Question

我有一个问题是循环浏览WebView等待WebView完全加载，用javascript函数填充webPage的形式，然后创建webView的图像。

for (Integer id : idToQuery) {

    webView = new WebView(ctx);
    webView.getSettings().setJavaScriptEnabled(true);
    webView.addJavascriptInterface(new getDataJSForPrint(), "Android");

    webView.setWebViewClient(new WebViewClient(){
        @Override
        public void onPageFinished(WebView view, String url) {
            super.onPageFinished(view, url);

            String someJsonData = "Lot of Data"; //only for example

            //init function use data to fill form in webpage
            webView.loadUrl("javascript:init(" + someJsonData+ ")");

            //get html String from WebView when finished to load                
            webView.loadUrl("javascript:window.Android.getHtmlFromWebView('<html>'+document.getElementsByTagName('html')[0].innerHTML+'</html>');");
        }
    });

    webView.loadUrl("file:///android_asset/index.html");

}

现在我需要等待getHtmlFromWebView完成执行才能传递给其他WebView，我需要创建一个WebView屏幕并将其保存为图像

public class getDataJSForPrint{

    @JavascriptInterface
    public void getHtmlFromWebView (String html) throws DocumentException, IOException{

        //got this piece of code in another answer of stackoverflow
        File imageTemp = new File (Environment.getExternalStorageDirectory(), "tmpImag.jpeg");

        webView.measure(MeasureSpec.makeMeasureSpec(
                MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED),
                MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
        webView.layout(0, 0, webView.getMeasuredWidth(),
                webView.getMeasuredHeight());
        webView.setDrawingCacheEnabled(true);
        webView.buildDrawingCache();

        Bitmap bm = Bitmap.createBitmap(webView.getMeasuredWidth(),
                webView.getMeasuredHeight(), Bitmap.Config.ARGB_8888);

        Canvas bigcanvas = new Canvas(bm);
        Paint paint = new Paint();
        int iHeight = bm.getHeight();

        bigcanvas.drawBitmap(bm, 0, iHeight, paint);
        webView.draw(bigcanvas);


        if (bm != null) {
            try {
                OutputStream fOut = null;
                fOut = new FileOutputStream(imageTemp);

                bm.compress(Bitmap.CompressFormat.JPEG, 50, fOut);
                fOut.flush();
                fOut.close();
                bm.recycle();

            } catch (Exception e) {
                e.printStackTrace();
            }
        }


    }

}

我尝试了

synchronized (object) { object.wait(); }

在loadUrl之后尝试在getHtmlFromWebView结束时通知它，但显然它不起作用。

在FOR循环转到下一个项目之前，我该怎么做才能等待getHtmlFromWebView完成？

谢谢你：）

Answer 1

我认为您的要求不需要for循环。您可以使用recursive个功能。试试这个

//for ArrayList; other appropriate methods if idToQuery is not ArrayList
int count = idToQuery.size();
int index = 0;

private void loadWebView() {
webView = new WebView(ctx);
    webView.getSettings().setJavaScriptEnabled(true);
    webView.addJavascriptInterface(new getDataJSForPrint(), "Android");

    webView.setWebViewClient(new WebViewClient(){
        @Override
        public void onPageFinished(WebView view, String url) {
            super.onPageFinished(view, url);

            String someJsonData = "Lot of Data"; //only for example

            //init function use data to fill form in webpage
            webView.loadUrl("javascript:init(" + someJsonData+ ")");

            //get html String from WebView when finished to load                
            webView.loadUrl("javascript:window.Android.getHtmlFromWebView('<html>'+document.getElementsByTagName('html')[0].innerHTML+'</html>');");
        }
    });

    webView.loadUrl("file:///android_asset/index.html");
}

//Call the loadWebView function again after the bitmap operation. Increment the index each time. Then you can compare it with total count to control how many times you wan to call    loadWebView function
public class getDataJSForPrint{

        @JavascriptInterface
        public void getHtmlFromWebView (String html) throws DocumentException, IOException{

            //got this piece of code in another answer of stackoverflow
            File imageTemp = new File (Environment.getExternalStorageDirectory(), "tmpImag.jpeg");

            webView.measure(MeasureSpec.makeMeasureSpec(
                    MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED),
                    MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
            webView.layout(0, 0, webView.getMeasuredWidth(),
                    webView.getMeasuredHeight());
            webView.setDrawingCacheEnabled(true);
            webView.buildDrawingCache();

            Bitmap bm = Bitmap.createBitmap(webView.getMeasuredWidth(),
                    webView.getMeasuredHeight(), Bitmap.Config.ARGB_8888);

            Canvas bigcanvas = new Canvas(bm);
            Paint paint = new Paint();
            int iHeight = bm.getHeight();

            bigcanvas.drawBitmap(bm, 0, iHeight, paint);
            webView.draw(bigcanvas);


            if (bm != null) {
                try {
                    OutputStream fOut = null;
                    fOut = new FileOutputStream(imageTemp);

                    bm.compress(Bitmap.CompressFormat.JPEG, 50, fOut);
                    fOut.flush();
                    fOut.close();
                    bm.recycle();

                } catch (Exception e) {
                    e.printStackTrace();
                }
            }


            index++;
            if (index < count) {
                loadWebView()
            }


        }

    }

循环遍历WebView并等待onPageFinished完成

1 个答案: