用到IO数据流,所以需要使用IO类: 1 using System.IO;
- CS:
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 using System.Threading.Tasks; 6 using System.Windows; 7 using System.Windows.Controls; 8 using System.Windows.Data; 9 using System.Windows.Documents; 10 using System.Windows.Input; 11 using System.Windows.Media; 12 using System.Windows.Media.Imaging; 13 using System.Windows.Navigation; 14 using System.Windows.Shapes; 15 using System.IO; 16 17 namespace FileSample 18 { 19 /// <summary> 20 /// Interaction logic for MainWindow.xaml 21 /// </summary> 22 public partial class MainWindow : Window 23 { 24 UInt16 [] crc_table=new UInt16[256]{ 25 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, 26 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef, 27 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6, 28 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de, 29 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485, 30 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d, 31 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4, 32 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc, 33 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823, 34 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b, 35 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12, 36 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a, 37 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41, 38 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49, 39 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70, 40 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78, 41 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f, 42 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067, 43 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e, 44 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256, 45 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d, 46 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405, 47 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c, 48 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634, 49 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab, 50 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3, 51 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a, 52 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92, 53 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9, 54 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1, 55 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8, 56 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0}; 57 public MainWindow() 58 { 59 InitializeComponent(); 60 } 61 public UInt16 crc_16(UInt16 crc, byte data) 62 { 63 byte da; 64 65 da = (byte)(crc / 256); 66 crc <<= 8; //crc=crc*256 67 crc ^= crc_table[da ^ data]; 68 return crc; 69 } 70 private void open_Click(object sender, RoutedEventArgs e) 71 { 72 System.Windows.Forms.OpenFileDialog openfile = new System.Windows.Forms.OpenFileDialog(); 73 UInt16 crc; 74 openfile.InitialDirectory = "D:\\"; 75 openfile.Filter = "txt files |*.txt|All files |*.*"; 76 openfile.FilterIndex = 1; 77 openfile.RestoreDirectory = true; 78 if(openfile.ShowDialog()==System.Windows.Forms.DialogResult.OK) 79 { 80 UserInput.Text = openfile.FileName + "\r\n"; 81 StreamReader sr = new System.IO.StreamReader(openfile.FileName, Encoding.Default); 82 crc = 0xffff; 83 while(sr.Peek() > 0) 84 { 85 //UserInput.Text += (char)sr.Read(); 86 crc = crc_16(crc, (byte)sr.Read()); 87 } 88 UserInput.Text += "crc=" + Convert.ToString(crc) + "\r\n"; 89 } 90 } 91 92 private void TextBox_PreviewDrop(object sender, DragEventArgs e) 93 { 94 UInt16 crc; 95 //get files counter 96 Array fileArray = (System.Array)e.Data.GetData(DataFormats.FileDrop); 97 UserInput.Text = ""; 98 string filePath; 99 for (int i=0; i < fileArray.Length; i++) 100 { 101 filePath = ((System.Array)e.Data.GetData(DataFormats.FileDrop)).GetValue(i).ToString(); 102 UserInput.Text += filePath + "\r\n"; 103 StreamReader sr=new System.IO.StreamReader(filePath,Encoding.Default); 104 crc = 0xffff; 105 while(sr.Peek()>0) 106 { 107 crc = crc_16(crc, (byte)sr.Read()); 108 } 109 UserInput.Text += "crc=" + Convert.ToString(crc) + "\r\n"; 110 } 111 } 112 113 private void TextBox_PreviewDragOver(object sender, DragEventArgs e) 114 { 115 if (e.Data.GetDataPresent(DataFormats.FileDrop)) 116 { 117 e.Effects = DragDropEffects.Link; 118 e.Handled = true; 119 } 120 else 121 e.Effects = DragDropEffects.None; 122 } 123 } 124 }
- 编译运行。
End.