Android实现在webview中长按图片弹出菜单保存图片

Android实现在webview中长按图片弹出菜单保存图片

在项目中遇到一个保存webview中二维码图片的问题,做个笔记。
效果如图: 这里写图片描述
用到webview的三个方法:

  • getHitTestResult()——Gets a HitTestResult based on the current cursor node
  • getType()——Gets the type of the hit test result(获取所选中目标的类型,可以是图片,超链接,邮件,电话等等)
  • getExtra()——Gets additional type-dependant information about the result(获取额外的信息,例如图片的地址)

1. 第一步:给webview添加长按监听

_mWebview.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                }
            });

2. 第二步:通过webview的getHitTestResult()方法获取HitTestResult 对象

(1)通过getType()获取类型,通过类型判断是否是图片

WebView.HitTestResult result = ((WebView) v).getHitTestResult();
int type = result.getType();
  • 1
  • 2

type有这几种类型

WebView.HitTestResult.UNKNOWN_TYPE    未知类型
WebView.HitTestResult.PHONE_TYPE    电话类型
WebView.HitTestResult.EMAIL_TYPE    电子邮件类型
WebView.HitTestResult.GEO_TYPE    地图类型
WebView.HitTestResult.SRC_ANCHOR_TYPE    超链接类型
WebView.HitTestResult.SRC_IMAGE_ANCHOR_TYPE    带有链接的图片类型
WebView.HitTestResult.IMAGE_TYPE    单纯的图片类型
WebView.HitTestResult.EDIT_TEXT_TYPE    选中的文字类型

(2)通过getExtra()获取额外信息,图片这里就是图片地址

String imgurl = result.getExtra();
  •  

通过判断类型来做不同的显示效果,在这里我只对图片处理,长按图片弹出一个PopWindow,效果自己写。

3. 第三步:通过获取的图片地址下载图片

最后把所有代码整理一下:

自定义PopWindow——ItemLongClickedPopWindow.java

public class ItemLongClickedPopWindow extends PopupWindow {
    /**
     * 书签条目弹出菜单 * @value * {@value} *
     */
    public static final int FAVORITES_ITEM_POPUPWINDOW = 0;
    /**
     * 书签页面弹出菜单 * @value * {@value} *
     */
    public static final int FAVORITES_VIEW_POPUPWINDOW = 1;
    /**
     * 历史条目弹出菜单 * @value * {@value} *
     */
    public static final int HISTORY_ITEM_POPUPWINDOW = 3;
    /**
     * 历史页面弹出菜单 * @value * {@value} *
     */
    public static final int HISTORY_VIEW_POPUPWINDOW = 4;
    /**
     * 图片项目弹出菜单 * @value * {@value} *
     */
    public static final int IMAGE_VIEW_POPUPWINDOW = 5;
    /**
     * 超链接项目弹出菜单 * @value * {@value} *
     */
    public static final int ACHOR_VIEW_POPUPWINDOW = 6;
    private LayoutInflater itemLongClickedPopWindowInflater;
    private View itemLongClickedPopWindowView;
    private Context context;
    private int type;

    /**
     * 构造函数 * @param context 上下文 * @param width 宽度 * @param height 高度 *
     */
    public ItemLongClickedPopWindow(Context context, int type, int width, int height) {
        super(context);
        this.context = context;
        this.type = type;
        //创建
        this.initTab();
        //设置默认选项
        setWidth(width);
        setHeight(height);
        setContentView(this.itemLongClickedPopWindowView);
        setOutsideTouchable(true);
        setFocusable(true);
    }

    //实例化
    private void initTab() {
        this.itemLongClickedPopWindowInflater = LayoutInflater.from(this.context);
        switch (type) {
//            case FAVORITES_ITEM_POPUPWINDOW:
//                this.itemLongClickedPopWindowView = this.itemLongClickedPopWindowInflater.inflate(R.layout.list_item_longclicked_favorites, null);
//                break;
//            case FAVORITES_VIEW_POPUPWINDOW: //对于书签内容弹出菜单,未作处理
//                break;
//            case HISTORY_ITEM_POPUPWINDOW:
//                this.itemLongClickedPopWindowView = this.itemLongClickedPopWindowInflater.inflate(R.layout.list_item_longclicked_history, null);
//                break;
//            case HISTORY_VIEW_POPUPWINDOW: //对于历史内容弹出菜单,未作处理
//                break;
//            case ACHOR_VIEW_POPUPWINDOW: //超链接
//               break;
            case IMAGE_VIEW_POPUPWINDOW: //图片
                this.itemLongClickedPopWindowView = this.itemLongClickedPopWindowInflater.inflate(R.layout.list_item_longclicked_img, null);
                break;
        }
    }

    public View getView(int id) {
        return this.itemLongClickedPopWindowView.findViewById(id);
    }
}

PopWindow的布局文件——list_item_longclicked_img.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="5dp"
    android:orientation="vertical">

    <TextView
        android:id="@+id/item_longclicked_viewImage"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:gravity="center"
        android:text="查看图片"
        android:textColor="@android:color/white"
        android:textSize="16sp" />

    <View
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="@color/gray_9F" />

    <TextView
        android:id="@+id/item_longclicked_saveImage"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:gravity="center"
        android:text="保存图片"
        android:textColor="@android:color/white"
        android:textSize="16sp" />

</LinearLayout>

通过GestureDetector获取按下的位置,来定位PopWindow显示的位置

private GestureDetector gestureDetector;
private int downX, downY;


    gestureDetector = new GestureDetector(this, new GestureDetector.SimpleOnGestureListener() {
            @Override
            public void onLongPress(MotionEvent e) {
                downX = (int) e.getX();
                downY = (int) e.getY();
            }
        });

在Activity中对webview的监听

_mWebview.setOnLongClickListener(new View.OnLongClickListener() {
     @Override
     public boolean onLongClick(View v) {
        WebView.HitTestResult result = ((WebView)v).getHitTestResult();
        if (null == result) 
            return false;
        int type = result.getType();
        if (type == WebView.HitTestResult.UNKNOWN_TYPE) 
            return false;
        if (type == WebView.HitTestResult.EDIT_TEXT_TYPE) {
          //let TextViewhandles context menu return true;
         }
final ItemLongClickedPopWindow itemLongClickedPopWindow = new ItemLongClickedPopWindow(HtmlActivity.this,ItemLongClickedPopWindow.IMAGE_VIEW_POPUPWINDOW, UIUtils.dip2px(120), UIUtils.dip2px(90));
    // Setup custom handlingdepending on the type
   switch (type) {
       case WebView.HitTestResult.PHONE_TYPE: // 处理拨号
           break;
       case WebView.HitTestResult.EMAIL_TYPE: // 处理Email
           break;
       case WebView.HitTestResult.GEO_TYPE: // TODO
           break;
       case WebView.HitTestResult.SRC_ANCHOR_TYPE: // 超链接
           // Log.d(DEG_TAG, "超链接");
           break;
       case WebView.HitTestResult.SRC_IMAGE_ANCHOR_TYPE:
           break;
       case WebView.HitTestResult.IMAGE_TYPE: // 处理长按图片的菜单项
           imgurl = result.getExtra();
           //通过GestureDetector获取按下的位置,来定位PopWindow显示的位置
           itemLongClickedPopWindow.showAtLocation(v,        Gravity.TOP|Gravity.LEFT, downX, downY + 10);
           break;
       default:
           break;
    }

itemLongClickedPopWindow.getView(R.id.item_longclicked_viewImage)
    .setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View v) {
               itemLongClickedPopWindow.dismiss();
           }
     });
                                                                          itemLongClickedPopWindow.getView(R.id.item_longclicked_saveImage)
    .setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View v) {
               itemLongClickedPopWindow.dismiss();
               new SaveImage().execute(); // Android 4.0以后要使用线程来访问网络
           }
    });
    return true;
  }
});

最后下载图片

private String imgurl = "";

    /***
     * 功能:用线程保存图片
     *
     * @author wangyp
     */
    private class SaveImage extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... params) {
            String result = "";
            try {
                String sdcard = Environment.getExternalStorageDirectory().toString();
                File file = new File(sdcard + "/Download");
                if (!file.exists()) {
                    file.mkdirs();
                }
                int idx = imgurl.lastIndexOf(".");
                String ext = imgurl.substring(idx);
                file = new File(sdcard + "/Download/" + new Date().getTime() + ext);
                InputStream inputStream = null;
                URL url = new URL(imgurl);
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setRequestMethod("GET");
                conn.setConnectTimeout(20000);
                if (conn.getResponseCode() == 200) {
                    inputStream = conn.getInputStream();
                }
                byte[] buffer = new byte[4096];
                int len = 0;
                FileOutputStream outStream = new FileOutputStream(file);
                while ((len = inputStream.read(buffer)) != -1) {
                    outStream.write(buffer, 0, len);
                }
                outStream.close();
                result = "图片已保存至:" + file.getAbsolutePath();
            } catch (Exception e) {
                result = "保存失败!" + e.getLocalizedMessage();
            }
            return result;
        }

        @Override
        protected void onPostExecute(String result) {
            showToast(result);
        }
    }

原文:http://www.educity.cn/wenda/179077.html

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Android WebView Long Press长按保存图片到手机

private String imgurl = "";     /***      * 功能:长按图片保存到手机      */     @Override     public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {         super.onCreateContextMenu(menu, v, menuInfo);         MenuItem.OnMenuItemClickListener handler = new MenuItem.OnMenuItemClickListener() {             public boolean onMenuItemClick(MenuItem item) {                 if (item.getTitle() == "保存到手机") {                     new SaveImage().execute(); // Android 4.0以后要使用线程来访问网络                 } else {                     return false;                 }                 return true;             }         };         if (v instanceof WebView) {             WebView.HitTestResult result = ((WebView) v).getHitTestResult();             if (result != null) {                 int type = result.getType();                 if (type == WebView.HitTestResult.IMAGE_TYPE || type == WebView.HitTestResult.SRC_IMAGE_ANCHOR_TYPE) {                     imgurl = result.getExtra();                     menu.setHeaderTitle("提示");                     menu.add(0, v.getId(), 0, "保存到手机").setOnMenuItemClickListener(handler);                 }             }         }     }     /***      * 功能:用线程保存图片      *       * @author wangyp      *       */     private class SaveImage extends AsyncTask<String, Void, String> {         @Override         protected String doInBackground(String... params) {             String result = "";             try {                 String sdcard = Environment.getExternalStorageDirectory().toString();                 File file = new File(sdcard + "/Download");                 if (!file.exists()) {                     file.mkdirs();                 }                 int idx = imgurl.lastIndexOf(".");                 String ext = imgurl.substring(idx);                 file = new File(sdcard + "/Download/" + new Date().getTime() + ext);                 InputStream inputStream = null;                 URL url = new URL(imgurl);                 HttpURLConnection conn = (HttpURLConnection) url.openConnection();                 conn.setRequestMethod("GET");                 conn.setConnectTimeout(20000);                 if (conn.getResponseCode() == 200) {                     inputStream = conn.getInputStream();                 }                 byte[] buffer = new byte[4096];                 int len = 0;                 FileOutputStream outStream = new FileOutputStream(file);                 while ((len = inputStream.read(buffer)) != -1) {                     outStream.write(buffer, 0, len);                 }                 outStream.close();                 result = "图片已保存至:" + file.getAbsolutePath();             } catch (Exception e) {                 result = "保存失败!" + e.getLocalizedMessage();             }             return result;         }         @Override         protected void onPostExecute(String result) {             MsgBox("提示", result);         }     }

Android WebView截取所有内容生成长图在5.0以上系统异常问题

最近在做webview截取所有内容生成长图时出现一些问题,在Android5.0以下系统能正常生成长图,但是在5.0以上会出现只能截取第一屏的内容,剩下的全部为空白,查看资料发现原来是系统在5.0+版本上,Android对webview做了优化,为了减少内存占用以提高性能,因此在默认情况下会智能的绘制html中需要绘制的部分,其实就是当前屏幕展示的html内容,因此会出现未显示的图像是空白的。解决方法如下:


如上图:在activity的onCreate方法中的setContentView前加上一句enableSlowWholeDocumentDraw();意思为取消系统的智能绘制,当然这样之后性能会有所下降,但为了实现功能,也只能如此。
加上之后在Android5.0以下系统会崩溃,那是因为在5.0以下没有enableSlowWholeDocumentDraw()这个方法,因此需要做个判断,获取本机系统版本号,当版本号大于5.0则调用enableSlowWholeDocumentDraw()方法,否则不调用。
代码为:API=21即为Android5.0系统

if (android.os.Build.VERSION.SDK_INT >= 21) {
    enableSlowWholeDocumentDraw();
}
下面为生成长图代码:

public Bitmap viewShot(final View view) {
    if (view == null)
        return null;
    view.setDrawingCacheEnabled(true);
    view.buildDrawingCache();
    int measureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
    view.measure(measureSpec, measureSpec);
    if (view.getMeasuredWidth() <= 0 || view.getMeasuredHeight() <= 0) {
        return null;
    }
    Bitmap bm;
    try {
        bm = Bitmap.createBitmap(view.getMeasuredWidth(), view.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
    } catch (OutOfMemoryError e) {
        System.gc();
        try {
            bm = Bitmap.createBitmap(view.getMeasuredWidth(), view.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
        } catch (OutOfMemoryError ee) {
            return null;
        }
    }
    Canvas bigCanvas = new Canvas(bm);
    Paint paint = new Paint();
    int iHeight = bm.getHeight();
    bigCanvas.drawBitmap(bm, 0, iHeight, paint);
    view.draw(bigCanvas);
    showToast(getString(R.string.already_share_save_img));
    return bm;
}
————————————————
版权声明:本文为CSDN博主「A_mnesia」的原创文章,遵循 CC 4.0 BY-SA 版权协议,转载请附上原文出处链接及本声明。
原文链接:https://blog.csdn.net/m13984458297/article/details/78687015

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