Android 嵌套H5 网页，图片上传无法调用手机图片以及嵌套网页中无法调用另一款APP问题记录

最近项目中用到安卓原生APP 嵌套H5网页，使用安卓原生WebView实现，主要遇到以下两种问题，特此记录：

1. 在H5页面，返回直接回到APP中
   1. 监听安卓的返回事件就行了 

      1. @Override
         public boolean onKeyDown(int keyCode, KeyEvent event) {
             if(keyCode==KeyEvent.KEYCODE_BACK&&shejian.canGoBack()){
                 shejian.goBack();
                 return true;
             }else{
                 onBackPressed();
             }
             return super.onKeyDown(keyCode, event);
         }

2. 在嵌套的网页中，点击链接跳转至另一款APP中报错
   1. 好像是因为WebView 只会以Http、Https的形式加载链接，导致 liktin://类链接无法加载
   2. 处理方法：重写webView的 WebViewClient 方法，判断url是否是此类链接，具体代码如下：

      WebViewClient webViewClient = new WebViewClient() {
          public boolean shouldOverrideUrlLoading(WebView wv, String url) {
              if (url == null) return false;
              try {
                  //判断是不是打开APP的链接
                  if (url.startsWith("liktin://")) {
                      Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
                      startActivity(intent);
                      return true;
                  }
              } catch (Exception e) { //防止crash (如果手机上没有安装处理某个scheme开头的url的APP, 会导致crash)
                  Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.shejian360.com/download/zxks/androidDownload.html"));
                  startActivity(intent);
                  return true;//没有安装该app时，返回true，表示拦截自定义链接，跳转到下载页面
              }
              //处理http和https开头的url
              wv.loadUrl(url);
              return true;
          }
      };       
      //设置WebView 的WebViewClient 
      shejian.setWebViewClient(webViewClient);

3. 嵌套的网页中，无法调起图片上传
   1. 试了网上说的几种方法，最后用此方法解决问题

      1. private ValueCallback mUploadMessage;
         public ValueCallback uploadMessage;
         public static final int REQUEST_SELECT_FILE = 100;
         private final static int FILECHOOSER_RESULTCODE = 2;

         shejian.setWebChromeClient(new WebChromeClient() {
             // For Android 3.0+
             public void openFileChooser(ValueCallback uploadMsg) {
                 mUploadMessage = uploadMsg;
                 Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                 i.addCategory(Intent.CATEGORY_OPENABLE);
                 i.setType("image/*");
                 shejian.this.startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
             }
         
             public void openFileChooser(ValueCallback uploadMsg, String acceptType) {
                 openFileChooser(uploadMsg);
             }
         
             public void openFileChooser(ValueCallback uploadMsg, String acceptType, String capture) {
                 openFileChooser(uploadMsg);
             }
         
             // For Lollipop 5.0+ Devices
             @TargetApi(Build.VERSION_CODES.LOLLIPOP)
             public boolean onShowFileChooser(WebView mWebView, ValueCallback filePathCallback, WebChromeClient.FileChooserParams fileChooserParams) {
                 if (uploadMessage != null) {
                     uploadMessage.onReceiveValue(null);
                     uploadMessage = null;
                 }
                 uploadMessage = filePathCallback;
                 Intent intent = fileChooserParams.createIntent();
                 try {
                     startActivityForResult(intent, REQUEST_SELECT_FILE);
                 } catch (ActivityNotFoundException e) {
                     uploadMessage = null;
                     return false;
                 }
                 return true;
             }
         });

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        if (requestCode == REQUEST_SELECT_FILE) {
            if (uploadMessage == null)
                return;
            uploadMessage.onReceiveValue(WebChromeClient.FileChooserParams.parseResult(resultCode, intent));
            uploadMessage = null;
        }
    } else if (requestCode == FILECHOOSER_RESULTCODE) {
        if (null == mUploadMessage)
            return;
        Uri result = intent == null || resultCode != MainActivity.RESULT_OK ? null : intent.getData();
        mUploadMessage.onReceiveValue(result);
        mUploadMessage = null;
    }
}