C# 如果满足条件，如何使用 RichTextBox 中的字符串填充 ComboBox

Question

I am trying to populate a combo box with lines from a rich text box. But only if the last 6 characters of a line in the rich text box contains the string "device". I do not know the amount of lines in the rich text box and the amount of lines that contain the string "device", until runtime.

Let's say there are 6 lines in the combo box and 2 items that contain the string "device". But both numbers can and do change during runtime.

int IntCountLines is equal to the amount of lines in the rich text box. int IntNumberOfDevices is equal to the number of lines that contain the string "device" (in the last 6 characters) in the rich text box.

The first line [0] in the rich text box is always ignored. So, starting at line [1].

If line 1 in the rich text box contains the string "device", I want to add it to the combo box. If it does not, then move to line 2 and check that. If this contains the string "device" add it to the combo box. If it does not, then move to line 3 and so on.

int IntCountLines

int IntNumberOfDevices.

Richtextbox name is: RtxtAdbOutput.

ComboBox name is: CmbIPs.

I have:

StrTmpOutput = rtxtAdbOutput.Lines[1].Substring(rtxtAdbOutput.Lines[1].Length - 6);

if (StrTmpOutput == "device")
{
    CmbIPs.Items.Add(rtxtAdbOutput.Lines[1].Remove(rtxtAdbOutput.Lines[1].Length - 7));
}



StrTmpOutput = rtxtAdbOutput.Lines[2].Substring(rtxtAdbOutput.Lines[2].Length - 6);

if (StrTmpOutput == "device")
{
    CmbIPs.Items.Add(rtxtAdbOutput.Lines[2].Remove(rtxtAdbOutput.Lines[2].Length - 7));
}


StrTmpOutput = rtxtAdbOutput.Lines[3].Substring(rtxtAdbOutput.Lines[3].Length - 6);

if (StrTmpOutput == "device")
{
    CmbIPs.Items.Add(rtxtAdbOutput.Lines[3].Remove(rtxtAdbOutput.Lines[3].Length - 7));
}

And so on. But do not know the amount of lines until runtime means I do not know how long to carry on adding if statements. Plus, it gives errors if it is an empty line (as it tries to strip 7 characters from the end of a string that does not exist though I could put in some error checking to stop this).

Is there any way I can improve this with a for loop or similar?

I want to keep doing this until the amount of lines added to the combobox matches the value of IntNumberOfDevices.

Answer 1

You can use a combination of the List<T>.ForEach() method and the String.EndsWith()

rtxtAdbOutput.Lines.ToList()
    .GetRange(1, rtxtAdbOutput.Lines.Count() - 1)
    .Where(line => line.EndsWith("device")).ToList()
    .ForEach(validLine => CmbIPs.Items.Add(validLine.Remove(validLine.Length - 7)));

What this does is get all of the lines with an index higher than 0 as a list, then selects the ones that end with "device" using String.EndsWith , then for each of those adds them to the combo box using ForEach() .

DotnetFiddle demonstrating it

String.EndsWith documentation

List.ForEach documentation