的Process.Start返回null [英] Process.Start returns null
问题描述
我写一个启动一个随机文件目录中的程序。该文件可以是任何时间,但大多是视频或图像文件。 $ B $每次我启动的文件,我想关闭之前的b打开之一。
的代码是:
i am writing a program that launches a random file in a directory. the file can be of any time, but mostly video or image files. each time i launch a file i want to close the previous opened one. the code is:
string FolderSelected = "";
string FileName = "";
Process proc;
List<string> FilesDisplayed = new List<string>();
public Form1()
{
InitializeComponent();
}
private void button2_Click(object sender, EventArgs e)
{
if (FolderSelected == string.Empty)
FolderSelected = Properties.Settings.Default.FilesDefaultFolder;
if (proc != null)
{
proc.CloseMainWindow();
proc.Close();
}
FileName = FetchRandomFile();
proc = Process.Start(FileName);
}
的问题是,我不断收到PROC = NULL(文件被正确启动),我不能为了关闭它获取先前打开的过程。我知道,.NET重用流程,这就是为什么它返回NULL,但我需要覆盖此行为。
请大家帮忙,
盖伊
the problem is, that i keep getting proc = null (the file is launched properly) and i cannot fetch the previously opened process in order to close it. I know that .NET reuses processes and thats why it returns Null but i need to override this behavior. please help, Guy.
推荐答案
编辑:感谢leppie的评论,我怀疑我知道答:我的猜测是,你在启动类似的图像,它的重用现有的进程中打开而不是创建一个新的文件
Thanks to leppie's comment, I suspect I know the answer: my guess is that you're "starting" something like an image, and it's reusing an existing process to open the document instead of creating a new one.
我受够了这个简单的测试程序转载此:
I've reproduced this with this simple test app:
using System;
using System.Diagnostics;
public class Test
{
static void Main()
{
Process proc = Process.Start("image.tif");
Console.WriteLine(proc == null);
}
}
这将打印真,因为它使用 DLLHOST.EXE
举办的Windows图像查看器,而不是创建一个新的进程。
This prints "true" because it's using dllhost.exe
to host the Windows Image Viewer, rather than creating a new process.
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