C# 子字符串（开发人员如何使用）

public string Substring(int startIndex);
public string Substring(int startIndex, int length);

public String Substring(Integer startIndex)
public String Substring(Integer startIndex, Integer length)

// public static void main
public static void Main(string [] args)
{
    string text = "Hello, world!";
    string substring = text.Substring(7);
    Console.WriteLine(substring);
}

' public static void main
Public Shared Sub Main(ByVal args() As String)
	Dim text As String = "Hello, world!"
	Dim substring As String = text.Substring(7)
	Console.WriteLine(substring)
End Sub

world!

'INSTANT VB TODO TASK: The following line uses invalid syntax:
'world!

public static void Main(string [] args)
{
    string text = "Hello, world!";
    string substring = text.Substring(7, 5);
    Console.WriteLine(substring);
}

Public Shared Sub Main(ByVal args() As String)
	Dim text As String = "Hello, world!"
	Dim substring As String = text.Substring(7, 5)
	Console.WriteLine(substring)
End Sub

world

'INSTANT VB TODO TASK: The following line uses invalid syntax:
'world

string [] array = { "apple", "banana", "orange" };
foreach (string str in array)
{
    string substring = str.Substring(1, 3); // substring starts from index 1
    Console.WriteLine(substring);
}

Dim array() As String = { "apple", "banana", "orange" }
For Each str As String In array
	Dim substring As String = str.Substring(1, 3) ' substring starts from index 1
	Console.WriteLine(substring)
Next str

ppl
ana
ran

'INSTANT VB TODO TASK: The following line uses invalid syntax:
'ppl ana ran

public static void Main(string [] args)
{
    string text = "Hello, world!";
    int startIndex = 7;
    int length = 5;
    if (startIndex >= 0 && startIndex < text.Length && startIndex + length <= text.Length)
    {
        string substring = text.Substring(startIndex, length);
        Console.WriteLine(substring);
    }
    else
    {
        Console.WriteLine("Invalid substring parameters.");
    }
}

Public Shared Sub Main(ByVal args() As String)
	Dim text As String = "Hello, world!"
	Dim startIndex As Integer = 7
	Dim length As Integer = 5
	If startIndex >= 0 AndAlso startIndex < text.Length AndAlso startIndex + length <= text.Length Then
		Dim substring As String = text.Substring(startIndex, length)
		Console.WriteLine(substring)
	Else
		Console.WriteLine("Invalid substring parameters.")
	End If
End Sub

using IronPdf;

class Program
{
    static void Main(string[] args)
    {
        var renderer = new ChromePdfRenderer();

        // 1. Convert HTML String to PDF
        var htmlContent = "<h1>Hello, IronPDF!</h1><p>This is a PDF from an HTML string.</p>";
        var pdfFromHtmlString = renderer.RenderHtmlAsPdf(htmlContent);
        pdfFromHtmlString.SaveAs("HTMLStringToPDF.pdf");

        // 2. Convert HTML File to PDF
        var htmlFilePath = "path_to_your_html_file.html"; // Specify the path to your HTML file
        var pdfFromHtmlFile = renderer.RenderHtmlFileAsPdf(htmlFilePath);
        pdfFromHtmlFile.SaveAs("HTMLFileToPDF.pdf");

        // 3. Convert URL to PDF
        var url = "https://ironpdf.com"; // Specify the URL
        var pdfFromUrl = renderer.RenderUrlAsPdf(url);
        pdfFromUrl.SaveAs("URLToPDF.pdf");
    }
}

Imports IronPdf

Friend Class Program
	Shared Sub Main(ByVal args() As String)
		Dim renderer = New ChromePdfRenderer()

		' 1. Convert HTML String to PDF
		Dim htmlContent = "<h1>Hello, IronPDF!</h1><p>This is a PDF from an HTML string.</p>"
		Dim pdfFromHtmlString = renderer.RenderHtmlAsPdf(htmlContent)
		pdfFromHtmlString.SaveAs("HTMLStringToPDF.pdf")

		' 2. Convert HTML File to PDF
		Dim htmlFilePath = "path_to_your_html_file.html" ' Specify the path to your HTML file
		Dim pdfFromHtmlFile = renderer.RenderHtmlFileAsPdf(htmlFilePath)
		pdfFromHtmlFile.SaveAs("HTMLFileToPDF.pdf")

		' 3. Convert URL to PDF
		Dim url = "https://ironpdf.com" ' Specify the URL
		Dim pdfFromUrl = renderer.RenderUrlAsPdf(url)
		pdfFromUrl.SaveAs("URLToPDF.pdf")
	End Sub
End Class

using IronPdf;
using System;
public class PdfGenerator
{
    public static void Main(string [] args)
    {
        License.LicenseKey = "License-Key";
        // Original large text from which we need to extract information
        string originalText = "IronPDF helps you generate PDF documents in .NET applications easily. Discover more about IronPDF at the official site.";
        // Using the Substring method to extract the part of the string that talks about IronPDF
        string importantInfo = originalText.Substring(0, 65);  // Extracts the first sentence
        // Create a PDF document with IronPDF
        var renderer = new ChromePdfRenderer();
        // Convert the extracted text to PDF
        PdfDocument pdf = renderer.RenderHtmlAsPdf($"<h1>Extracted Information</h1><p>{importantInfo}</p>");
        // Save the PDF to a file
        pdf.SaveAs("ExtractedInfo.pdf");
        // Confirmation output
        Console.WriteLine("PDF generated successfully with extracted information.");
    }
}

Imports IronPdf
Imports System
Public Class PdfGenerator
	Public Shared Sub Main(ByVal args() As String)
		License.LicenseKey = "License-Key"
		' Original large text from which we need to extract information
		Dim originalText As String = "IronPDF helps you generate PDF documents in .NET applications easily. Discover more about IronPDF at the official site."
		' Using the Substring method to extract the part of the string that talks about IronPDF
		Dim importantInfo As String = originalText.Substring(0, 65) ' Extracts the first sentence
		' Create a PDF document with IronPDF
		Dim renderer = New ChromePdfRenderer()
		' Convert the extracted text to PDF
		Dim pdf As PdfDocument = renderer.RenderHtmlAsPdf($"<h1>Extracted Information</h1><p>{importantInfo}</p>")
		' Save the PDF to a file
		pdf.SaveAs("ExtractedInfo.pdf")
		' Confirmation output
		Console.WriteLine("PDF generated successfully with extracted information.")
	End Sub
End Class