我有一个问题，我在WebView中加载了一个页面 - 我不打算为整个应用程序发布代码，因为我的问题非常具体：我的HTML页面中的“选择文件”按钮适用于Android Studio创建了模拟器，但没有其他地方。
该按钮运行此代码：
<input type='file' id='fileInput' accept='text/plain' onchange='openFile(event);'>
var openFile = function(event) {
var input = event.target;
var reader = new FileReader();
reader.onload = function(e){
/* various string parsing */
};
reader.readAsText(input.files[0]);
};
这在我的模拟器上工作得很好，这是API 23：点击按钮打开设备的默认文件选择器来选择文件。但是，在我的实际手机上，即API 16，单击此按钮不会执行任何操作。此外，在Genymotion模拟器（API 18）上，单击按钮不会执行任何操作。有什么我可以做的来解决这个问题吗？该按钮在我的手机和Genymotion模拟器上都没有产生任何错误消息，它只是坐在那里没有任何反应。
我需要应用程序在允许语音到文本的设备上工作，所以我不仅可以使用模拟器，而且我可以使用。
为选择文件设置WebChromeClient
码
import android.app.AlertDialog;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.webkit.JavascriptInterface;
import android.webkit.ValueCallback;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;
import android.widget.Toast;
import org.apache.http.util.EncodingUtils;
public class BrowserScreen extends Activity {
private WebView webView;
private String url = "url";
private ValueCallback<Uri> mUploadMessage;
private final static int FILECHOOSER_RESULTCODE = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.browser_activity);
initFields();
setListeners();
}
public void initFields() {
// TODO Auto-generated method stub
webView = (WebView) findViewById(R.id.webView1);
webView.getSettings().setJavaScriptEnabled(true);
webView.getSettings().setBuiltInZoomControls(true);
webView.getSettings().setAllowFileAccess(true);
}
public void setListeners() {
// TODO Auto-generated method stub
webView.setWebViewClient(new WebViewClient() {
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
webView.loadUrl("about:blank");
view.clearHistory();
}
});
webView.setWebChromeClient(new WebChromeClient() {
public void onProgressChanged(WebView view, int progress) {
}
//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/*");
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("*/*");
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/*");
startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
}
});
webView.loadUrl(url);
final MyJavaScriptInterface myJavaScriptInterface
= new MyJavaScriptInterface(this);
webView.addJavascriptInterface(myJavaScriptInterface, "AndroidFunction");
}
@Override
public void onBackPressed() {
// TODO Auto-generated method stub
if (webView.canGoBack() == true) {
webView.goBack();
} else {
super.onBackPressed();
}
}
public class MyJavaScriptInterface {
Context mContext;
MyJavaScriptInterface(Context c) {
mContext = c;
}
@JavascriptInterface
public void showToast(String toast) {
Toast.makeText(mContext, toast, Toast.LENGTH_SHORT).show();
// webView.loadUrl("javascript:document.getElementById(\"Button3\").innerHTML = \"bye\";");
}
@JavascriptInterface
public void openAndroidDialog() {
AlertDialog.Builder myDialog
= new AlertDialog.Builder(BrowserScreen.this);
myDialog.setTitle("DANGER!");
myDialog.setMessage("You can do what you want!");
myDialog.setPositiveButton("ON", null);
myDialog.show();
}
}
@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;
}
}
}
的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(YOUR_WEBVIEW_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();
}
}
}
}