Android Question WebView + local picture

Akwa · Mar 22, 2023

Hello,
I know that this question was already posted here one or two years ago. Unfortunately, none of the proposed solutions, in this forum, and around the web, have worked.

I have statics html pages, that have some <img src="picture.png">, that I display in a webview. I have no other solution than that.

At launch, I copy all the files (html, png) in the DirInternal (I tried also DirDefaultExternal).

I set every flags I found :

B4X:

    Dim ws As WebSettings
    ws = wve.GetSettings
    ws.SetAllowContentAccess(True)
    ws.SetAllowFileAccess(True)
    ws.SetBlockNetworkImage(False)
    ws.SetBlockNetworkLoads(False)
    ws.SetLoadsImagesAutomatically(True)
    ws.SetSupportZoom(False)
    ws.SetAppCacheEnabled(True)
    
    Dim joWebview As JavaObject = WebView1
    Dim joSettings As JavaObject = joWebview.RunMethod("getSettings", Null)
    Dim r As Reflector
    r.Target = joSettings
    r.RunMethod2("setAllowUniversalAccessFromFileURLs", True, "java.lang.boolean")
    r.RunMethod2("setDomStorageEnabled", True, "java.lang.boolean")
    r.RunMethod2("setMixedContentMode", 0x00000000, "java.lang.int")
    r.RunMethod2("setAllowFileAccess", True, "java.lang.boolean")
    r.RunMethod2("setAllowFileAccessFromFileURLs", True, "java.lang.boolean")

Then I load the page :

B4X:

Dim x As XUI
    Dim url As String =  x.FileUri(File.DirInternal, "index.htm")
    WebView1.LoadUrl(url)

Links between page works, but every pictures appears as a broken icon.

Thanks.

Akwa · Mar 22, 2023

Maybe this page is the solution :
https://developer.android.com/develop/ui/views/layout/webapps/load-local-content#java
Unfortunately, I'm totally unable to convert this Java code into B4A, using JavaObject or Reflector...
Thanks.

drgottjr · Mar 22, 2023

based on your description, and making no other assumptions as to any unrevealed intentions - if any - the code below is all you need to display an image in a webview. delete and burn the rest of your code.

B4X:

    webview.Initialize("webview")
    Activity.AddView(webview, 0%x,0%y,100%x,100%y)

    Dim html As String = $"<!DOCTYPE html>
    <html>
    <head>
    </head>
    <body>the image you requested:<br>
    <img src="file:///android_asset/b4x.jpg" width='300px'>
    </body>
    
    </html>"$
    webview.LoadHtml(html)

'     ******* OR YOU CAN DO IT THIS WAY ******
'    Dim x As XUI
'    Dim url As String =  x.FileUri(File.DirAssets, "akwa.txt")
'    webview.LoadUrl(url)

i attach an example showing the output. (both methods produce the same result)
please add b4x.jpg to your project (in your files folder).
please add akwa.txt to your project (in your files folder) if you use the second method. you can leave it as ".txt" (forum does not uploads with ".html" suffix).

use for any other purpose than as described in the original post may not work and may require a different solution.

Erel · Mar 22, 2023

[B4X] Use WebView to show large images

Better to use: [B4X] HugeImageView - show very large images Depends on: XUI and JavaObject. 'xui is a global XUI object. Private Sub ShowImage(WV As WebView, Dir As String, FileName As String) #if B4A Dim jo As JavaObject = Me jo.InitializeContext 'comment this line if calling this...

www.b4x.com

Akwa · Mar 22, 2023

Erel said:
[B4X] Use WebView to show large images

Better to use: [B4X] HugeImageView - show very large images Depends on: XUI and JavaObject. 'xui is a global XUI object. Private Sub ShowImage(WV As WebView, Dir As String, FileName As String) #if B4A Dim jo As JavaObject = Me jo.InitializeContext 'comment this line if calling this...

www.b4x.com

No no Erel, it's not a problem of large picture, it's a matter of some sort of static local WebApp, to simplify the design of the page.

Akwa · Mar 22, 2023

drgottjr said:
based on your description, and making no other assumptions as to any unrevealed intentions - if any - the code below is all you need to display an image in a webview. delete and burn the rest of your code.

i attach an example showing the output. (both methods produce the same result)
please add b4x.jpg to your project (in your files folder).
please add akwa.txt to your project (in your files folder) if you use the second method. you can leave it as ".txt" (forum does not uploads with ".html" suffix).

use for any other purpose than as described in the original post may not work and may require a different solution.

Thanks ! At first it doesn't work. And suddenly, I discovered it works in Release Mode, but not in Debug Mode !

@Erel, is there a reason the code works in Release and not in Debug mode ?

In debug mode, I have "Impossible to load the page ....... net: ERR_ACCESS_DENIED"

Erel · Mar 22, 2023

Try that code. It should work in both debug and release modes.

Akwa said:
@Erel, is there a reason the code works in Release and not in Debug mode ?

Yes, the files are placed in a different location in debug mode.

Android Question WebView + local picture

Akwa

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Akwa

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drgottjr

Expert

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Erel

B4X founder

[B4X] Use WebView to show large images

Akwa

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[B4X] Use WebView to show large images

Akwa

Member

Erel

B4X founder

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