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[英]How to check if a line in richTextBox1 is already exist or not in a text file?
[英]How do I check if one of the lines already exist in the text file?
string filename = "";
private void openToolStripMenuItem1_Click(object sender, EventArgs e)
{
OpenFileDialog theDialog = new OpenFileDialog();
theDialog.Title = "Open Text File";
theDialog.Filter = "TXT files|*.txt";
theDialog.InitialDirectory = @"C:\";
if (theDialog.ShowDialog() == DialogResult.OK)
{
lines = File.ReadAllLines(RecentFiles);
filename = theDialog.FileName;
for (int i = 0; i < lines.Length; i++)
{
recentfiles = new StreamWriter(RecentFiles, true);
recentfiles.WriteLine(theDialog.FileName);
recentfiles.Close();
items = File
.ReadLines(RecentFiles)
.Select(line => new ToolStripMenuItem()
{
Text = line
})
.ToArray();
recentFilesToolStripMenuItem.DropDownItems.AddRange(items);
}
TextFileContentToRichtextbox(filename);
}
}
我不确定在行上进行for循环是否正确。 但是,我要做的是打开一个新的文本文件,以检查它是否已存在于RecentFiles(RecentFiles.txt)
,如果不存在,就不要再写了。
遍历行,如果遍历所有行并且变量文件名不存在,则将其写入文本文件并更新项目。
Linq非常适合:
// if there are not any lines that equal the filename
if (!lines.Any(line => line.Equals(filename)))
{
// then write it into recent files text file
}
////以下代码仅在一行包含1个具有扩展名或任何文本的fileName时起作用。
if (lines.Contains(filename, StringComparer.OrdinalIgnoreCase))
{
//// lines contains
}
else
{
////lines doesnot contain file name
}
验证它是否完全满足您的要求。
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