blocks|key|829529|text|我更喜欢这样做：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|829530|1.+Get+the+SRC+attribute+of+the+image.
2.+Use+ImageIO.read+to+read+the+image+onto+a+BufferedImage
3.+Save+the+BufferedImage+using+ImageIO.write+function|code-block|syntax|javascript|829531|例如|829532|String+src+=+imgElement.getAttribute('src');
BufferedImage+bufferedImage+=+ImageIO.read(new+URL(src));
File+outputfile+=+new+File("saved.png");
ImageIO.write(bufferedImage,+"png",+outputfile);|829533|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I prefer doing something like this : 

<pre><code>1. Get the SRC attribute of the image.
2. Use ImageIO.read to read the image onto a BufferedImage
3. Save the BufferedImage using ImageIO.write function
</code></pre>

For e.g.

<pre class="lang-java prettyprint-override"><code>String src = imgElement.getAttribute('src');
BufferedImage bufferedImage = ImageIO.read(new URL(src));
File outputfile = new File("saved.png");
ImageIO.write(bufferedImage, "png", outputfile);

</code></pre>

blocks|key|829632|text|如果你需要测试镜像是否可用并且存在，你可以这样做：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|829633|protected+boolean+isResourceAvailableByUrl(String+resourceUrl)+{
++++//+backup+current+url,+to+come+back+to+it+in+future
++++String+currentUrl+=+webDriver.getCurrentUrl();
++++try+{
++++++++//+try+to+get+image+by+url
++++++++webDriver.get(resourceUrl);
++++++++//+if+"resource+not+found"+message+was+not+appeared+-+image+exists
++++++++return+webDriver.findElements(RESOURCE_NOT_FOUND).isEmpty();
++++}+finally+{
++++++++//+back+to+page
++++++++webDriver.get(currentUrl);
++++}
}|code-block|syntax|javascript|829634|但您需要确保，在执行此方法之前，通过currentUrl确实会让您重新打开页面。在我的情况下就是这样。如果没有-您可以尝试使用：|829635|webDriver.navigate().back()|829636|而且，不幸的是，似乎没有任何机会来分析响应状态代码。这就是为什么你需要在NOT_FOUND页面上找到任何特定的网页元素，并检查它是否出现过，然后决定--图像不存在。|829637|这只是一个变通办法，因为我找不到任何正式的解决方法。|829638|注意:如果您使用授权会话获取资源，而不能仅通过ImageIO或严格通过HttpClient下载，则此解决方案非常有用。|829639|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|W|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|Y|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

If you need to test that image is available and exists, you may do like this:

<pre><code>protected boolean isResourceAvailableByUrl(String resourceUrl) {
 // backup current url, to come back to it in future
 String currentUrl = webDriver.getCurrentUrl();
 try {
 // try to get image by url
 webDriver.get(resourceUrl);
 // if "resource not found" message was not appeared - image exists
 return webDriver.findElements(RESOURCE_NOT_FOUND).isEmpty();
 } finally {
 // back to page
 webDriver.get(currentUrl);
 }
}
</code></pre>

But you need to be sure, that going through currentUrl will really turn you back on page before execution of this method. In my case it was so. If not - you may try to use:

<pre><code>webDriver.navigate().back()
</code></pre>

And also, unfortunately, as it seems, there is no any chance to analyze response status code. That's why you need to find any specific web element on NOT_FOUND page and check that it was appeared and decide then - that image doesn't exist.

It is just workaround, cause I found no any official way to solve it.

NOTE:
This solution is helpful in case when you use authorized session to get resource, and can't just download it by ImageIO or strictly by HttpClient.

blocks|key|829791|text|另一个最正确的解决方案是通过简单的HTTP请求直接下载它。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|829792|您可以使用webDriver的用户会话，因为它存储cookie。|829793|在我的example中，我只是分析它返回的状态代码。如果为200，则图像存在，并且可用于显示或下载。如果你真的需要下载文件本身-你可以从httpResponse实体中获取所有的图像数据(使用它作为简单的输入流)。|offset|length|829794|//+just+look+at+your+cookie's+content+(e.g.+using+browser)
//+and+import+these+settings+from+it
private+static+final+String+SESSION_COOKIE_NAME+=+"JSESSIONID";
private+static+final+String+DOMAIN+=+"domain.here.com";
private+static+final+String+COOKIE_PATH+=+"/cookie/path/here";

protected+boolean+isResourceAvailableByUrl(String+resourceUrl)+{
++++HttpClient+httpClient+=+new+DefaultHttpClient();
++++HttpContext+localContext+=+new+BasicHttpContext();
++++BasicCookieStore+cookieStore+=+new+BasicCookieStore();
++++//+apply+jsessionid+cookie+if+it+exists
++++cookieStore.addCookie(getSessionCookie());
++++localContext.setAttribute(ClientContext.COOKIE_STORE,+cookieStore);
++++//+resourceUrl+-+is+url+which+leads+to+image
++++HttpGet+httpGet+=+new+HttpGet(resourceUrl);

++++try+{
++++++++HttpResponse+httpResponse+=+httpClient.execute(httpGet,+localContext);
++++++++return+httpResponse.getStatusLine().getStatusCode()+==+HttpStatus.SC_OK;
++++}+catch+(IOException+e)+{
++++++++return+false;
++++}
}

protected+BasicClientCookie+getSessionCookie()+{
++++Cookie+originalCookie+=+webDriver.manage().getCookieNamed(SESSION_COOKIE_NAME);

++++if+(originalCookie+==+null)+{
++++++++return+null;
++++}

++++//+just+build+new+apache-like+cookie+based+on+webDriver's+one
++++String+cookieName+=+originalCookie.getName();
++++String+cookieValue+=+originalCookie.getValue();
++++BasicClientCookie+resultCookie+=+new+BasicClientCookie(cookieName,+cookieValue);
++++resultCookie.setDomain(DOMAIN);
++++resultCookie.setExpiryDate(originalCookie.getExpiry());
++++resultCookie.setPath(COOKIE_PATH);
++++return+resultCookie;
}|code-block|syntax|javascript|829795|entityMap|0|LINK|mutability|MUTABLE|url|http://cyber-fall.blogspot.ru/2013/02/selenium-20-webdriver-best-practices_20.html^0|0|0|3|7|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@$F|X|G|Y|1|Z]]|A|$]]|$1|H|3|I|5|J|7|10|8|@]|9|@]|A|$K|L]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

Another mostly correct solution is to download it directly by simple HTTP request. 
You could use webDriver's user session, cause it stores cookies. 
In my <a href="http://cyber-fall.blogspot.ru/2013/02/selenium-20-webdriver-best-practices_20.html" rel="nofollow">example</a>, I'm just analyzing what status code it returns. If 200, then image exists and it is available for show or download. If you need to really download file itself - you could just get all image data from httpResponse entity (use it as simple input stream).

<pre><code>// just look at your cookie's content (e.g. using browser)
// and import these settings from it
private static final String SESSION_COOKIE_NAME = "JSESSIONID";
private static final String DOMAIN = "domain.here.com";
private static final String COOKIE_PATH = "/cookie/path/here";

protected boolean isResourceAvailableByUrl(String resourceUrl) {
 HttpClient httpClient = new DefaultHttpClient();
 HttpContext localContext = new BasicHttpContext();
 BasicCookieStore cookieStore = new BasicCookieStore();
 // apply jsessionid cookie if it exists
 cookieStore.addCookie(getSessionCookie());
 localContext.setAttribute(ClientContext.COOKIE_STORE, cookieStore);
 // resourceUrl - is url which leads to image
 HttpGet httpGet = new HttpGet(resourceUrl);

 try {
 HttpResponse httpResponse = httpClient.execute(httpGet, localContext);
 return httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK;
 } catch (IOException e) {
 return false;
 }
}

protected BasicClientCookie getSessionCookie() {
 Cookie originalCookie = webDriver.manage().getCookieNamed(SESSION_COOKIE_NAME);

 if (originalCookie == null) {
 return null;
 }

 // just build new apache-like cookie based on webDriver's one
 String cookieName = originalCookie.getName();
 String cookieValue = originalCookie.getValue();
 BasicClientCookie resultCookie = new BasicClientCookie(cookieName, cookieValue);
 resultCookie.setDomain(DOMAIN);
 resultCookie.setExpiryDate(originalCookie.getExpiry());
 resultCookie.setPath(COOKIE_PATH);
 return resultCookie;
}
</code></pre>

blocks|key|614561|text|这里的其他解决方案并不适用于所有浏览器，也不适用于所有网站，或者两者兼而有之。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|614562|这个解决方案应该更加健壮。它使用浏览器查看图像，调整浏览器大小以适应图像大小，截取屏幕截图，最后将浏览器大小调整回原始大小。|614563|Python：|614564|def+get_image(driver,+img_url):
++++'''Given+an+images+url,+return+a+binary+screenshot+of+it+in+png+format.'''
++++driver.get_url(img_url)

++++#+Get+the+dimensions+of+the+browser+and+image.
++++orig_h+=+driver.execute_script("return+window.outerHeight")
++++orig_w+=+driver.execute_script("return+window.outerWidth")
++++margin_h+=+orig_h+-+driver.execute_script("return+window.innerHeight")
++++margin_w+=+orig_w+-+driver.execute_script("return+window.innerWidth")
++++new_h+=+driver.execute_script('return+document.getElementsByTagName("img")[0].height')
++++new_w+=+driver.execute_script('return+document.getElementsByTagName("img")[0].width')

++++#+Resize+the+browser+window.
++++logging.info("Getting+Image:+orig+%25sX%25s,+marg+%25sX%25s,+img+%25sX%25s+-+%25s"%25(
++++++orig_w,+orig_h,+margin_w,+margin_h,+new_w,+new_h,+img_url))
++++driver.set_window_size(new_w+%2B+margin_w,+new_h+%2B+margin_h)

++++#+Get+the+image+by+taking+a+screenshot+of+the+page.
++++img_val+=+driver.get_screenshot_as_png()
++++#+Set+the+window+size+back+to+what+it+was.
++++driver.set_window_size(orig_w,+orig_h)

++++#+Go+back+to+where+we+started.
++++driver.back()
++++return+img_val|code-block|syntax|javascript|614565|这种解决方案的一个缺点是，如果图像非常小，浏览器不会调整那么小的大小，并且您可能会看到它周围的黑色边框。|614566|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|Q|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|R|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Other solutions here don't work across all browsers, don't work across all websites, or both.
This solution should be far more robust. It uses the browser to view the image, resizes the browser to fit the image size, takes a screenshot, and finally resizes the browser back to the original size.
<h2>Python:</h2>
<pre><code>def get_image(driver, img_url):
 '''Given an images url, return a binary screenshot of it in png format.'''
 driver.get_url(img_url)

 # Get the dimensions of the browser and image.
 orig_h = driver.execute_script(&quot;return window.outerHeight&quot;)
 orig_w = driver.execute_script(&quot;return window.outerWidth&quot;)
 margin_h = orig_h - driver.execute_script(&quot;return window.innerHeight&quot;)
 margin_w = orig_w - driver.execute_script(&quot;return window.innerWidth&quot;)
 new_h = driver.execute_script('return document.getElementsByTagName(&quot;img&quot;)[0].height')
 new_w = driver.execute_script('return document.getElementsByTagName(&quot;img&quot;)[0].width')

 # Resize the browser window.
 logging.info(&quot;Getting Image: orig %sX%s, marg %sX%s, img %sX%s - %s&quot;%(
 orig_w, orig_h, margin_w, margin_h, new_w, new_h, img_url))
 driver.set_window_size(new_w + margin_w, new_h + margin_h)

 # Get the image by taking a screenshot of the page.
 img_val = driver.get_screenshot_as_png()
 # Set the window size back to what it was.
 driver.set_window_size(orig_w, orig_h)

 # Go back to where we started.
 driver.back()
 return img_val
</code></pre>
One disadvantage of this solution is that if the image is very small, the browser will not resize that small, and you may get a black border around it.

blocks|key|614679|text|我更喜欢这样：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|614680|+WebElement+logo+=+driver.findElement(By.cssSelector(".image-logo"));
+String+logoSRC+=+logo.getAttribute("src");

+URL+imageURL+=+new+URL(logoSRC);
+BufferedImage+saveImage+=+ImageIO.read(imageURL);

+ImageIO.write(saveImage,+"png",+new+File("logo-image.png"));|code-block|syntax|javascript|614681|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I prefer like this:

<pre><code> WebElement logo = driver.findElement(By.cssSelector(".image-logo"));
 String logoSRC = logo.getAttribute("src");

 URL imageURL = new URL(logoSRC);
 BufferedImage saveImage = ImageIO.read(imageURL);

 ImageIO.write(saveImage, "png", new File("logo-image.png"));
</code></pre>

blocks|key|830016|text|使用selenium获取图像源|type|unstyled|depth|inlineStyleRanges|entityRanges|data|830017|elemImg.get_attribute('src')|code-block|syntax|javascript|830018|为此使用编程语言，对于python；请检查这个答案：How+to+save+an+image+locally+using+Python+whose+URL+address+I+already+know?|offset|length|830019|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/8286352/how-to-save-an-image-locally-using-python-whose-url-address-i-already-know^0|0|0|Q|23|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

use selenium for getting the image src

<pre><code>elemImg.get_attribute('src')
</code></pre>

use the programming language for this, for python;
check this answer:
<a href="https://stackoverflow.com/questions/8286352/how-to-save-an-image-locally-using-python-whose-url-address-i-already-know">How to save an image locally using Python whose URL address I already know?</a>

blocks|key|614833|text|这是一个javascript解决方案。这有点傻--而且我厌倦了用太多的请求访问源图像的服务器。谁能告诉我fetch()是否会访问浏览器的缓存？我不想向源服务器发送垃圾邮件。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|614834|它将FileReader()附加到窗口，获取图像并将其转换为base64，然后将该字符串标记到窗口上。|614835|然后，驱动程序可以返回该窗口变量。|614836|export+async+function+scrapePic(driver)+{
try+{
console.log("waiting+for+that+profile+piccah")
console.log(driver)

let+rootEl+=+await+driver.findElement(By.css('.your-root-element'));
let+imgEl+=+await+rootEl.findElement(By.css('img'))
await+driver.wait(until.elementIsVisible(imgEl,+10000));
console.log('profile+piccah+found')
let+img+=+await+imgEl.getAttribute('src')
//attach+reader+to+driver+window
await+driver.executeScript(`window.myFileReader+=+new+FileReader();`)
await+driver.executeScript(`
++window.myFileReader.onloadend+=+function()+{
++++window['profileImage']+=+this.result
++}
++fetch(+arguments[0]+).then(+res+=>+res.blob()+).then(+blob+=>+window.electronFileReader.readAsDataURL(blob)+)
++`,+img)
await+driver.sleep(5000)
let+img64+=+await+driver.executeScript(`return+window.profileImage`)
console.log(img64)


}+catch+(e)+{
console.log(e)
}+finally+{
return+img64
++}
}|code-block|syntax|javascript|614837|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|O|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|P|8|@]|9|@]|A|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

here is a javascript solution.
it's a tad silly -- and i'm weary of hitting the source image's server with too many requests. can someone tell me if the fetch() accesses the browser's cache? i don't want to spam the source server.

it appends a FileReader() to the window, fetches and converts the image to base64 and tags that string onto the window.

the driver can then return that window variable.

<pre><code>export async function scrapePic(driver) {
try {
console.log("waiting for that profile piccah")
console.log(driver)

let rootEl = await driver.findElement(By.css('.your-root-element'));
let imgEl = await rootEl.findElement(By.css('img'))
await driver.wait(until.elementIsVisible(imgEl, 10000));
console.log('profile piccah found')
let img = await imgEl.getAttribute('src')
//attach reader to driver window
await driver.executeScript(`window.myFileReader = new FileReader();`)
await driver.executeScript(`
 window.myFileReader.onloadend = function() {
 window['profileImage'] = this.result
 }
 fetch( arguments[0] ).then( res =&gt; res.blob() ).then( blob =&gt; window.electronFileReader.readAsDataURL(blob) )
 `, img)
await driver.sleep(5000)
let img64 = await driver.executeScript(`return window.profileImage`)
console.log(img64)


} catch (e) {
console.log(e)
} finally {
return img64
 }
}
</code></pre>

blocks|key|614861|text|适用于我：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|614862|#+open+the+image+in+a+new+tab
driver.execute_script('''window.open("'''+%2B+wanted_url+%2B+'''","_blank");''')
sleep(2)
driver.switch_to.window(driver.window_handles[1])
sleep(2)

#+make+screenshot
driver.save_screenshot("C://Folder/"+%2B+photo_name+%2B+".jpeg")
sleep(2)

#+close+the+new+tab
driver.execute_script('''window.close();''')
sleep(2)

#back+to+original+tab
driver.switch_to.window(driver.window_handles[0])|code-block|syntax|javascript|614863|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Works for me:

<pre><code># open the image in a new tab
driver.execute_script('''window.open("''' + wanted_url + '''","_blank");''')
sleep(2)
driver.switch_to.window(driver.window_handles[1])
sleep(2)

# make screenshot
driver.save_screenshot("C://Folder/" + photo_name + ".jpeg")
sleep(2)

# close the new tab
driver.execute_script('''window.close();''')
sleep(2)

#back to original tab
driver.switch_to.window(driver.window_handles[0])
</code></pre>

blocks|key|830191|text|对于我的用例，cookies和其他问题使得这里的其他方法不合适。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|830192|我最终使用XMLHttpRequest填充FileReader+(从How+to+convert+image+into+base64+string+using+javascript，然后使用Selenium的ExecuteAsyncScript调用它)(如Selenium+and+asynchronous+JavaScript+calls所示)。这让我可以得到一个可以直接解析的Data+URL。|offset|length|style|CODE|830193|下面是我用于获取数据URL的C#代码：|830194|public+string+ImageUrlToDataUrl(IWebDriver+driver,+string+imageUrl)
{
++var+js+=+new+StringBuilder();
++js.AppendLine("var+done+=+arguments[0];");+//+The+callback+from+ExecuteAsyncScript
++js.AppendLine(@"
++++function+toDataURL(url,+callback)+{
++++++var+xhr+=+new+XMLHttpRequest();
++++++xhr.onload+=+function()+{
++++++++var+reader+=+new+FileReader();
++++++++reader.onloadend+=+function()+{
++++++++++callback(reader.result);
++++++++}
++++++++reader.readAsDataURL(xhr.response);
++++++};
++++++xhr.open('GET',+url);
++++++xhr.responseType+=+'blob';
++++++xhr.send();
++++}");+//+XMLHttpRequest+->+FileReader+->+DataURL+conversion
++js.AppendLine("toDataURL('"+%2B+imageUrl+%2B+"',+done);");+//+Invoke+the+function

++var+executor+=+(IJavaScriptExecutor)+driver;
++var+dataUrl+=+executor.ExecuteAsyncScript(js.ToString())+as+string;
++return+dataUrl;
}|code-block|syntax|javascript|830195|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/6150289/how-to-convert-image-into-base64-string-using-javascript|1|https://stackoverflow.com/questions/31208818/selenium-and-asynchronous-javascript-calls|2|https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs^0|0|2W|I|Y|1K|0|3K|16|1|5A|8|2|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|11|8|@$D|12|E|13|F|G]]|9|@$D|14|E|15|1|16]|$D|17|E|18|1|19]|$D|1A|E|1B|1|1C]]|A|$]]|$1|H|3|I|5|6|7|1D|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|1E|8|@]|9|@]|A|$M|N]]|$1|O|3|-4|5|6|7|1F|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]|W|$5|R|S|T|A|$U|X]]|Y|$5|R|S|T|A|$U|Z]]]]

For my use case there were cookies and other issues that made the other approaches here unsuitable.

I ended up using an XMLHttpRequest to populate a FileReader (from <a href="https://stackoverflow.com/questions/6150289/how-to-convert-image-into-base64-string-using-javascript">How to convert image into base64 string using javascript</a>, and then calling that using Selenium's <code>ExecuteAsyncScript</code> (as shown in <a href="https://stackoverflow.com/questions/31208818/selenium-and-asynchronous-javascript-calls">Selenium and asynchronous JavaScript calls</a>). This allowed me to get a <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs" rel="nofollow noreferrer">Data URL</a> which was straight forward to parse.

Here's my C# code for getting the Data URL:

<pre class="lang-cs prettyprint-override"><code>public string ImageUrlToDataUrl(IWebDriver driver, string imageUrl)
{
 var js = new StringBuilder();
 js.AppendLine("var done = arguments[0];"); // The callback from ExecuteAsyncScript
 js.AppendLine(@"
 function toDataURL(url, callback) {
 var xhr = new XMLHttpRequest();
 xhr.onload = function() {
 var reader = new FileReader();
 reader.onloadend = function() {
 callback(reader.result);
 }
 reader.readAsDataURL(xhr.response);
 };
 xhr.open('GET', url);
 xhr.responseType = 'blob';
 xhr.send();
 }"); // XMLHttpRequest -&gt; FileReader -&gt; DataURL conversion
 js.AppendLine("toDataURL('" + imageUrl + "', done);"); // Invoke the function

 var executor = (IJavaScriptExecutor) driver;
 var dataUrl = executor.ExecuteAsyncScript(js.ToString()) as string;
 return dataUrl;
}
</code></pre>

blocks|key|614906|text|请尝试以下操作|type|unstyled|depth|inlineStyleRanges|entityRanges|data|614907|JavascriptExecutor+js+=+(JavascriptExecutor)+driver;++++++++++++++++++++++++++++++
String+base64string+=+(String)+js.executeScript("var+c+=+document.createElement('canvas');"
+++++++++++++++++++++++%2B+"+var+ctx+=+c.getContext('2d');"
+++++++++++++++++++++++%2B+"var+img+=+document.getElementsByTagName('img')[0];"
+++++++++++++++++++++++%2B+"c.height=img.naturalHeight;"
+++++++++++++++++++++++%2B+"c.width=img.naturalWidth;"
+++++++++++++++++++++++%2B+"ctx.drawImage(img,+0,+0,img.naturalWidth,+img.naturalHeight);"
+++++++++++++++++++++++%2B+"var+base64String+=+c.toDataURL();"
+++++++++++++++++++++++%2B+"return+base64String;");
String[]+base64Array+=+base64string.split(",");

String+base64+=+base64Array[base64Array.length+-+1];

byte[]+data+=+Base64.decode(base64);

ByteArrayInputStream+memstream+=+new+ByteArrayInputStream(data);
BufferedImage+saveImage+=+ImageIO.read(memstream);

ImageIO.write(saveImage,+"png",+new+File("path"));|code-block|syntax|javascript|614908|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

try the following

<pre><code>JavascriptExecutor js = (JavascriptExecutor) driver; 
String base64string = (String) js.executeScript("var c = document.createElement('canvas');"
 + " var ctx = c.getContext('2d');"
 + "var img = document.getElementsByTagName('img')[0];"
 + "c.height=img.naturalHeight;"
 + "c.width=img.naturalWidth;"
 + "ctx.drawImage(img, 0, 0,img.naturalWidth, img.naturalHeight);"
 + "var base64String = c.toDataURL();"
 + "return base64String;");
String[] base64Array = base64string.split(",");

String base64 = base64Array[base64Array.length - 1];

byte[] data = Base64.decode(base64);

ByteArrayInputStream memstream = new ByteArrayInputStream(data);
BufferedImage saveImage = ImageIO.read(memstream);

ImageIO.write(saveImage, "png", new File("path"));
</code></pre>

blocks|key|614922|text|我发现避免两次下载图像的唯一方法是使用Chrome+DevTools协议查看器。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|614923|在Python中，这提供了：|614924|import+base64
import+pychrome
def+save_image(file_content,+file_name):
++++try:
+++++++file_content=base64.b64decode(file_content)
+++++++with+open("C:\\Crawler\\temp\\"+%2B+file_name,"wb")+as+f:
++++++++++++f.write(file_content)
++++except+Exception+as+e:
+++++++print(str(e))

def+response_received(requestId,+loaderId,+timestamp,+type,+response,+frameId):
++++if+type+==+'Image':
++++++++url+=+response.get('url')
++++++++print(f"Image+loaded:+{url}")
++++++++response_body+=+tab.Network.getResponseBody(requestId=requestId)
++++++++file_name+=+url.split('/')[-1].split('?')[0]
++++++++if+file_name:
++++++++++++save_image(response_body['body'],+file_name)


tab.Network.responseReceived+=+response_received

#+start+the+tab+
tab.start()

#+call+method
tab.Network.enable()

#+get+request+to+target+the+site+selenium+
driver.get("https://www.realtor.com/ads/forsale/TMAI112283AAAA")

#+wait+for+loading
tab.wait(50)|code-block|syntax|javascript|614925|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

The only way I found to avoid downloading the image twice is to use the Chrome DevTools Protocol Viewer.

In Python, this gives:

<pre><code>import base64
import pychrome
def save_image(file_content, file_name):
 try:
 file_content=base64.b64decode(file_content)
 with open("C:\\Crawler\\temp\\" + file_name,"wb") as f:
 f.write(file_content)
 except Exception as e:
 print(str(e))

def response_received(requestId, loaderId, timestamp, type, response, frameId):
 if type == 'Image':
 url = response.get('url')
 print(f"Image loaded: {url}")
 response_body = tab.Network.getResponseBody(requestId=requestId)
 file_name = url.split('/')[-1].split('?')[0]
 if file_name:
 save_image(response_body['body'], file_name)


tab.Network.responseReceived = response_received

# start the tab 
tab.start()

# call method
tab.Network.enable()

# get request to target the site selenium 
driver.get("https://www.realtor.com/ads/forsale/TMAI112283AAAA")

# wait for loading
tab.wait(50)
</code></pre>

blocks|key|830273|text|虽然@abory021+JS代码在语法上是正确的，但我无法运行代码。(使用Chrome+V83.xx)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|830274|然而，下面的代码是有效的(Java)：|830275|++++String+url+=+"/your-url-goes.here.jpg";
++++String+imageData+=+(String)+((JavascriptExecutor)+driver).executeAsyncScript(
++++++++++++"var+callback+=+arguments[0];"+%2B+//+The+callback+from+ExecuteAsyncScript
++++++++++++++++++++"var+reader;"+%2B
++++++++++++++++++++"var+xhr+=+new+XMLHttpRequest();"+%2B
++++++++++++++++++++"xhr.onreadystatechange+=+function()+{"+%2B
++++++++++++++++++++"++if+(xhr.readyState+==+4)+{"+%2B
++++++++++++++++++++++++"var+reader+=+new+FileReader();"+%2B
++++++++++++++++++++++++"reader.readAsDataURL(xhr.response);"+%2B
++++++++++++++++++++++++"reader.onloadend+=+function()+{"+%2B
++++++++++++++++++++++++"++++callback(reader.result);"+%2B
++++++++++++++++++++++++"}"+%2B
++++++++++++++++++++"++}"+%2B
++++++++++++++++++++"};"+%2B
++++++++++++++++++++"xhr.open('GET',+'"+%2B+url+%2B+"',+true);"+%2B
++++++++++++++++++++"xhr.responseType+=+'blob';"+%2B
++++++++++++++++++++"xhr.send();");

++++String+base64Data+=+imageData.split(",")[1];

++++byte[]+decodedBytes+=+Base64.getDecoder().decode(base64Data);
++++try+(OutputStream+stream+=+new+FileOutputStream("c:\\dev\\tmp\\output.jpg"))+{
++++++++stream.write(decodedBytes);
++++}+catch+(IOException+e)+{
++++++++e.printStackTrace();
++++}|code-block|syntax|javascript|830276|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Although @aboy021 JS code is syntactly correct I couldn't the code running. (using Chrome V83.xx)
However this code worked (Java):
<pre><code> String url = &quot;/your-url-goes.here.jpg&quot;;
 String imageData = (String) ((JavascriptExecutor) driver).executeAsyncScript(
 &quot;var callback = arguments[0];&quot; + // The callback from ExecuteAsyncScript
 &quot;var reader;&quot; +
 &quot;var xhr = new XMLHttpRequest();&quot; +
 &quot;xhr.onreadystatechange = function() {&quot; +
 &quot; if (xhr.readyState == 4) {&quot; +
 &quot;var reader = new FileReader();&quot; +
 &quot;reader.readAsDataURL(xhr.response);&quot; +
 &quot;reader.onloadend = function() {&quot; +
 &quot; callback(reader.result);&quot; +
 &quot;}&quot; +
 &quot; }&quot; +
 &quot;};&quot; +
 &quot;xhr.open('GET', '&quot; + url + &quot;', true);&quot; +
 &quot;xhr.responseType = 'blob';&quot; +
 &quot;xhr.send();&quot;);

 String base64Data = imageData.split(&quot;,&quot;)[1];

 byte[] decodedBytes = Base64.getDecoder().decode(base64Data);
 try (OutputStream stream = new FileOutputStream(&quot;c:\\dev\\tmp\\output.jpg&quot;)) {
 stream.write(decodedBytes);
 } catch (IOException e) {
 e.printStackTrace();
 }
</code></pre>

I was wondering, how can one use selenium/webdriver to download an image for a page. Assuming that the user session is required to download the image hence having pure URL is not helpful. Any sample code is highly appreciated.

How to download an image using Selenium (any version)?

我想知道，如何使用selenium/webdriver为页面下载图像。假设需要用户会话来下载图像，因此使用纯URL没有什么帮助。任何示例代码都是高度赞赏的。

问如何使用Selenium (任意版本)下载镜像？
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