Question

我的zip文件替换现有文件时出现问题。我已经看过这里的其他例子了，我似乎无法弄明白...... 我有一个loop，它将提取的文件的一些统计信息写入文本框。我认为就是这一行：

if (!System.IO.File.Exists(fileUnzipFullName))

我的代码：

    public void UnzipFileNew()
    {
        richTextBox1.AppendText("\r\n" + "EXTRACTING!");

        String rootpath = Environment.CurrentDirectory;
        //This stores the path where the file should be unzipped to,
        //including any subfolders that the file was originally in.
        string fileUnzipFullPath;

        //This is the full name of the destination file including
        //the path
        string fileUnzipFullName;

        //Opens the zip file up to be read
        using (ZipArchive archive = ZipFile.OpenRead(@"update.zip"))
        {
            //Loops through each file in the zip file
            foreach (ZipArchiveEntry file in archive.Entries)
            {

                //Outputs file information to the Textbox
                richTextBox1.AppendText("\r\n");
                richTextBox1.AppendText("File Name: "+ file.Name);
                richTextBox1.AppendText("\r\n");
                richTextBox1.AppendText("File Size: bytes "+ file.Length);
                richTextBox1.AppendText("\r\n");
                richTextBox1.AppendText("Compression Ratio: "+ ((double)file.CompressedLength / file.Length).ToString("0.0%"));
                richTextBox1.AppendText("\r\n");

                //Identifies the destination file name and path
                fileUnzipFullName = Path.Combine(rootpath, file.FullName); //fileUnzipFullName = Path.Combine(@"Example\", file.FullName);

                //Extracts 
                if (!System.IO.File.Exists(fileUnzipFullName))
                {

                    fileUnzipFullPath = Path.GetDirectoryName(fileUnzipFullName);

                    //Creates the directory if it doesn't exist
                    Directory.CreateDirectory(fileUnzipFullPath);

                    //Extracts the file to (potentially new) path
                    file.ExtractToFile(fileUnzipFullName);
                }

            }
        }
    }

Answer 1

如果文件已存在，

if (!System.IO.File.Exists(fileUnzipFullName))确实会阻止您尝试提取文件。因此，您需要将其删除或根据您的使用情况进行更改。

此外，如果文件已经存在，ExtractToFile方法将抛出IOException。幸运的是，MSDN显示有一个带有布尔标志的重载用于覆盖：

public static void ExtractToFile(
    this ZipArchiveEntry source,
    string destinationFileName,
    bool overwrite
)

所以而不是

file.ExtractToFile(fileUnzipFullName);

使用

file.ExtractToFile(fileUnzipFullName, true);

使用你的代码，这将不加区别地用从zip中提取的文件覆盖所有文件：

//Extracts 
//if (!System.IO.File.Exists(fileUnzipFullName))
//{
    fileUnzipFullPath = Path.GetDirectoryName(fileUnzipFullName);

    //Creates the directory if it doesn't exist
    Directory.CreateDirectory(fileUnzipFullPath);

    //Extracts the file to (potentially new) path
    file.ExtractToFile(fileUnzipFullName, true);
//}

解压缩不替换文件

1 个答案: