我一直在努力从WebView上传文件。我在谷歌上搜索并实施了所有建议的解决方案(例如这篇SO帖子),但没有一个可行。

我有一个HTML页面与以下代码上传文件。

<form method="POST" enctype="multipart/form-data">
  File to upload: <input type="file" name="uploadfile">&nbsp;&nbsp;
  <input type="submit" value="Press to Upload..."> to upload the file!
</form>

它在桌面浏览器如Firefox和内置浏览器中运行良好 的模拟器/ AVD,即,当我点击“浏览…”按钮渲染 元素,浏览器打开一个对话框 框,在那里我可以选择一个文件上传。

然而,在android 3.0模拟器/ AVD中,当我点击“选择” 文件”,什么都没有发生,没有文件对话框被打开!


当前回答

我发现我需要3个接口定义,以处理不同版本的android。

public void openFileChooser(ValueCallback < Uri > uploadMsg) {
  mUploadMessage = uploadMsg;
  Intent i = new Intent(Intent.ACTION_GET_CONTENT);
  i.addCategory(Intent.CATEGORY_OPENABLE);
  i.setType("image/*");
  FreeHealthTrack.this.startActivityForResult(Intent.createChooser(i, "Image Chooser"), FILECHOOSER_RESULTCODE);
}

public void openFileChooser(ValueCallback < Uri > uploadMsg, String acceptType) {
  openFileChooser(uploadMsg);
}

public void openFileChooser(ValueCallback < Uri > uploadMsg, String acceptType, String capture) {
  openFileChooser(uploadMsg);
}

其他回答

我发现我需要3个接口定义,以处理不同版本的android。

public void openFileChooser(ValueCallback < Uri > uploadMsg) {
  mUploadMessage = uploadMsg;
  Intent i = new Intent(Intent.ACTION_GET_CONTENT);
  i.addCategory(Intent.CATEGORY_OPENABLE);
  i.setType("image/*");
  FreeHealthTrack.this.startActivityForResult(Intent.createChooser(i, "Image Chooser"), FILECHOOSER_RESULTCODE);
}

public void openFileChooser(ValueCallback < Uri > uploadMsg, String acceptType) {
  openFileChooser(uploadMsg);
}

public void openFileChooser(ValueCallback < Uri > uploadMsg, String acceptType, String capture) {
  openFileChooser(uploadMsg);
}

我找到了一个适合我的解决方案!在proguard-android.txt文件中增加一条规则:

-keepclassmembers class * extends android.webkit.WebChromeClient {
     public void openFileChooser(...);
}

自定义WebChromeClient:

class AppChromeClient(private val fragmentWeakReference: WeakReference<WebViewFragment>) :
WebChromeClient() {
private var openFileCallback: ValueCallback<Array<Uri>>? = null

override fun onShowFileChooser(
    webView: WebView?,
    filePathCallback: ValueCallback<Array<Uri>>?,
    fileChooserParams: FileChooserParams?
): Boolean {
    if (filePathCallback == null) {
        return (super.onShowFileChooser(webView, filePathCallback, fileChooserParams))
    }
    openFileCallback = filePathCallback
    val webViewFragment = fragmentWeakReference.get() ?: return false
    webViewFragment.launchGetMultipleContents("*/*")

    return true
}

fun receiveFileCallback(result: Array<Uri>) {
    openFileCallback?.onReceiveValue(result)
    openFileCallback = null
}
}

WebViewFragment:

class WebViewFragment : Fragment() {
    private var _binding: FragmentWebviewBinding? = null
    private val binding get() = _binding!!
    private lateinit var webView: WebView
    private val chromeClient = AppChromeClient(WeakReference(this))
    private var contentLauncher: ActivityResultLauncher<String> = getMultipleContentLauncher()

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        _binding = FragmentWebviewBinding.inflate(inflater, container, false)

        webView.webChromeClient = chromeClient
        val url = requireContext().getString(R.string.app_domain)
        webView.setting.javaScriptEnabled = true
        webView.loadUrl(url)
        return binding.root
    }


    private fun getMultipleContentLauncher(): ActivityResultLauncher<String> {
        return this.registerForActivityResult(ActivityResultContracts.GetMultipleContents()) { list ->
            if (list.isEmpty()) {
                showToast("No files selected")
            }
            chromeClient.receiveFileCallback(list.toTypedArray())
        }
    }


    fun launchGetMultipleContents(type: String) {
        contentLauncher.launch(type)
    }
}

我发现有必要在Android 4.1中定义公共void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture)。然后我采用了米歇尔·奥利弗的解决方案。

这是一个完整的解决方案,所有的android版本,我有一个艰难的时间与此。

public class MyWb extends Activity {
/** Called when the activity is first created. */

WebView web;
ProgressBar progressBar;

private ValueCallback<Uri> mUploadMessage;  
 private final static int FILECHOOSER_RESULTCODE=1;  

 @Override  
 protected void onActivityResult(int requestCode, int resultCode,  
                                    Intent intent) {  
  if(requestCode==FILECHOOSER_RESULTCODE)  
  {  
   if (null == mUploadMessage) return;  
            Uri result = intent == null || resultCode != RESULT_OK ? null  
                    : intent.getData();  
            mUploadMessage.onReceiveValue(result);  
            mUploadMessage = null;  
  }
  }  

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    web = (WebView) findViewById(R.id.webview01);
    progressBar = (ProgressBar) findViewById(R.id.progressBar1);

    web = new WebView(this);  
    web.getSettings().setJavaScriptEnabled(true);
    web.loadUrl("http://www.script-tutorials.com/demos/199/index.html");
    web.setWebViewClient(new myWebClient());
    web.setWebChromeClient(new WebChromeClient()  
    {  
           //The undocumented magic method override  
           //Eclipse will swear at you if you try to put @Override here  
        // For Android 3.0+
        public void openFileChooser(ValueCallback<Uri> uploadMsg) {  

            mUploadMessage = uploadMsg;  
            Intent i = new Intent(Intent.ACTION_GET_CONTENT);  
            i.addCategory(Intent.CATEGORY_OPENABLE);  
            i.setType("image/*");  
            MyWb.this.startActivityForResult(Intent.createChooser(i,"File Chooser"), FILECHOOSER_RESULTCODE);  

           }

        // For Android 3.0+
           public void openFileChooser( ValueCallback uploadMsg, String acceptType ) {
           mUploadMessage = uploadMsg;
           Intent i = new Intent(Intent.ACTION_GET_CONTENT);
           i.addCategory(Intent.CATEGORY_OPENABLE);
           i.setType("*/*");
           MyWb.this.startActivityForResult(
           Intent.createChooser(i, "File Browser"),
           FILECHOOSER_RESULTCODE);
           }

        //For Android 4.1
           public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture){
               mUploadMessage = uploadMsg;  
               Intent i = new Intent(Intent.ACTION_GET_CONTENT);  
               i.addCategory(Intent.CATEGORY_OPENABLE);  
               i.setType("image/*");  
               MyWb.this.startActivityForResult( Intent.createChooser( i, "File Chooser" ), MyWb.FILECHOOSER_RESULTCODE );

           }

    });  


    setContentView(web);  


}

public class myWebClient extends WebViewClient
{
    @Override
    public void onPageStarted(WebView view, String url, Bitmap favicon) {
        // TODO Auto-generated method stub
        super.onPageStarted(view, url, favicon);
    }

    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        // TODO Auto-generated method stub

        view.loadUrl(url);
        return true;

    }

    @Override
    public void onPageFinished(WebView view, String url) {
        // TODO Auto-generated method stub
        super.onPageFinished(view, url);

        progressBar.setVisibility(View.GONE);
    }
}

//flipscreen not loading again
@Override
public void onConfigurationChanged(Configuration newConfig){        
    super.onConfigurationChanged(newConfig);
}

// To handle "Back" key press event for WebView to go back to previous screen.
/*@Override
public boolean onKeyDown(int keyCode, KeyEvent event) 
{
    if ((keyCode == KeyEvent.KEYCODE_BACK) && web.canGoBack()) {
        web.goBack();
        return true;
    }
    return super.onKeyDown(keyCode, event);
}*/
}

我还想补充一点,像这个例子中的“上传页面”,不会在< 4个版本上工作,因为它有一个图像预览功能,如果你想让它工作,使用一个简单的php上传没有预览。

更新:

请在这里找到棒棒糖装置的解决方案,感谢gauntface

更新2:

完整的解决方案,所有android设备,直到奥利奥这里,这是更高级的版本,你应该看看,也许它可以帮助。