当你按住一个恰好是图像的可见元素时,我一直在尝试从UIWebView
保存图像。我很难找到如何将UILongPressGestureRecognizer
的触摸点转换为Javascript获得正确位置所需的点数。我认为它与webView的scrollView内容插图有关,但我不太确定。
我很感激提供任何帮助。
代码:
- (void)longPress:(UILongPressGestureRecognizer *)sender
{
if (sender.state == UIGestureRecognizerStateBegan)
{
CGPoint pt = [sender locationInView:self.webView];
CGPoint offset;
offset.x = [[self.webView stringByEvaluatingJavaScriptFromString:@"window.pageXOffset"]integerValue];
offset.y = [[self.webView stringByEvaluatingJavaScriptFromString:@"window.pageYOffset"]integerValue];
CGSize windowSize;
windowSize.width = [[self.webView stringByEvaluatingJavaScriptFromString:@"window.innerWidth"]integerValue];
windowSize.height = [[self.webView stringByEvaluatingJavaScriptFromString:@"window.innerHeight"]integerValue];
CGFloat f = windowSize.width / self.webView.frame.size.width;
pt.x = (pt.x * f);
pt.y = (pt.y - self.webView.scrollView.contentInset.top) * f;
NSString *js = [NSString stringWithFormat:@"document.elementFromPoint(%f, %f).tagName", pt.x, pt.y];
NSString *tagName = [self.webView stringByEvaluatingJavaScriptFromString:js];
if (tagName && [tagName caseInsensitiveCompare:@"IMG"] == NSOrderedSame)
{
NSString *imgURL = [NSString stringWithFormat:@"document.elementFromPoint(%f, %f).src", pt.x, pt.y];
NSString *urlToDownload = [self.webView stringByEvaluatingJavaScriptFromString:imgURL];
NSArray *validImageTypes = @[@".jpg",@".jpeg",@".gif",@".tif",@".tiff",@".ico",@".bmp",@".bmpf",@".cur",@".xbm",@".png"];
for (NSString *sub in validImageTypes)
{
if (urlToDownload.length >= sub.length)
{
NSString *extension = [urlToDownload substringFromIndex:MAX(urlToDownload.length - sub.length, 0)];
if ([extension caseInsensitiveCompare:sub] == NSOrderedSame)
{
// Image found, proceed to download (code omitted)
break;
}
}
}
}
}
}
答案 0 :(得分:2)
以下代码现在似乎对我有用。我必须考虑UIWebView
UIScrollView
contentInset.top
属性,然后从pt.y
中减去该值,然后将其乘以因子f
:
- (void)longPress:(UILongPressGestureRecognizer *)sender
{
if (sender.state == UIGestureRecognizerStateBegan)
{
CGPoint pt = [sender locationInView:self.webView];
CGPoint offset;
offset.x = [[self.webView stringByEvaluatingJavaScriptFromString:@"window.pageXOffset"]integerValue];
offset.y = [[self.webView stringByEvaluatingJavaScriptFromString:@"window.pageYOffset"]integerValue];
CGSize windowSize;
windowSize.width = [[self.webView stringByEvaluatingJavaScriptFromString:@"window.innerWidth"]integerValue];
windowSize.height = [[self.webView stringByEvaluatingJavaScriptFromString:@"window.innerHeight"]integerValue];
CGFloat f = windowSize.width / self.webView.frame.size.width;
pt.x = (pt.x * f);
pt.y = (pt.y - self.webView.scrollView.contentInset.top) * f;
NSString *js = [NSString stringWithFormat:@"document.elementFromPoint(%f, %f).tagName", pt.x, pt.y];
NSString *tagName = [self.webView stringByEvaluatingJavaScriptFromString:js];
if (tagName && [tagName caseInsensitiveCompare:@"IMG"] == NSOrderedSame)
{
NSString *imgURL = [NSString stringWithFormat:@"document.elementFromPoint(%f, %f).src", pt.x, pt.y];
NSString *urlToDownload = [self.webView stringByEvaluatingJavaScriptFromString:imgURL];
NSArray *validImageTypes = @[@".jpg",@".jpeg",@".gif",@".tif",@".tiff",@".ico",@".bmp",@".bmpf",@".cur",@".xbm",@".png"];
for (NSString *sub in validImageTypes)
{
if (urlToDownload.length >= sub.length)
{
NSString *extension = [urlToDownload substringFromIndex:MAX(urlToDownload.length - sub.length, 0)];
if ([extension caseInsensitiveCompare:sub] == NSOrderedSame)
{
// Image found, proceed to download (code omitted)
break;
}
}
}
}
}
}