如何在vb.net中替换字符串

Question

Here's my code:

    Dim lQuotes As Char = Convert.ToChar(&H201C) ' “
    Dim rQuotes As Char = Convert.ToChar(&H201D) ' ”

    Dim BP01 As String =
        String.Format("<li>{0}<em>{2}</em>{1} ― <strong>{3}</strong></li>", lQuotes, rQuotes, BP1.Text, BPGB1.Text)

Dim objWriter As New System.IO.StreamWriter("d:Temp 1.txt", True)


objWriter.WriteLine(BP01)

objWriter.Close()

If BP1 Textbox is empty, That means If there's no data to input, can we replace it with "Data is empty" word or else with nothing ... like this ""

For example:

Replace BP01 to something else so that this line "Data is empty" is displayed

Note: I don't want to display these html codes like ... < li >, < em > etc.

Answer 1

Check your input values and act accordingly instead of replacing

Dim BP01 As String

If (string.IsNullOrWhiteSpace(BP1.Text) Or string.IsNullOrWhiteSpace(BPGB1.Text)) Then
    BP01 = "Data Is Empty"
Else
    BP01 = String.Format("<li>{0}<em>{2}</em>{1} ― <strong>{3}</strong></li>", lQuotes, rQuotes, BP1.Text, BPGB1.Text)
End If

If you would like to skip output entirely you can just negate ( Not ) both your If conditions to only act on valid input (BP1 and BPGB1 must not be empty).

If (Not string.IsNullOrWhiteSpace(BP1.Text) And Not string.IsNullOrWhiteSpace(BPGB1.Text)) Then
    BP01 = String.Format("<li>{0}<em>{2}</em>{1} ― <strong>{3}</strong></li>", lQuotes, rQuotes, BP1.Text, BPGB1.Text)
    objWriter.WriteLine(BP01)
End If