Xamarin.Android pdf生成器

Question

我Xamarin.Android最近一直在努力.我需要使用pdf生成器通过电子邮件发送报告.

我遇到过以下博客.我真的不知道要放什么FileStream fs = new FileStream (???????);.除此之外,我想在屏幕上打开或看到pdf.

using System;

using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using System.IO;
using XamiTextSharpLGPL;
using iTextSharp.text;
using iTextSharp.text.pdf;
using iTextSharp;



namespace PDFAapp
{
    [Activity (Label = "PDFAapp", MainLauncher = true, Icon = "@drawable/icon")]
    public class MainActivity : Activity
    {
        int count = 1;

        protected override void OnCreate (Bundle bundle)
        {
            base.OnCreate (bundle);

            // Set our view from the "main" layout resource
            SetContentView (Resource.Layout.Main);

            FileStream fs = new FileStream (???????);
            Document document = new Document (PageSize.A4, 25, 25, 30, 30);
            PdfWriter writer = PdfWriter.GetInstance (document, fs);
            document.Add(new Paragraph("Hello World"));
            document.Close();
            writer.Close();
            fs.Close();
        }
    }
}

编辑1:

有以下代码打开生成的Pdf,但它显示pdf格式无效.

Java.IO.File file = new Java.IO.File(filePath);
Intent intent = new Intent(Intent.ActionView);
intent.SetDataAndType(Android.Net.Uri.FromFile(file), "application/pdf");
StartActivity(intent);

Answer 1

首先确保Manifest您允许的 文件WriteExternalStorage

要在外部存储上读取或写入文件,您的应用必须获取READ_EXTERNAL_STORAGE或WRITE_EXTERNAL_STORAGE系统权限.例如:

 <manifest ...>
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 </manifest>

FileStream构造函数(其中之一)接受路径的字符串,FileMode因此示例解决方案将是.

  var directory = new Java.IO.File(Android.OS.Environment.ExternalStorageDirectory, "pdf").ToString();
  if (!Directory.Exists(directory))
  {
      Directory.CreateDirectory(directory);
  }

  var path = Path.Combine(directory, "myTestFile.pdf");
  var fs = new FileStream(path, FileMode.Create);

这会将名为"pdf"的文件夹创建到外部存储中,然后创建pdf文件.可以包含附加代码以在创建文件之前检查文件是否存在.

编辑:完整的示例,刚刚在我的设备上测试:

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);

            var directory = new Java.IO.File(Android.OS.Environment.ExternalStorageDirectory, "pdf").ToString();
            if (!Directory.Exists(directory))
            {
                Directory.CreateDirectory(directory);
            }

            var path = Path.Combine(directory, "myTestFile.pdf");

            if (File.Exists(path))
            {
                File.Delete(path);
            }

            var fs = new FileStream(path, FileMode.Create);
            Document document = new Document(PageSize.A4, 25, 25, 30, 30);
            PdfWriter writer = PdfWriter.GetInstance(document, fs);
            document.Open();
            document.Add(new Paragraph("Hello World"));
            document.Close();
            writer.Close();
            fs.Close();

            Java.IO.File file = new Java.IO.File(path);
            Intent intent = new Intent(Intent.ActionView);
            intent.SetDataAndType(Android.Net.Uri.FromFile(file), "application/pdf");
            StartActivity(intent);
        }