diff --git a/app.apk b/app.apk
deleted file mode 100644
index 3515ff2..0000000
Binary files a/app.apk and /dev/null differ
diff --git a/main/AndroidManifest.xml b/main/AndroidManifest.xml
index 7a871dd..e12092e 100644
--- a/main/AndroidManifest.xml
+++ b/main/AndroidManifest.xml
@@ -2,7 +2,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           package="com.hty.browser"
           android:versionCode="4"
-          android:versionName="4.19">
+          android:versionName="4.21">
 
     <application
         android:icon="@drawable/ic_launcher"
diff --git a/main/assets/about.htm b/main/assets/about.htm
index 86d743d..512cddf 100644
--- a/main/assets/about.htm
+++ b/main/assets/about.htm
@@ -23,6 +23,8 @@ p { text-indent:2em; }
 <p><a href="https://stackoverflow.com/questions/3462582/display-the-android-webviews-favicon" target="_blank">获取网页图标</a></p>
 <p><a href="https://www.jianshu.com/p/c9a18050a249" target="_blank">字符串转Bitmap</a></p>
 <h3>更新日志：</h3>
+<h3>V4.21 (2021-11-21)</h3><ol><li>收藏夹增加在新窗口打开。</li><li>简化视频截图代码。</li></ol>
+<h3>V4.20 (2021-08-10)</h3><ol><li><a href="https://blog.csdn.net/woaixiaozhe/article/details/7575976" _target="_blank">双击返回键退出</a></li></ol>
 <h3>V4.19 (2021-06-27)</h3><ol><li>增加请求电脑版网页。</li></ol>
 <h3>V4.18 (2021-06-01)</h3><ol><li>增加动态权限请求。</li></ol>
 <h3>V4.17 (2021-03-02)</h3><ol><li>允许HTTPS、HTTP混合内容，解决微信网页视频无法播放的问题。</li></ol>
diff --git a/main/java/com/hty/browser/FavoriteActivity.java b/main/java/com/hty/browser/FavoriteActivity.java
index 7a20853..54cb195 100644
--- a/main/java/com/hty/browser/FavoriteActivity.java
+++ b/main/java/com/hty/browser/FavoriteActivity.java
@@ -76,11 +76,12 @@ public class FavoriteActivity extends Activity {
             public void onCreateContextMenu(ContextMenu menu, View view, ContextMenuInfo menuInfo) {
                 AdapterContextMenuInfo info = (AdapterContextMenuInfo) menuInfo;
                 String title = ((TextView) info.targetView.findViewById(R.id.title)).getText().toString();
+                menu.setHeaderIcon(R.drawable.link);
                 menu.setHeaderTitle(title);
-                menu.add(0, 0, 0, "复制链接");
-                menu.add(0, 1, 1, "删除");
-                menu.add(0, 2, 2, "修改");
-                menu.add(0, 3, 3, "分享");
+                String[] sm = { "在新窗口中打开", "复制链接", "分享", "修改", "删除" };
+                for (int i=0; i<sm.length; i++) {
+                    menu.add(0, i, i, sm[i]);
+                }
             }
         });
         listView.setOnTouchListener(new View.OnTouchListener() {
@@ -93,8 +94,6 @@ public class FavoriteActivity extends Activity {
         search(editText.getText().toString());
     }
 
-
-
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         String[] sm = { "导出HTML", "导出CSV" };
@@ -140,24 +139,31 @@ public class FavoriteActivity extends Activity {
     @Override
     public boolean onContextItemSelected(MenuItem item) {
         AdapterContextMenuInfo menuInfo = (AdapterContextMenuInfo) item.getMenuInfo();
-        position = menuInfo.position;
+        position = listView.getFirstVisiblePosition();
+        final String sid = ((TextView) menuInfo.targetView.findViewById(R.id.id)).getText().toString();
+        final String stitle = ((TextView) menuInfo.targetView.findViewById(R.id.title)).getText().toString();
+        final String surl = ((TextView) menuInfo.targetView.findViewById(R.id.website)).getText().toString();
         switch (item.getItemId()) {
             case 0:
-                ClipboardManager cm = (ClipboardManager) getSystemService(CLIPBOARD_SERVICE);
-                String url = ((TextView) menuInfo.targetView.findViewById(R.id.website)).getText().toString();
-                cm.setPrimaryClip(ClipData.newPlainText("link", url));
-                Toast.makeText(getApplicationContext(), "链接已复制", Toast.LENGTH_SHORT).show();
+                Intent intent = new Intent(FavoriteActivity.this, MainActivity.class);
+                intent.putExtra("url", surl);
+                intent.putExtra("newWindow", true);
+                setResult(RESULT_OK, intent);
+                finish();
                 break;
             case 1:
-                int id = Integer.parseInt(((TextView) menuInfo.targetView.findViewById(R.id.id)).getText().toString());
-                DBHelper helper = new DBHelper(getApplicationContext());
-                helper.del(id);
-                search(editText.getText().toString());
+                ClipboardManager CM = (ClipboardManager) getSystemService(CLIPBOARD_SERVICE);
+                CM.setPrimaryClip(ClipData.newPlainText("link", surl));
+                Toast.makeText(getApplicationContext(), "链接已复制", Toast.LENGTH_SHORT).show();
                 break;
             case 2:
-                final String sid = ((TextView) menuInfo.targetView.findViewById(R.id.id)).getText().toString();
-                final String stitle = ((TextView) menuInfo.targetView.findViewById(R.id.title)).getText().toString();
-                final String surl = ((TextView) menuInfo.targetView.findViewById(R.id.website)).getText().toString();
+                intent = new Intent();
+                intent.setAction(Intent.ACTION_SEND);
+                intent.putExtra(Intent.EXTRA_TEXT, stitle + "\n" + surl);
+                intent.setType("text/plain");
+                startActivity(Intent.createChooser(intent, "分享"));
+                break;
+            case 3:
                 LinearLayout layout = new LinearLayout(FavoriteActivity.this);
                 layout.setOrientation(LinearLayout.VERTICAL);
                 final EditText ET_title = new EditText(FavoriteActivity.this);
@@ -236,12 +242,11 @@ public class FavoriteActivity extends Activity {
                 });
                 builder.create().show();
                 break;
-            case 3:
-                Intent intent = new Intent();
-                intent.setAction(Intent.ACTION_SEND);
-                intent.putExtra(Intent.EXTRA_TEXT, ((TextView) menuInfo.targetView.findViewById(R.id.title)).getText().toString() + "\n" + ((TextView) menuInfo.targetView.findViewById(R.id.website)).getText().toString());
-                intent.setType("text/plain");
-                startActivity(Intent.createChooser(intent, "分享"));
+            case 4:
+                int id = Integer.parseInt(((TextView) menuInfo.targetView.findViewById(R.id.id)).getText().toString());
+                DBHelper helper = new DBHelper(getApplicationContext());
+                helper.del(id);
+                search(editText.getText().toString());
                 break;
         }
         return true;
diff --git a/main/java/com/hty/browser/MainActivity.java b/main/java/com/hty/browser/MainActivity.java
index 3144ae8..62c1a28 100644
--- a/main/java/com/hty/browser/MainActivity.java
+++ b/main/java/com/hty/browser/MainActivity.java
@@ -20,6 +20,8 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Date;
 import java.util.List;
+import java.util.Timer;
+import java.util.TimerTask;
 
 import android.Manifest;
 import android.app.Activity;
@@ -125,6 +127,7 @@ public class MainActivity extends Activity {
             Manifest.permission.READ_EXTERNAL_STORAGE,
             Manifest.permission.WRITE_EXTERNAL_STORAGE };
     private static int REQUEST_PERMISSION_CODE = 1;
+    Boolean isExit = false;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -452,8 +455,7 @@ public class MainActivity extends Activity {
                 if (list_webView.get(currentPage).canGoBack()) {
                     list_webView.get(currentPage).goBack();
                 } else {
-                    // moveTaskToBack(false);
-                    // MenuDialog();
+                    exitBy2Click();
                 }
             }
             return true;
@@ -511,7 +513,10 @@ public class MainActivity extends Activity {
         }
         if (requestCode == 0) {
             if (intent != null)
-                list_webView.get(currentPage).loadUrl(intent.getStringExtra("url"));
+                if (intent.getBooleanExtra("newWindow", false))
+                    newWindow(intent.getStringExtra("url"));
+                else
+                    list_webView.get(currentPage).loadUrl(intent.getStringExtra("url"));
         }
         if (requestCode == FILECHOOSER_DOWNLOAD_PATH) {
             if (resultCode == Activity.RESULT_OK) { //是否选择，没选择就不会继续
@@ -651,9 +656,9 @@ public class MainActivity extends Activity {
                         break;
                     case 1:
                         list_webView.remove(currentPage);
-                        if(list_webView.size() == 0){
+                        if (list_webView.size() == 0) {
                             newWindow(sharedPreferences.getString("homepage","http://www.baidu.com"));
-                        }else{
+                        } else {
                             currentPage--;
                             if (currentPage < 0) currentPage = 0;
                             button_page.setText(currentPage + 1 + "");
@@ -743,6 +748,7 @@ public class MainActivity extends Activity {
                                     field = dialog.getClass().getSuperclass().getDeclaredField("mShowing");
                                     field.setAccessible(true);//设置该属性可以访问
                                 } catch (Exception ex) {
+
                                 }
                                 try {
                                     field.set(dialog, true);
@@ -780,7 +786,7 @@ public class MainActivity extends Activity {
                             @Override
                             public void onReceiveValue(String value) {
                                 Log.e(Thread.currentThread().getStackTrace()[2] + "", value);
-                                if(!"null".equals(value)){
+                                if(!value.equals("null")){
                                     //字符串转Bitmap，https://www.jianshu.com/p/c9a18050a249
                                     byte[] bitmapArray = Base64.decode(value.split(",")[1], Base64.DEFAULT);
                                     final Bitmap bitmap = BitmapFactory.decodeByteArray(bitmapArray, 0, bitmapArray.length);
@@ -795,35 +801,10 @@ public class MainActivity extends Activity {
                                     builder.setPositiveButton("保存", new DialogInterface.OnClickListener() {
                                         @Override
                                         public void onClick(DialogInterface dialog, int which) {
-                                            String dir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM).toString() + File.separator + "Screenshots";
-                                            File temp = new File(dir);  // 如果文件夹不存在则创建
-                                            if (!temp.exists()) {
-                                                temp.mkdir();
-                                            }
                                             Date date = new Date();
                                             SimpleDateFormat SDF = new SimpleDateFormat("yyyyMMddHHmmss");
                                             String stime = SDF.format(date);
-                                            String path = dir + stime + ".jpg";
-                                            File file = new File(path);
-                                            BufferedOutputStream BOS = null;
-                                            try {
-                                                BOS = new BufferedOutputStream(new FileOutputStream(file));
-                                            }catch (FileNotFoundException e){
-                                                Log.e(Thread.currentThread().getStackTrace()[2] + "", "" + e);
-                                            }
-                                            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, BOS);
-                                            try {
-                                                BOS.flush();
-                                            } catch (IOException e) {
-                                                e.printStackTrace();
-                                            }
-                                            try {
-                                                BOS.close();
-                                            }catch (IOException e) {
-                                                e.printStackTrace();
-                                            }
-                                            Toast.makeText(getApplicationContext(), "保存到："+path, Toast.LENGTH_SHORT).show();
-                                            MediaScannerConnection.scanFile(MainActivity.this, new String[] { path }, null, null);
+                                            Uri.parse(MediaStore.Images.Media.insertImage(getApplicationContext().getContentResolver(), bitmap, stime, "海天鹰浏览器视频截图"));
                                         }
                                     });
                                     builder.setNegativeButton("关闭", new DialogInterface.OnClickListener() {
@@ -832,7 +813,7 @@ public class MainActivity extends Activity {
                                         }
                                     });
                                     builder.create().show();
-                                }else{
+                                } else {
                                     Toast.makeText(getApplicationContext(), "请先播放视频或把视频独立播放", Toast.LENGTH_SHORT).show();
                                 }
                             }
@@ -846,16 +827,16 @@ public class MainActivity extends Activity {
                             @Override
                             public void onReceiveValue(String value) {
                                 Log.e(Thread.currentThread().getStackTrace()[2] + "", "" + value);
-                                if(!"null".equals(value)) {
+                                if(!value.equals("null")) {
                                     try {
                                         Intent intent1 = new Intent(Intent.ACTION_VIEW);
                                         String type = "video/*";
                                         Uri uri = Uri.parse(value);
                                         intent1.setDataAndType(uri, type);
                                         startActivity(intent1);
-                                    } catch (ActivityNotFoundException e) {
-                                        Log.e(Thread.currentThread().getStackTrace()[2] + "", "" + e);
-                                        Toast.makeText(getApplicationContext(), "系统默认播放器不能打开视频", Toast.LENGTH_SHORT).show();
+                                    } catch (Exception e) {
+                                        Log.e(Thread.currentThread().getStackTrace()[2] + "", e.toString());
+                                        Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_SHORT).show();
                                     }
                                 }
                             }
@@ -939,7 +920,7 @@ public class MainActivity extends Activity {
                                                 }
                                             }
                                             String content="";
-                                            for(int i=0; i<rulelist.size(); i++){
+                                            for (int i=0; i<rulelist.size(); i++) {
                                                 content += rulelist.get(i) + "\n";
                                             }
                                             FileOutputStream outStream = null;
@@ -947,10 +928,8 @@ public class MainActivity extends Activity {
                                                 outStream = MainActivity.this.openFileOutput("blockrules", Context.MODE_PRIVATE);
                                                 outStream.write((content).getBytes());
                                                 outStream.close();
-                                            } catch (FileNotFoundException e) {
-                                                e.printStackTrace();
-                                            }catch (IOException e) {
-                                                e.printStackTrace();
+                                            } catch (Exception e) {
+                                                Log.e(Thread.currentThread().getStackTrace()[2] + "", e.toString());
                                             }
                                             dialogRule.dismiss();
                                             ADBlock();
@@ -974,10 +953,8 @@ public class MainActivity extends Activity {
             outStream.write((content+"\n").getBytes());
             outStream.close();
             ADBlock();
-        } catch (FileNotFoundException e) {
-            e.printStackTrace();
-        }catch (IOException e) {
-            e.printStackTrace();
+        } catch (Exception e) {
+            Log.e(Thread.currentThread().getStackTrace()[2] + "", e.toString());
         }
     }
 
@@ -1461,7 +1438,7 @@ public class MainActivity extends Activity {
         //Log.e(Thread.currentThread().getStackTrace()[2] + "", "onNewIntent(" + getIntent() + ")");
         super.onNewIntent(intent);
         setIntent(intent);
-        if(getIntent().getDataString() != null) {
+        if (getIntent().getDataString() != null) {
             urln = getIntent().getDataString();
             Log.e(Thread.currentThread().getStackTrace()[2] + "", "onNewIntent(" + urln + ")");
             newWindow(urln);
@@ -1556,8 +1533,7 @@ public class MainActivity extends Activity {
             try {
                 urlcon = (HttpURLConnection) url.openConnection();
                 fileLength = urlcon.getContentLength();
-
-            } catch (IOException e) {
+            } catch (Exception e) {
                 e.printStackTrace();
             }
             Message message = Message.obtain();
@@ -1567,4 +1543,22 @@ public class MainActivity extends Activity {
         }
     }
 
+    //双击返回键退出：https://blog.csdn.net/woaixiaozhe/article/details/7575976
+    void exitBy2Click() {
+        Timer timer;
+        if (isExit == false) {
+            isExit = true;
+            Toast.makeText(this, "再按一次退出", Toast.LENGTH_SHORT).show();
+            timer = new Timer();
+            timer.schedule(new TimerTask() {
+                @Override
+                public void run() {
+                    isExit = false;
+                }
+            }, 2000);
+        } else {
+            finish();
+        }
+    }
+
 }
\ No newline at end of file
diff --git a/main/res/layout/activity_favorite.xml b/main/res/layout/activity_favorite.xml
index 577a027..aa57944 100644
--- a/main/res/layout/activity_favorite.xml
+++ b/main/res/layout/activity_favorite.xml
@@ -31,7 +31,7 @@
         <ImageButton
             android:id="@+id/imageButton_clear"
             android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
+            android:layout_height="match_parent"
             android:layout_weight="1"
             android:background="#ffffff"
             android:paddingLeft="-15dp"
diff --git a/version b/version
index 1ae015e..dab0b6a 100644
--- a/version
+++ b/version
@@ -1 +1 @@
-4.19
\ No newline at end of file
+4.21
\ No newline at end of file