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">
<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
Android 8的Kotlin解决方案:
private var mUploadMessage: ValueCallback<Uri>? = null
private var uploadMessage: ValueCallback<Array<Uri>>? = null
常量:
const val FILECHOOSER_RESULTCODE = 1
const val REQUEST_SELECT_FILE = 100
WebView设置:
webView.webChromeClient = object : WebChromeClient() {
override fun onPermissionRequest(request: PermissionRequest?) {
Log.d("MainActivity", "onPermissionRequest")
requestPermission(request)
}
// For Android 3.0+
fun openFileChooser(uploadMsg: ValueCallback<*>, acceptType: String) {
mUploadMessage = uploadMsg as ValueCallback<Uri>
val i = Intent(Intent.ACTION_GET_CONTENT)
i.addCategory(Intent.CATEGORY_OPENABLE)
i.type = "*/*"
this@MainActivity.startActivityForResult(
Intent.createChooser(i, "File Browser"),
FILECHOOSER_RESULTCODE)
}
//For Android 4.1
fun openFileChooser(uploadMsg: ValueCallback<Uri>, acceptType: String, capture: String) {
mUploadMessage = uploadMsg
val i = Intent(Intent.ACTION_GET_CONTENT)
i.addCategory(Intent.CATEGORY_OPENABLE)
i.type = "image/*"
this@MainActivity.startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE)
}
protected fun openFileChooser(uploadMsg: ValueCallback<Uri>) {
mUploadMessage = uploadMsg
val intent = Intent(Intent.ACTION_GET_CONTENT)
intent.addCategory(Intent.CATEGORY_OPENABLE)
intent.type = "*/*"
startActivityForResult(Intent.createChooser(intent, "File Chooser"), FILECHOOSER_RESULTCODE)
}
override fun onShowFileChooser(webView: WebView?, filePathCallback: ValueCallback<Array<Uri>>?, fileChooserParams: FileChooserParams?): Boolean {
uploadMessage?.onReceiveValue(null)
uploadMessage = null
uploadMessage = filePathCallback
val intent = fileChooserParams!!.createIntent()
try {
startActivityForResult(intent, REQUEST_SELECT_FILE)
} catch (e: ActivityNotFoundException) {
uploadMessage = null
Toast.makeText(applicationContext, "Cannot Open File Chooser", Toast.LENGTH_LONG).show()
return false
}
return true
}
}
onactivityresult部分:
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
if (requestCode === REQUEST_SELECT_FILE) {
if (uploadMessage == null)
return
print("result code = " + resultCode)
var results: Array<Uri>? = WebChromeClient.FileChooserParams.parseResult(resultCode, data)
uploadMessage?.onReceiveValue(results)
uploadMessage = null
}
} else if (requestCode === FILECHOOSER_RESULTCODE) {
if (null == mUploadMessage)
return
// Use MainActivity.RESULT_OK if you're implementing WebView inside Fragment
// Use RESULT_OK only if you're implementing WebView inside an Activity
val result = if (intent == null || resultCode !== RESULT_OK) null else intent.data
mUploadMessage?.onReceiveValue(result)
mUploadMessage = null
} else
Toast.makeText(applicationContext, "Failed to Upload Image", Toast.LENGTH_LONG).show()
}
请注意，我们的意图变量称为“数据”。
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
谷歌自己的浏览器为这个问题提供了一个全面的解决方案，它保证了自己的类:
openFileChooser在Android 4.0.4中的实现
android4.0.4中的UploadHandler类
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)
}
}
我是android的新手，在这方面也很吃力。根据谷歌参考指南WebView。
默认情况下，WebView不提供类似浏览器的小部件 启用JavaScript和网页错误被忽略。如果你的目标是 只是显示一些HTML作为你的UI的一部分，这可能是好的; 除了阅读，用户不需要与网页进行交互， 网页也不需要与用户交互。如果你真的 想要一个成熟的web浏览器，那么您可能需要调用 浏览器应用程序的URL意图，而不是显示它与 WebView。
我在mainactivity .java中执行的示例代码。
Uri uri = Uri.parse("https://www.example.com");
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
Excuted
package example.com.myapp;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.content.Intent;
import android.net.Uri;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Uri uri = Uri.parse("http://www.example.com/");
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
getSupportActionBar().hide();
}}
