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：
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();

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