java - 在 WebView 上选择文件上传时未获取文件路径

标签 java android

我正在尝试制作一个网页的 WebView 应用程序,用户可以将文件(图像)上传到表单并提交。 但是,网络应用程序工作正常,但无法通过 input type="file" 字段选择任何文件并提交。

我确实对此 issues like 进行了其他堆栈查询,但不幸的是我仍然需要有关此特定问题的帮助。

我的代码如下:

import androidx.appcompat.app.AppCompatActivity;

import android.annotation.TargetApi;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.webkit.ValueCallback;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;


import android.widget.Toast;
import android.os.Handler;


public class MainActivity extends AppCompatActivity {
    private static final int REQUEST_SELECT_FILE = 100;
    private ValueCallback<Uri> mUploadMessage;
    private ValueCallback<Uri[]> uploadMessage;
    private WebView webView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        webView = findViewById(R.id.webviewid);
        webView.setWebViewClient(new WebViewClient());
        webView.loadUrl("website url");
        webView.getSettings().setJavaScriptEnabled(true);
        webView.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
        webView.getSettings().setDomStorageEnabled(true);
        webView.setWebChromeClient(new WebChromeClient() {
            @TargetApi(Build.VERSION_CODES.LOLLIPOP)
            public boolean onShowFileChooser(WebView mWebView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {
                if (uploadMessage != null) {
                    uploadMessage.onReceiveValue(null);
                    uploadMessage = null;
                }
                uploadMessage = filePathCallback;
                Intent intent = fileChooserParams.createIntent();
                try {
                    startActivityForResult(intent, REQUEST_SELECT_FILE);
                } catch (ActivityNotFoundException e) {
                    uploadMessage = null;
                    Toast.makeText(getApplicationContext(), "Cannot Open File Chooser", Toast.LENGTH_LONG).show();
                    return false;
                }
                return true;
            }
        });
    }

    private boolean doubleBackToExitPressedOnce = false;

    @Override
    protected void onResume() {
        super.onResume();
        // .... other stuff in my onResume ....
        this.doubleBackToExitPressedOnce = false;
    }

    @Override
    public void onBackPressed() {
        if (doubleBackToExitPressedOnce) {
            super.onBackPressed();
            return;
        }

        if(webView.canGoBack()){
            webView.goBack();
        }

        this.doubleBackToExitPressedOnce = true;
        Toast.makeText(this, "Press again to exit", Toast.LENGTH_SHORT).show();

        new Handler().postDelayed(new Runnable() {

            @Override
            public void run() {
                doubleBackToExitPressedOnce=false;
            }
        }, 2000);
    }


}

文件无法上传,因为选择后输入字段中没有返回文件路径。

非常感谢任何帮助..

最佳答案

所以,经过几个小时在 androdi studio 中阅读文章..我终于找到了解决方案。

希望这对像我这样的人有帮助。

AndoridManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.suman.demo">
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.CALL_PHONE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission>
    <uses-permission  android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:usesCleartextTraffic="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

MainActivity.Java

package com.package.name;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import android.Manifest;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
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.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
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.Toast;

import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class MainActivity extends AppCompatActivity {

    private final static int FCR = 1;
    WebView webView;
    private String mCM;
    private ValueCallback<Uri> mUM;
    private ValueCallback<Uri[]> mUMA;
    private ValueCallback<Uri> mUploadMessage;
    private Uri mCapturedImageURI = null;
    private ValueCallback<Uri[]> mFilePathCallback;
    private String mCameraPhotoPath;
    private static final int INPUT_FILE_REQUEST_CODE = 1;
    private static final int FILECHOOSER_RESULTCODE = 1;
    private static final String TAG = MainActivity.class.getSimpleName();

    @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);
                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();
                    if (dataString != null) {
                        results = new Uri[]{Uri.parse(dataString)};
                    }
                }
            }
            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;
    }
    @SuppressLint({"SetJavaScriptEnabled", "WrongViewCast"})
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        webView = findViewById(R.id.webview_sample);
        if (Build.VERSION.SDK_INT >= 23 && (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED || ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)) {
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.CAMERA}, 1);
        }
        assert webView != null;

        WebSettings webSettings = webView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webSettings.setAllowFileAccess(true);
        webView.getSettings().setSupportZoom(true);
        webView.getSettings().setBuiltInZoomControls(true);

        if (Build.VERSION.SDK_INT >= 21) {
            webSettings.setMixedContentMode(0);
            webView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
        } else if (Build.VERSION.SDK_INT >= 19) {
            webView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
        } else if (Build.VERSION.SDK_INT < 19) {
            webView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
        }
        webView.setWebViewClient(new Callback());
        webView.loadUrl("website name goes here");


        webView.setWebChromeClient(new WebChromeClient() {


            private File createImageFile() throws IOException {

                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;

            }
            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(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(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/*");
                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_INTENT, contentSelectionIntent);
                chooserIntent.putExtra(Intent.EXTRA_TITLE, "Image Chooser");
                chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, intentArray);
                startActivityForResult(chooserIntent, INPUT_FILE_REQUEST_CODE);
                return true;
            }
            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/*");
                // 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);
            }
            public void openFileChooser(ValueCallback<Uri> uploadMsg,
                                        String acceptType,
                                        String capture) {
                openFileChooser(uploadMsg, acceptType);
            }

        });

    }


    public class Callback extends WebViewClient {
        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
            Toast.makeText(getApplicationContext(), "Failed loading app!", Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater myMenuInflater = getMenuInflater();
        myMenuInflater.inflate(R.menu.super_menu, menu);
        return super.onCreateOptionsMenu(menu);
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {

            case R.id.myMenuOne:
                onBackPressed();
                break;

            case R.id.myMenuTwo:
                GoForward();
                break;

        }
        return true;
    }
    private void GoForward() {
        if (webView.canGoForward()) {
            webView.goForward();
        } else {
            Toast.makeText(this, "Can't go further!", Toast.LENGTH_SHORT).show();
        }
    }
    @Override
    public void onBackPressed() {
        if (webView.canGoBack()) {
            webView.goBack();
        }
    }
}

Super_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context="com.filechooser.file.MainActivity">

    <item
        android:id="@+id/myMenuOne"
        android:icon="@drawable/ic_arrow_back_black_24dp"
        android:title="Item"
        app:showAsAction="always" />

    <item
        android:id="@+id/myMenuTwo"
        android:icon="@drawable/ic_arrow_forward_black_24dp"
        android:title="Item"
        app:showAsAction="always" />

</menu>

感谢那些花时间检查我的查询的人。 很乐意提供帮助。

关于java - 在 WebView 上选择文件上传时未获取文件路径,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/62486471/

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