晚上好，我请求帮助，谁可以遇到类似问题并找到解决方案。有一个典型的Android应用程序用于在WebView中打开页面，并且能够在此页面上下载文件。问题是应用程序在4.1,4.2,4.3 orroids上工作得很好，它适用于5,6,7甚至8个android，但是在android 6的控制下的一个特定设备上，它不想处理文件上传...具体来说，有问题的设备无法选择文件 - 小米Redmi Note3 Build / MMB29M Android 6.0.1如果你看一下这台机器上的代码，我们看到消息“mFilePathCallback == null”，具体推断，了解什么是故障 - 为什么这款手机我无法从活动中得到结果我无法理解，我需要帮助......什么？小米设备中的这样一个功能可以具有不同的功能吗？代码是典型的，无论我在哪里测试，除了这个设备......
可能是什么问题？
MainActivity
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.content.ClipData;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.os.Parcelable;
import android.provider.MediaStore;
import android.support.annotation.NonNull;
import android.util.Log;
import android.view.KeyEvent;
import android.webkit.ValueCallback;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class MainActivity extends Activity {
WebView mWebView;
private static final int INPUT_FILE_REQUEST_CODE = 1;
private static final int FILECHOOSER_RESULTCODE = 1;
private static final String TAG = MainActivity.class.getSimpleName();
private ValueCallback<Uri> mUploadMessage;
private Uri mCapturedImageURI = null;
private ValueCallback<Uri[]> mFilePathCallback;
private String mCameraPhotoPath;
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
if (requestCode != INPUT_FILE_REQUEST_CODE || mFilePathCallback == null) {
super.onActivityResult(requestCode, resultCode, data);
Toast.makeText(getApplicationContext(), "mFilePathCallback == null", Toast.LENGTH_LONG).show();
return;
}
Uri[] results = null;
// Check that the response is a good one
if (resultCode == Activity.RESULT_OK) {
if (data == null) {
// If there is not data, then we may have taken a photo
if (mCameraPhotoPath != null) {
results = new Uri[]{Uri.parse(mCameraPhotoPath)};
}
} else {
String dataString = data.getDataString();
ClipData clipData = data.getClipData();
if (clipData != null) {
results = new Uri[clipData.getItemCount()];
for (int i = 0; i < clipData.getItemCount(); i++) {
ClipData.Item item = clipData.getItemAt(i);
results[i] = item.getUri();
}
Toast.makeText(getApplicationContext(), "data CL: " + results[0], Toast.LENGTH_LONG).show();
}else{
Toast.makeText(getApplicationContext(), "no data CL ", Toast.LENGTH_LONG).show();
}
if (dataString != null) {
results = new Uri[]{Uri.parse(dataString)};
Toast.makeText(getApplicationContext(), "data STR: " + results[0], Toast.LENGTH_LONG).show();
}else{
Toast.makeText(getApplicationContext(), "no data STR ", Toast.LENGTH_LONG).show();
}
}
}else{
Toast.makeText(getApplicationContext(), "no result from activity", Toast.LENGTH_LONG).show();
}
mFilePathCallback.onReceiveValue(results);
mFilePathCallback = null;
} else if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.KITKAT) {
if (requestCode != FILECHOOSER_RESULTCODE || mUploadMessage == null) {
super.onActivityResult(requestCode, resultCode, data);
return;
}
if (requestCode == FILECHOOSER_RESULTCODE) {
if (null == this.mUploadMessage) {
return;
}
Uri result = null;
try {
if (resultCode != RESULT_OK) {
result = null;
} else {
// retrieve from the private variable if the intent is null
result = data == null ? mCapturedImageURI : data.getData();
}
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "activity :" + e, Toast.LENGTH_LONG).show();
}
mUploadMessage.onReceiveValue(result);
mUploadMessage = null;
}
}
return;
}
private File createImageFile() throws IOException {
// Create an image file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_" + timeStamp + "_";
File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
File imageFile = File.createTempFile(imageFileName, /* prefix */
".jpg", /* suffix */
storageDir /* directory */);
return imageFile;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mWebView = (WebView) findViewById(R.id.activity_main_webview);
WebSettings webSettings = mWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
mWebView.getSettings().setAllowFileAccess(true);
mWebView.loadUrl("http://site.ru");
mWebView.setWebViewClient(new WebViewClient() {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return false;
}
});
mWebView.setWebChromeClient(new WebChromeClient() {
// For Android 5.0
public boolean onShowFileChooser(WebView view, ValueCallback<Uri[]> filePath, WebChromeClient.FileChooserParams fileChooserParams) {
// Double check that we don't have any existing callbacks
if (mFilePathCallback != null) {
mFilePathCallback.onReceiveValue(null);
}
mFilePathCallback = filePath;
Intent takePictureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
// Create the File where the photo should go
File photoFile = null;
try {
photoFile = createImageFile();
takePictureIntent.putExtra("PhotoPath", mCameraPhotoPath);
} catch (IOException ex) {
// Error occurred while creating the File
Log.e(TAG, "Unable to create Image File", ex);
}
// Continue only if the File was successfully created
if (photoFile != null) {
mCameraPhotoPath = "file:" + photoFile.getAbsolutePath();
takePictureIntent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, Uri.fromFile(photoFile));
} else {
takePictureIntent = null;
}
}
Intent contentSelectionIntent = new Intent(Intent.ACTION_GET_CONTENT);
contentSelectionIntent.addCategory(Intent.CATEGORY_OPENABLE);
contentSelectionIntent.setType("image/*;video/*");
Intent[] intentArray;
if (takePictureIntent != null) {
intentArray = new Intent[]{takePictureIntent};
} else {
intentArray = new Intent[0];
}
Intent chooserIntent = new Intent(Intent.ACTION_CHOOSER);
chooserIntent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, false);
chooserIntent.putExtra(Intent.EXTRA_INTENT, contentSelectionIntent);
chooserIntent.putExtra(Intent.EXTRA_TITLE, "Image Chooser");
chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, intentArray);
startActivityForResult(chooserIntent, INPUT_FILE_REQUEST_CODE);
return true;
}
// openFileChooser for Android 3.0+
public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType) {
mUploadMessage = uploadMsg;
// Create AndroidExampleFolder at sdcard
// Create AndroidExampleFolder at sdcard
File imageStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "AndroidExampleFolder");
if (!imageStorageDir.exists()) {
// Create AndroidExampleFolder at sdcard
imageStorageDir.mkdirs();
}
// Create camera captured image file path and name
File file = new File(imageStorageDir + File.separator + "IMG_" + String.valueOf(System.currentTimeMillis()) + ".jpg");
mCapturedImageURI = Uri.fromFile(file);
// Camera capture image intent
final Intent captureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
captureIntent.putExtra(MediaStore.EXTRA_OUTPUT, mCapturedImageURI);
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("image/*;video/*");
// Create file chooser intent
Intent chooserIntent = Intent.createChooser(i, "Image Chooser");
// Set camera intent to file chooser
chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Parcelable[]{captureIntent});
// On select image call onActivityResult method of activity
startActivityForResult(chooserIntent, FILECHOOSER_RESULTCODE);
}
// openFileChooser for Android < 3.0
public void openFileChooser(ValueCallback<Uri> uploadMsg) {
openFileChooser(uploadMsg, "");
}
//openFileChooser for other Android versions
public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
openFileChooser(uploadMsg, acceptType);
}
});
}
@Override
public boolean onKeyDown(int keyCode, @NonNull KeyEvent event){
String webUrl = mWebView.getUrl();
if(event.getAction() == KeyEvent.ACTION_DOWN){
switch(keyCode){
case KeyEvent.KEYCODE_BACK:
if(mWebView.canGoBack()){
if((webUrl.contains("url"))){
new AlertDialog.Builder(this).setTitle("Attention")
.setIcon(R.mipmap.ic_launcher)
.setMessage("Are you sure?")
.setPositiveButton("yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
finish();
}
}).setNegativeButton("no", null).show();
}
else
if((webUrl.contains("url"))){
Toast.makeText(this, "нажмите X кнопку.",
Toast.LENGTH_SHORT).show();
}
else
if((webUrl.contains("url")||(webUrl.contains("file:///android_asset/error_page.html")||webUrl.contains("url")))) {
new AlertDialog.Builder(this).setTitle("Attention")
.setIcon(R.mipmap.ic_launcher)
.setMessage("Are you sure?")
.setPositiveButton("yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
finish();
}
}).setNegativeButton("no", null).show();
}else {
mWebView.goBack();
}
}else {
new AlertDialog.Builder(this).setTitle("Attention")
.setIcon(R.mipmap.ic_launcher)
.setMessage("Are you sure?")
.setPositiveButton("yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
finish();
}
}).setNegativeButton("no", null).show();
}
return true;
}
}
return super.onKeyDown(keyCode, event);
}
}
清单
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.application">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:logo="@mipmap/ic_launcher"
android:label="Application"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:screenOrientation="portrait"
android:theme="@style/Theme.AppCompat.NoActionBar">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
</manifest>
答案 0 :(得分：0)
Android Marshmallow（6.0）之后，您还需要在运行时询问特殊权限（文件读取/写入）。 点击此链接 https://developer.android.com/training/permissions/requesting.html#java
之前，Android 6.0，
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
这曾经有用，但6.0以后却没有。
答案 1 :(得分：0)
问题是应用程序在4.1,4.2,4.3 orroids上工作得很好，它适用于5,6,7甚至8个android，但是在android 6的控制下的一个特定设备上，它不想工作文件上传
它有时会在这些Android版本上运行。它不会一直有效。
我们看到消息“mFilePathCallback == null”
当您的应用在后台时，您的流程已终止。这是完全正常的。如果在开始的活动位于前台时进行配置更改，则应该会出现相同的症状。在任何一种情况下，当控件返回到您的所有内容时，您最终会使用新活动，因此您的字段（例如mFilePathCallback）将为null。