需要恢复在Catch块之后尝试

Question

从VB6时代开始,当我通过系统上的目录递归时,我能够以相对适当的方式使用"on next error next".如果我的"foreach"循环遇到Permission Denied或Access Denied错误,我所要做的就是调用"resume next"语句.

然而,在C#中,这不存在,我理解为什么.然而,令人难以理解的是在C#中弄清楚这是如何实现的.

我试图通过我的硬盘上的目录递归并填充TreeView控件.

private void PopulateTree(string dir, TreeNode node)
    {
        try
        {
            // get the information of the directory
            DirectoryInfo directory = new DirectoryInfo(dir);

            // loop through each subdirectory
            foreach (DirectoryInfo d in directory.GetDirectories("*", SearchOption.AllDirectories))
            {
                // create a new node
                TreeNode t = new TreeNode(d.Name);
                // populate the new node recursively
                PopulateTree(d.FullName, t);
                node.Nodes.Add(t); // add the node to the "master" node
            }

            // lastly, loop through each file in the directory, and add these as nodes
            foreach (FileInfo f in directory.GetFiles())
            {
                // create a new node
                TreeNode t = new TreeNode(f.Name);
                // add it to the "master"
                node.Nodes.Add(t);
            }
        }
        catch (System.Exception e)
        {
            MessageBox.Show(e.Message, "Error Loading Directories", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
        }

    }

代码预计会起作用.但是,当它到达"C:\\Documents and Settings"Windows 7计算机上的文件夹时,catch块会捕获"拒绝访问"错误(我期望).我想要做的是继续使用系列中的下一个文件夹.

所以问题是,我怎样才能在C#中实现这一目标？

我的研究显示了使用TRY ... CATCH块的常见观点,但它并没有告诉我如何做一些如上所述我想做的事情.

注意:我也尝试修改代码以检查属性如下,但它也失败了.

private void PopulateTree(string dir, TreeNode node)
    {
        try
        {
            // get the information of the directory
            DirectoryInfo directory = new DirectoryInfo(dir);

            if (directory.Attributes == FileAttributes.ReparsePoint || directory.Attributes == FileAttributes.System)
            {
                Console.Write("Access denied to folder.");
            }
            else
            {

                // loop through each subdirectory
                foreach (DirectoryInfo d in directory.GetDirectories("*", SearchOption.AllDirectories))
                {
                    // create a new node
                    TreeNode t = new TreeNode(d.Name);
                    // populate the new node recursively
                    PopulateTree(d.FullName, t);
                    node.Nodes.Add(t); // add the node to the "master" node
                }

                // lastly, loop through each file in the directory, and add these as nodes
                foreach (FileInfo f in directory.GetFiles())
                {
                    // create a new node
                    TreeNode t = new TreeNode(f.Name);
                    // add it to the "master"
                    node.Nodes.Add(t);
                }
            }
        }
        catch (System.Exception e)
        {
            MessageBox.Show(e.Message, "Error Loading Directories", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
        }

    }

Answer 1

将try/catch块移动到foreach循环中,因此您可以在try块中使用填充代码.这样,遇到异常时,您不会退出循环.

foreach(var item in col)
{
  try
  {
     //do stuff with item
  }
  catch 
  {
     //yes, this is empty, but in this case it is okay as there is no other way
  }
}