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

Webview -单个和多个文件选择

你需要两分钟来实现这段代码:

build.gradle

implementation 'com.github.angads25:filepicker:1.1.1'

java代码:

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.ValueCallback;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.bivoiclient.utils.Constants;
import com.github.angads25.filepicker.controller.DialogSelectionListener;
import com.github.angads25.filepicker.model.DialogConfigs;
import com.github.angads25.filepicker.model.DialogProperties;
import com.github.angads25.filepicker.view.FilePickerDialog;

import java.io.File;

public class WebBrowserScreen extends Activity {

    private WebView webView;
    private ValueCallback<Uri[]> mUploadMessage;
    private FilePickerDialog dialog;
    private String LOG_TAG = "DREG";
    private Uri[] results;

    @SuppressLint("SetJavaScriptEnabled")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_complain);

        webView = findViewById(R.id.webview);
        WebSettings webSettings = webView.getSettings();
        webSettings.setAppCacheEnabled(true);
        webSettings.setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);
        webSettings.setJavaScriptEnabled(true);
        webSettings.setLoadWithOverviewMode(true);
        webSettings.setAllowFileAccess(true);
        webView.setWebViewClient(new PQClient());
        webView.setWebChromeClient(new PQChromeClient());
        if (Build.VERSION.SDK_INT >= 19) {
            webView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
        } else {
            webView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
        }

        webView.loadUrl(Constants.COMPLAIN_URL);

    }

    private void openFileSelectionDialog() {

        if (null != dialog && dialog.isShowing()) {
            dialog.dismiss();
        }

        //Create a DialogProperties object.
        final DialogProperties properties = new DialogProperties();

        //Instantiate FilePickerDialog with Context and DialogProperties.
        dialog = new FilePickerDialog(WebBrowserScreen.this, properties);
        dialog.setTitle("Select a File");
        dialog.setPositiveBtnName("Select");
        dialog.setNegativeBtnName("Cancel");
        properties.selection_mode = DialogConfigs.MULTI_MODE; // for multiple files
//        properties.selection_mode = DialogConfigs.SINGLE_MODE; // for single file
        properties.selection_type = DialogConfigs.FILE_SELECT;

        //Method handle selected files.
        dialog.setDialogSelectionListener(new DialogSelectionListener() {
            @Override
            public void onSelectedFilePaths(String[] files) {
                results = new Uri[files.length];
                for (int i = 0; i < files.length; i++) {
                    String filePath = new File(files[i]).getAbsolutePath();
                    if (!filePath.startsWith("file://")) {
                        filePath = "file://" + filePath;
                    }
                    results[i] = Uri.parse(filePath);
                    Log.d(LOG_TAG, "file path: " + filePath);
                    Log.d(LOG_TAG, "file uri: " + String.valueOf(results[i]));
                }
                mUploadMessage.onReceiveValue(results);
                mUploadMessage = null;
            }
        });
        dialog.setOnCancelListener(new DialogInterface.OnCancelListener() {
            @Override
            public void onCancel(DialogInterface dialogInterface) {
                if (null != mUploadMessage) {
                    if (null != results && results.length >= 1) {
                        mUploadMessage.onReceiveValue(results);
                    } else {
                        mUploadMessage.onReceiveValue(null);
                    }
                }
                mUploadMessage = null;
            }
        });
        dialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
            @Override
            public void onDismiss(DialogInterface dialogInterface) {
                if (null != mUploadMessage) {
                    if (null != results && results.length >= 1) {
                        mUploadMessage.onReceiveValue(results);
                    } else {
                        mUploadMessage.onReceiveValue(null);
                    }
                }
                mUploadMessage = null;
            }
        });

        dialog.show();

    }

    public class PQChromeClient extends WebChromeClient {

        @Override
        public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {
            // Double check that we don't have any existing callbacks
            if (mUploadMessage != null) {
                mUploadMessage.onReceiveValue(null);
            }
            mUploadMessage = filePathCallback;

            openFileSelectionDialog();

            return true;
        }

    }

    //Add this method to show Dialog when the required permission has been granted to the app.
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
        switch (requestCode) {
            case FilePickerDialog.EXTERNAL_READ_PERMISSION_GRANT: {
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    if (dialog != null) {
                        openFileSelectionDialog();
                    }
                } else {
                    //Permission has not been granted. Notify the user.
                    Toast.makeText(WebBrowserScreen.this, "Permission is Required for getting list of files", Toast.LENGTH_SHORT).show();
                }
            }
        }
    }

    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // Check if the key event was the Back button and if there's history
        if ((keyCode == KeyEvent.KEYCODE_BACK) && webView.canGoBack()) {
            webView.goBack();
            return true;
        }
        // If it wasn't the Back key or there's no web page history, bubble up to the default
        // system behavior (probably exit the activity)

        return super.onKeyDown(keyCode, event);
    }


    public class PQClient extends WebViewClient {
        ProgressBar progressDialog;

        public boolean shouldOverrideUrlLoading(WebView view, String url) {

            // If url contains mailto link then open Mail Intent
            if (url.contains("mailto:")) {

                // Could be cleverer and use a regex
                //Open links in new browser
                view.getContext().startActivity(
                        new Intent(Intent.ACTION_VIEW, Uri.parse(url)));

                // Here we can open new activity

                return true;

            } else {
                // Stay within this webview and load url
                view.loadUrl(url);
                return true;
            }
        }

        // Show loader on url load
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            // Then show progress  Dialog
            // in standard case YourActivity.this
            if (progressDialog == null) {
                progressDialog = findViewById(R.id.progressBar);
                progressDialog.setVisibility(View.VISIBLE);
            }
        }

        // Called when all page resources loaded
        public void onPageFinished(WebView view, String url) {
            webView.loadUrl("javascript:(function(){ " +
                    "document.getElementById('android-app').style.display='none';})()");

            try {
                // Close progressDialog
                progressDialog.setVisibility(View.GONE);
            } catch (Exception exception) {
                exception.printStackTrace();
            }
        }
    }

}

其他回答

你访问过这个链接吗? http://groups.google.com/group/android-developers/browse_thread/thread/dcaf8b2fdd8a90c4/62d5e2ffef31ebdb

http://moazzam-khan.com/blog/?tag=android-upload-file

http://evgenyg.wordpress.com/2010/05/01/uploading-files-multipart-post-apache/

通过javalib Apache Commons上传文件的简明示例

我想你会从中得到帮助的

这是我发现的唯一有效的解决方案!

WebView webview;

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;

    }
}

// Next part 

class MyWebChromeClient extends WebChromeClient {
    // The undocumented magic method override
    // Eclipse will swear at you if you try to put @Override here
    public void openFileChooser(ValueCallback<Uri> uploadMsg) {

        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        Cv5appActivity.this.startActivityForResult(
                Intent.createChooser(i, "Image Browser"),
                FILECHOOSER_RESULTCODE);
    }
}

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)
    }
}

我花了将近一个月的时间研究这个问题。一切都失败了。在多个网站中看到的所有代码都不工作。但这里存在最好的解决方案

https://github.com/chiclaim/android-webview-upload-file

步骤

1)点击克隆或下载

2)在本地目录中获取zip fle

3)解压压缩文件

4)开放Android工作室

5)转到文件---->打开>导航到你解压内容的目录。

6)在webView中更改所需的web url。loadUrl(“您的url hre”);在MainActivity.java

7)适用于Android studio 3.4.2版本