C# 文件Copy

文件Copy有以下幾種方法：

1.Copy

string sourceFile = @"c:\temp\New Text Document.txt"; 
string destinationFile = @"c:\temp\test.txt"; 
bool isrewrite=true; // true=覆蓋已存在的同名文件,false則反之
System.IO.File.Copy(sourcePath, targetPath, isrewrite); 

 

2.CopyTo

string sourceFile = @"c:\temp\New Text Document.txt"; 
string destinationFile = @"c:\temp\test.txt"; 
FileInfo file = new FileInfo(sourceFile); 
if (file.Exists) 
{ 
    // true is overwrite 
    file.CopyTo(destinationFile, true); 
} 

 

3.使用文件流讀寫來實現Copy

#region 拷貝操作
private void button3_Click(object sender, EventArgs e)
{
    OpenFileDialog ofd = new OpenFileDialog();
    DialogResult res = ofd.ShowDialog();
    if (res == DialogResult.OK) 
    {
        if (!string.IsNullOrEmpty(ofd.FileName))
        {
            //1.創建讀入文件流對象
            FileStream streamRead = new FileStream(ofd.FileName, FileMode.Open);
            //2.創建1個字節數組，用於接收文件流對象讀操作文件值
            byte[] data = new byte[1024 * 1024];//1M
            int length = 0;
            SaveFileDialog sfd = new SaveFileDialog();
            DialogResult sres = sfd.ShowDialog();
            if (sres == DialogResult.OK)
            {
                if (!string.IsNullOrEmpty(ofd.FileName))
                {
                    FileStream streamWrite = new FileStream(sfd.FileName, FileMode.Create);
                    do
                    {
                        //3.文件流讀方法的參數1.data-文件流讀出數據要存的地方，2. 0--從什么位置讀，3. data.Length--1次讀多少字節數據
                        //3.1 Read方法的返回值是一個int類型的，代表他真實讀取 字節數據的長度，
                        length = streamRead.Read(data, 0, data.Length);//大文件讀入時候，我們定義字節長度的可能會有限，如果文件超大，要接收文件流對象的Read()方法，會返回讀入的實際長度
                        //加密 和解密
                        for (int i = 0; i < length; i++) 
                        {
                             data[i] = (byte)(255 - data[i]);
                        }
                            streamWrite.Write(data, 0, length);
                    } while (length == data.Length); //如果實際寫入長度等於我們設定的長度，有兩種情況1.文件正好是我們設定的長度2.文件超大只上傳了截取的一部分
                }
            }
        }
    }
}
#endregion   

 

本文引自：http://www.cnblogs.com/WarBlog/p/5826778.html