Pau*_*Jan 43
从webview获取纯文本内容相当困难.基本上,Android类不提供它,但javascript确实如此,Android为javascript提供了一种将信息传递回代码的方法.
在进入细节之前,请注意,如果您的html结构很简单,那么手动解析数据可能会更好.
也就是说,这就是你做的:
为了澄清,我将在下面发布一个工作(但非常粗略)的代码示例.它在顶部显示webview,在底部显示带有基于文本的内容的textview.
package test.android.webview;
import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.TextView;
public class WebviewTest2Activity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
WebView webView = (WebView) findViewById(R.id.webView);
TextView contentView = (TextView) findViewById(R.id.contentView);
/* An instance of this class will be registered as a JavaScript interface */
class MyJavaScriptInterface
{
private TextView contentView;
public MyJavaScriptInterface(TextView aContentView)
{
contentView = aContentView;
}
@SuppressWarnings("unused")
public void processContent(String aContent)
{
final String content = aContent;
contentView.post(new Runnable()
{
public void run()
{
contentView.setText(content);
}
});
}
}
webView.getSettings().setJavaScriptEnabled(true);
webView.addJavascriptInterface(new MyJavaScriptInterface(contentView), "INTERFACE");
webView.setWebViewClient(new WebViewClient() {
@Override
public void onPageFinished(WebView view, String url)
{
view.loadUrl("javascript:window.INTERFACE.processContent(document.getElementsByTagName('body')[0].innerText);");
}
});
webView.loadUrl("http://shinyhammer.blogspot.com");
}
}
使用以下main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<WebView
android:id="@+id/webView"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:layout_weight="0.5" />
<TextView
android:id="@+id/contentView"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:layout_weight="0.5" />
</LinearLayout>
wvbrowser.evaluateJavascript(
"(function() { return ('<html>'+document.getElementsByTagName('html')[0].innerHTML+'</html>'); })();",
new ValueCallback<String>() {
@Override
public void onReceiveValue(String html) {
Log.d("HTML", html);
// code here
}
});
小智 5
上面提供的解决方案使用innerText 属性提供文本，该属性将返回webView 中的所有文本。我在下面提出的解决方案将帮助您从屏幕上 webView 的可见部分提取文本。
步骤1：需要javaScript的帮助，因此首先启用javascript。
webView.addJavascriptInterface(new IJavascriptHandler(getActivity().getApplicationContext()), "Android"); //if your class extends a Fragment class
或者
view.addJavascriptInterface(new IJavascriptHandler(this), "Android"); //if your class extends Activity.
第 2 步：创建一个 javaInterface 内部类。
final class IJavascriptHandler {
Context mContext;
IJavascriptHandler(Context c) {
mContext = c;
}
//API 17 and higher required you to add @JavascriptInterface as mandatory before your method.
@JavascriptInterface
public void processContent(String aContent)
{
//this method will be called from within the javascript method that you will write.
final String content = aContent;
Log.e("The content of the current page is ",content);
}
}
第 3 步：现在您必须添加 javascript 方法。您将方法编写为字符串，然后加载它。该方法根据提供给它的参数返回文本。所以，你需要2个字符串。一个将加载 javascript 方法，另一个将调用它。
加载javascript方法的方法。
String javaScriptToExtractText = "function getAllTextInColumn(left,top,width,height){"
+ "if(document.caretRangeFromPoint){"
+ "var caretRangeStart = document.caretRangeFromPoint(left, top);"
+ "var caretRangeEnd = document.caretRangeFromPoint(left+width-1, top+height-1);"
+ "} else {"
+ "return null;"
+ "}"
+ "if(caretRangeStart == null || caretRangeEnd == null) return null;"
+ "var range = document.createRange();"
+ "range.setStart(caretRangeStart.startContainer, caretRangeStart.startOffset);"
+ "range.setEnd(caretRangeEnd.endContainer, caretRangeEnd.endOffset);"
+ "return range.toString();};";
调用上述函数的方法。
String javaScriptFunctionCall = "getAllTextInColumn(0,0,100,100)";
//I've provided the parameter here as 0,0 i.e the left and top offset and then 100, 100 as width and height. So, it'll extract the text present in that area.
第 4 步：现在，您需要加载上述 2 个 javascript。
webView.loadUrl("javascript:"+ javaScriptToExtractText);
//this will load the method.
view.loadUrl("javascript:window.Android.processContent("+javaScriptFunctionCall+");");
//this will call the loaded javascript method.
享受。