问题
I want to notify my web view from button in html file and trigger the javascript:
function notify(str) {
window.external.notify(str);
}
The event captured using wv_ScriptNotify(..., ...):
void wv_ScriptNotify(object sender, NotifyEventArgs e)
{
Color c=Colors.Red;
if (e.CallingUri.Scheme =="ms-appx-web" || e.CallingUri.Scheme == "ms-appdata")
{
if (e.Value.ToLower() == "blue") c = Colors.Blue;
else if (e.Value.ToLower() == "green") c = Colors.Green;
}
appendLog(string.Format("Response from script at '{0}': '{1}'", e.CallingUri, e.Value), c);
}
I set the html file on ms-appx-web and it running well, and I realize that the html file must be store into local folder. So I change the ms-appx-web:///.../index.html to ms-appdata:///local/.../index.html.
Already search in microsoft forum and get this. On that thread there is a solution using resolver, but I'm still confusing, how can it notify from javascript like using window.external.notify? And what kind of event in C# side that will capture the "notify" from javascript other than "ScriptNotify"?
Update
There is a solution from here, example using the resolver and it said to use ms-local-stream:// rather than using ms-appdata://local so I can still use the ScriptNotify event. But unfortunately the example using the ms-appx that means using the InstalledLocation not the LocalFolder.
Trying to googling and search in msdn site for the documentation for ms-local-stream but the only documentation is just the format of ms-local-stream without any example like this ms-local-stream://appname_KEY/folder/file.
Based from that documentation, I made some sample to try it:
public sealed class StreamUriWinRTResolver : IUriToStreamResolver
{
/// <summary>
/// The entry point for resolving a Uri to a stream.
/// </summary>
/// <param name="uri"></param>
/// <returns></returns>
public IAsyncOperation<IInputStream> UriToStreamAsync(Uri uri)
{
if (uri == null)
{
throw new Exception();
}
string path = uri.AbsolutePath;
// Because of the signature of this method, it can't use await, so we
// call into a separate helper method that can use the C# await pattern.
return getContent(path).AsAsyncOperation();
}
/// <summary>
/// Helper that maps the path to package content and resolves the Uri
/// Uses the C# await pattern to coordinate async operations
/// </summary>
private async Task<IInputStream> getContent(string path)
{
// We use a package folder as the source, but the same principle should apply
// when supplying content from other locations
try
{
// My package name is "WebViewResolver"
// The KEY is "MyTag"
string scheme = "ms-local-stream:///WebViewResolver_MyTag/local/MyFolderOnLocal" + path; // Invalid path
// string scheme = "ms-local-stream:///WebViewResolver_MyTag/MyFolderOnLocal" + path; // Invalid path
Uri localUri = new Uri(scheme);
StorageFile f = await StorageFile.GetFileFromApplicationUriAsync(localUri);
IRandomAccessStream stream = await f.OpenAsync(FileAccessMode.Read);
return stream.GetInputStreamAt(0);
}
catch (Exception) { throw new Exception("Invalid path"); }
}
}
And inside my MainPage.xaml.cs:
protected override void OnNavigatedTo(NavigationEventArgs e)
{
// The 'Host' part of the URI for the ms-local-stream protocol needs to be a combination of the package name
// and an application-defined key, which identifies the specific resolver, in this case 'MyTag'.
Uri url = wv.BuildLocalStreamUri("MyTag", "index.html");
StreamUriWinRTResolver myResolver = new StreamUriWinRTResolver();
// Pass the resolver object to the navigate call.
wv.NavigateToLocalStreamUri(url, myResolver);
}
It always get the exception when it reach the StorageFile f = await StorageFile.GetFileFromApplicationUriAsync(localUri); line.
If anybody ever got this problem and already solved it, please advise.
回答1:
After debugging it, I found something interesting, the BuildLocalStreamUri part is already make the ms-local-stream automatically.
I made some changes on the getContent method inside StreamUriWinRTResolver class:
public sealed class StreamUriWinRTResolver : IUriToStreamResolver
{
/// <summary>
/// The entry point for resolving a Uri to a stream.
/// </summary>
/// <param name="uri"></param>
/// <returns></returns>
public IAsyncOperation<IInputStream> UriToStreamAsync(Uri uri)
{
if (uri == null)
{
throw new Exception();
}
string path = uri.AbsolutePath;
// Because of the signature of this method, it can't use await, so we
// call into a separate helper method that can use the C# await pattern.
return getContent(path).AsAsyncOperation();
}
/// <summary>
/// Helper that maps the path to package content and resolves the Uri
/// Uses the C# await pattern to coordinate async operations
/// </summary>
private async Task<IInputStream> getContent(string path)
{
// We use a package folder as the source, but the same principle should apply
// when supplying content from other locations
try
{
// Don't use "ms-appdata:///" on the scheme string, because inside the path
// will contain "/local/MyFolderOnLocal/index.html"
string scheme = "ms-appdata://" + path;
Uri localUri = new Uri(scheme);
StorageFile f = await StorageFile.GetFileFromApplicationUriAsync(localUri);
IRandomAccessStream stream = await f.OpenAsync(FileAccessMode.Read);
return stream.GetInputStreamAt(0);
}
catch (Exception) { throw new Exception("Invalid path"); }
}
}
Change the file path on the MainPage.xaml.cs:
protected override void OnNavigatedTo(NavigationEventArgs e)
{
// The 'Host' part of the URI for the ms-local-stream protocol needs to be a combination of the package name
// and an application-defined key, which identifies the specific resolver, in this case 'MyTag'.
Uri url = wv.BuildLocalStreamUri("MyTag", "/local/MyFolderOnLocal/index.html");
StreamUriWinRTResolver myResolver = new StreamUriWinRTResolver();
// Pass the resolver object to the navigate call.
wv.NavigateToLocalStreamUri(url, myResolver);
wv.ScriptNotify += wv_ScriptNotify;
}
protected override void wv_ScriptNotify(object sender, NavigationEventArgs e)
{
if (e.CallingUri.Scheme == "ms-local-stream")
{
// Do your work here...
}
}
来源：https://stackoverflow.com/questions/18872269/script-notify-for-ms-appdata