android.webkit.WebView#destroyDrawingCache ( )源码实例Demo

/**
 * Create a picture out of {@link WebView}'s whole content
 *
 * @param webView The WebView to get contents from
 * @return A {@link Bitmap} or null
 */
@Nullable
public static Bitmap getBitmapFromWebView(final WebView webView) {
    try {
        //Measure WebView's content
        int widthMeasureSpec = View.MeasureSpec.makeMeasureSpec(View.MeasureSpec.UNSPECIFIED, View.MeasureSpec.UNSPECIFIED);
        int heightMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        webView.measure(widthMeasureSpec, heightMeasureSpec);
        webView.layout(0, 0, webView.getMeasuredWidth(), webView.getMeasuredHeight());

        //Build drawing cache and store its size
        webView.buildDrawingCache();
        int measuredWidth = webView.getMeasuredWidth();
        int measuredHeight = webView.getMeasuredHeight();

        //Creates the bitmap and draw WebView's content on in
        Bitmap bitmap = Bitmap.createBitmap(measuredWidth, measuredHeight, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        canvas.drawBitmap(bitmap, 0, bitmap.getHeight(), new Paint());

        webView.draw(canvas);
        webView.destroyDrawingCache();

        return bitmap;
    } catch (Exception | OutOfMemoryError e) {
        e.printStackTrace();
        return null;
    }
}
 

/**
 * Create a picture out of {@link WebView}'s whole content
 *
 * @param webView The WebView to get contents from
 * @return A {@link Bitmap} or null
 */
@Nullable
public static Bitmap getBitmapFromWebView(final WebView webView) {
    try {
        //Measure WebView's content
        int widthMeasureSpec = View.MeasureSpec.makeMeasureSpec(View.MeasureSpec.UNSPECIFIED, View.MeasureSpec.UNSPECIFIED);
        int heightMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        webView.measure(widthMeasureSpec, heightMeasureSpec);
        webView.layout(0, 0, webView.getMeasuredWidth(), webView.getMeasuredHeight());

        //Build drawing cache and store its size
        webView.buildDrawingCache();
        int measuredWidth = webView.getMeasuredWidth();
        int measuredHeight = webView.getMeasuredHeight();

        //Creates the bitmap and draw WebView's content on in
        Bitmap bitmap = Bitmap.createBitmap(measuredWidth, measuredHeight, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        canvas.drawBitmap(bitmap, 0, bitmap.getHeight(), new Paint());

        webView.draw(canvas);
        webView.destroyDrawingCache();

        return bitmap;
    } catch (Exception | OutOfMemoryError e) {
        e.printStackTrace();
        return null;
    }
}
 

/**
 * Create a picture out of {@link WebView}'s whole content
 *
 * @param webView The WebView to get contents from
 * @return A {@link Bitmap} or null
 */
@Nullable
public static Bitmap getBitmapFromWebView(WebView webView) {
    try {
        //Measure WebView's content
        int widthMeasureSpec = View.MeasureSpec.makeMeasureSpec(View.MeasureSpec.UNSPECIFIED, View.MeasureSpec.UNSPECIFIED);
        int heightMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        webView.measure(widthMeasureSpec, heightMeasureSpec);
        webView.layout(0, 0, webView.getMeasuredWidth(), webView.getMeasuredHeight());

        //Build drawing cache and store its size
        webView.buildDrawingCache();
        int measuredWidth = webView.getMeasuredWidth();
        int measuredHeight = webView.getMeasuredHeight();

        //Creates the bitmap and draw WebView's content on in
        Bitmap bitmap = Bitmap.createBitmap(measuredWidth, measuredHeight, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        canvas.drawBitmap(bitmap, 0, bitmap.getHeight(), new Paint());

        webView.draw(canvas);
        webView.destroyDrawingCache();

        return bitmap;
    } catch (Exception | OutOfMemoryError e) {
        e.printStackTrace();
        return null;
    }
}
 

private void closeCache(@NonNull WebView view) {
    view.setDrawingCacheEnabled(false);
    view.destroyDrawingCache();
}