Android系统。 如何在WebView的ImageView上设置图像？

Question

I am using WebView to submit form values(I do not have access to API). Webview is invisible. User will fill just EditTexts. Webview fields will be filled using Javascript. The problem I have is CAPTCHA image. Web form has PNG image which contains CAPTCHA numbers.

HTML:

<img id="captcha_img" src="/service/INNCaptcha">

I want to take captcha image from WebView, and set it to ImageView. I tried this code:

webview.getSettings().setJavaScriptEnabled(true);
        webview.setWebViewClient(new WebViewClient() {
            @Override
            public void onPageFinished(WebView view, String url) {
                String javascript = "javascript: var form = document.getElementsByClassName('form');"
                        + "var body = document.getElementsByTagName('body');"
                        + "body[0].innerHTML = form[0].innerHTML;;";
                view.loadUrl(javascript);
                webview.setVisibility(View.VISIBLE);

                //THIS PIECE OF CODE RETURNING NULL BITMAP
                view.buildDrawingCache();
                Bitmap bmap = ivCaptcha.getDrawingCache();
                ivCaptcha.setImageBitmap(bmap);
            }
        });

Result: BitMap is null. I think I should identify exactly which image(PNG) I want to show. So my question is how to set image on ImageView from WebView in this case?

Answer 1

您必须在getDrawingCache();之前调用setDrawingCacheEnabled (true) getDrawingCache();

Answer 2

Check if you have enabled DOM on webview. Also, does it have a src link?