我正在使用帖子调用来获取带有PDF所有数据的字节流,然后我想使用Android中的默认程序打开PDF。以后会为iOS做。
这是我的代码:
async void OnItemSelected(object sender, SelectedItemChangedEventArgs e)
{
Publication p = (Publication)e.SelectedItem;
Debug.WriteLine(p);
if (p.folderID.Equals("-1"))
{
using (Stream respStream = await post(p.docNum))
{
byte[] buffer = new byte[respStream.Length];
respStream.Read(buffer, 0, buffer.Length);
string path = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
File.WriteAllBytes(path + "foo.pdf", buffer);
Device.OpenUri(new Uri(path + "foo.pdf"));
}
}
else
{
await Navigation.PushAsync(new PublicationsPage(p.folderID));
}
}
private async Task<Stream> post(string id)
{
Dictionary<string, string> dir = new Dictionary<string, string>();
dir.Add("LoginID", App.user.login_id);
dir.Add("docID", id);
var jsonReq = JsonConvert.SerializeObject(dir);
Debug.WriteLine("req: " + (String)jsonReq);
var content = new StringContent(jsonReq, Encoding.UTF8, "application/json");
var response = await client.PostAsync(url, content);
var responseStream = await response.Content.ReadAsStreamAsync();
return responseStream;
}
我现在已经下载了PDF作为字节流,然后将窗口弹出然后关闭。我该怎么办?我宁愿不支付任何包裹,理想情况下,我想提示使用哪个程序打开。
iOS和android之间的文件系统不同。因此,您需要使用dependencyService来保存和加载PDF文件在不同的平台上。
感谢 @b.6242,在本期中, @b.6242已在Android和iOS中使用DependencyService
实现了它,您可以参考它。
这是关于如何在不同平台上使用文件系统的问题。
通过以下内容让它起作用:https://developer.xamarin.com/recipes/cross-platform/xamarin-forms/controls/controls/display-pdf/
在上面的代码中,将onitemsemectect与此更改为PDFViewPage使用上面链接中描述的自定义WebView:
async void OnItemSelected(object sender, SelectedItemChangedEventArgs e)
{
Publication p = (Publication)e.SelectedItem;
Debug.WriteLine(p);
if (p.folderID.Equals("-1"))
{
using (Stream respStream = await post(p.docNum))
{
byte[] buffer = new byte[respStream.Length];
respStream.Read(buffer, 0, buffer.Length);
string path = System.Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
File.WriteAllBytes(path + "foo.pdf", buffer);
await Navigation.PushAsync(new PDFViewPage(path + "foo.pdf"));
//Device.OpenUri(new Uri(path + "foo.pdf"));
}
}
else
{
await Navigation.PushAsync(new PublicationsPage(p.folderID));
}
}