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问题:

在WebView中从相机或画廊上传图像

郭乐湛
2023-03-14

此应用程序中的WebView会打开一个带有上载按钮的页面。

下面是一个代码块,可以打开一个对话框从gallery或camera上传图像。

在我的活动中,我有:

 private WebView wv;  

//make HTML upload button work in 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;        
  }  
 }  

在onCreate中,我有以下内容:

    wv.setWebChromeClient(new WebChromeClient()  {
        private Uri imageUri;   

        public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType )  {      
             File imageStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "MyApp");
            // Create the storage directory if it does not exist
            if (! imageStorageDir.exists()){
                imageStorageDir.mkdirs();                  
            }
            File file = new File(imageStorageDir + File.separator + "IMG_" + String.valueOf(System.currentTimeMillis()) + ".jpg");  
            imageUri = Uri.fromFile(file); 

            final List<Intent> cameraIntents = new ArrayList<Intent>();
            final Intent captureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
            final PackageManager packageManager = getPackageManager();
            final List<ResolveInfo> listCam = packageManager.queryIntentActivities(captureIntent, 0);
            for(ResolveInfo res : listCam) {
                final String packageName = res.activityInfo.packageName;
                final Intent i = new Intent(captureIntent);
                i.setComponent(new ComponentName(res.activityInfo.packageName, res.activityInfo.name));
                i.setPackage(packageName);
                i.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
                cameraIntents.add(i);

            }


            mUploadMessage = uploadMsg; 
            Intent i = new Intent(Intent.ACTION_GET_CONTENT);  
            i.addCategory(Intent.CATEGORY_OPENABLE);  
            i.setType("image/*"); 
            Intent chooserIntent = Intent.createChooser(i,"Image Chooser");
            chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, cameraIntents.toArray(new Parcelable[]{}));
            MainActivity.this.startActivityForResult(chooserIntent,  FILECHOOSER_RESULTCODE); 
        }

文件浏览器和图库正在按预期工作。问题是,当我用相机拍照时,它没有上载到“选择文件”选项中,该选项显示状态“未选择文件”。

选择相机时:

使用相机拍摄快照:出现返回和检查选项。

关于选择检查标记:

文件未上传:(在“选择文件”选项中)

预期:

我检查了我是否有适当的写作权限,因此生成了一个名为“MyApp”的目录,并将图片存储在其中(如果在点击网页上的上传按钮后调用相机拍摄)。

在点击复选标记后,如何通过编程告诉应用程序选择从相机(存储在MyApp目录中)拍摄的照片?

共有3个答案

康秋月
2023-03-14

更新6/18:这似乎不适用于Android4.2.1的三星银河S2。这在4.1.2的HTC One X上运行良好。请注意。

我也遇到了同样的问题。问题是这样的,我是如何解决的。

问题:

openFileChooser被调用时,回调对象ValueCallback

修正:

修复包括执行一些javascript,所以在webview上启用javascript。基本上,如果我们丢失了前一个对象,我们会得到另一个回调对象。

我们需要创建一个布尔字段“mUploadFileOnLoad”和三个字段。

    private int mReturnCode;
    private int mResultCode;
    private Intent mResultIntent;
    private boolean mUploadFileOnLoad = false;

当我们从摄像头返回活动时,将调用onActivityResult。如果活动被重建,则mUploadMessage为空。因此,我们将参数保存到字段中,并将mUploadFileOnLoad设置为true并返回。其他部分非常重要。

    @Override
    protected void onActivityResult(int requestCode, 
                                    int resultCode,
                                    Intent intent) 
    {  
      //if the callback object has been recycled      
      if(null==mUploadMessage)
      {
        //Save the result
        mReturnCode = requestCode;
        mResultCode = resultCode;
        mResultIntent = intent;
        //remember to invoke file upload using Javascript
        mUploadFileOnLoad = true;
        return;
      }else
        mUploadFileOnLoad = false;
      //rest of the code
    }

此解决方案的重要部分位于WebViewClientWebChromeClient

    new WebChromeClient() {

        //Other overloaded functions

        //See http://stackoverflow.com/a/15423907/375093 for full explanation
        //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) {
            //If we lost the callback object
            if(mUploadFileOnLoad)
            {
                mUploadMessage = uploadMsg;
                //use the saved result objects to invoke onActivityResult
                onActivityResult(mReturnCode, mResultCode, mResultIntent);
                return;
            }
         //Rest of the code....
         }

        new WebViewClient() {
        @Override
        public void onPageFinished(WebView view, String url) {
            if(mUploadFileOnLoad)
            {
               webview.loadUrl("javascript:document.getElementById('my_file').click()");
            }
        }

在上面,my_file

<input type="file" id="my_file">

总之,我们所做的是——当我们没有回调对象时,我们保存从其他活动接收的数据,并将mUploadFileOnLoad设置为true,然后等待页面加载。当页面加载时,我们使用Javascript来调用文件选择器,从而得到一个回调对象。因为我们已经有了结果,所以我们调用activityresult并返回。onActivityResult现在有一个来自webview的回调。

祖波光
2023-03-14

我假设实际调用onActivityResult方法,但第三个参数Intent-Intent为空。这似乎是Nexus手机的一个缺陷。

但是您可以将输出图像uri保存到私有变量中,并使用它而不是意图:

private Uri imageUri;

private void showAttachmentDialog(ValueCallback<Uri> uploadMsg) {
    this.mUploadMessage = uploadMsg;

    File imageStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "TestApp");
    if (!imageStorageDir.exists()) {
        imageStorageDir.mkdirs();
    }
    File file = new File(imageStorageDir + File.separator + "IMG_" + String.valueOf(System.currentTimeMillis()) + ".jpg");
    this.imageUri = Uri.fromFile(file); // save to the private variable

    final Intent captureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
    captureIntent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);

    Intent i = new Intent(Intent.ACTION_GET_CONTENT);
    i.addCategory(Intent.CATEGORY_OPENABLE);
    i.setType("image/*");

    Intent chooserIntent = Intent.createChooser(i, "Image Chooser");
    chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Parcelable[] { captureIntent });

    this.startActivityForResult(chooserIntent, FILECHOOSER_RESULTCODE);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
    if (requestCode == FILECHOOSER_RESULTCODE) {
        if (null == this.mUploadMessage) {
            return;
        }

        Uri result;
        if (resultCode != RESULT_OK) {
            result = null;
        } else {
            result = intent == null ? this.imageUri : intent.getData(); // retrieve from the private variable if the intent is null
        }

        this.mUploadMessage.onReceiveValue(result);
        this.mUploadMessage = null;
    }
}

在这段代码中,我将imageUri变量添加到活动中,并在两种方法中使用它。

蒋哲
2023-03-14

在苦苦挣扎之后,我找到了一个代码,可以从galley和5.0设备上获取文件

    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 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;
}

这是初始化和设置webview

     mWebView= (WebView) findViewById(R.id.webview);
        mWebView.getSettings().setJavaScriptEnabled(true);
        mWebView.getSettings().setPluginState(WebSettings.PluginState.OFF);
        mWebView.getSettings().setLoadWithOverviewMode(true);
        mWebView.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);
        mWebView.getSettings().setUseWideViewPort(true);
        mWebView.getSettings().setUserAgentString("Android Mozilla/5.0 AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30");
        mWebView.getSettings().setAllowFileAccess(true);
        mWebView.getSettings().setAllowFileAccess(true);
        mWebView.getSettings().setAllowContentAccess(true);
        mWebView.getSettings().supportZoom();
        mWebView.loadUrl(Common.adPostUrl);

        mWebView.setWebViewClient(new WebViewClient() {
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                // do your handling codes here, which url is the requested url
                // probably you need to open that url rather than redirect:
                if ( url.contains(".pdf")){
                    Intent intent = new Intent(Intent.ACTION_VIEW);
                    intent.setDataAndType(Uri.parse(url), "application/pdf");
                    try{
                        view.getContext().startActivity(intent);
                    } catch (ActivityNotFoundException e) {
                        //user does not have a pdf viewer installed
                    }
                } else {
                    mWebView.loadUrl(url);
                }
                return false; // then it is not handled by default action
            }


            @Override
            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {

Log.e("error",description);
            }


            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {        //show progressbar here

                super.onPageStarted(view, url, favicon);
            }

            @Override
            public void onPageFinished(WebView view, String url) {
          //hide progressbar here

            }

        });
        mWebView.setWebChromeClient(new ChromeClient());

这是我的ChomeClient()方法

public class ChromeClient extends 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(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(Common.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;

    }

    // 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/*");

        // 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);
    }

}

//下面是我的onActivityResult方法,用于处理来自图库或相机的数据

@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;
}

这是打开摄像头所需的权限

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.CAMERA2" /> // for new versions api 21+
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />

注意:我的代码也包含运行3.0的设备的代码,但我从未测试过它们,上面的代码适用于Lollipop、Marshmallow和牛轧糖模拟器。还有一件事,如果你看到Android系统的图标代替相机,这意味着你的设备中有许多应用程序可以用来处理相机。

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