朴人博客

最近发现公司APP内嵌的网页点击上传图片没任何效果，查资料得知是Android安全限制，WebView内网页默认没有读取本地文件的权限。虽然网上有解决方案，但是由于Android版本几经波折，API签名大相径庭，想要完全兼容，要实现多个方法，为方便以后使用，简单记录一下。

首先，在使用WebView的页面，增加如下全局变量，方便回调使用：

private static final String FILE_CHOOSER = "选择操作";
private String mCM;
private ValueCallback<Uri> mUM;
private ValueCallback<Uri[]> mUMA;
private final static int FCR = 1;

然后覆盖onActivityResult方法，内部实现如下：

//解决android input[type=file] 无法选择图片
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
    super.onActivityResult(requestCode, resultCode, intent);
    if (Build.VERSION.SDK_INT >= 21) {
        Uri[] results = null;
        //Check if response is positive
        if (resultCode == Activity.RESULT_OK) {
            if (requestCode == FCR) {
                if (null == mUMA) {
                    return;
                }
                if (intent == null) {
                    //Capture Photo if no image available
                    if (mCM != null) {
                        results = new Uri[]{Uri.parse(mCM)};
                    }
                } else {
                    String dataString = intent.getDataString();
                    if (dataString != null) {
                        results = new Uri[]{Uri.parse(dataString)};
                    }
                }
            }
        }
        mUMA.onReceiveValue(results);
        mUMA = null;
    } else {
        if (requestCode == FCR) {
            if (null == mUM) return;
            Uri result = intent == null || resultCode != RESULT_OK ? null : intent.getData();
            mUM.onReceiveValue(result);
            mUM = null;
        }
    }
}

关键部分，继承WebChromeClient，并实现如下方法，最终调用WebView的setWebChromeClient方法：

//For Android 3.0+
public void openFileChooser(ValueCallback<Uri> uploadMsg) {
    mUM = uploadMsg;
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.addCategory(Intent.CATEGORY_OPENABLE);
    intent.setType("*/*");
    startActivityForResult(Intent.createChooser(intent, FILE_CHOOSER), FCR);
}
// For Android 3.0+, above method not supported in some android 3+ versions, in such case we use this
public void openFileChooser(ValueCallback uploadMsg, String acceptType) {
    mUM = uploadMsg;
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.addCategory(Intent.CATEGORY_OPENABLE);
    intent.setType("*/*");
    startActivityForResult(Intent.createChooser(intent, FILE_CHOOSER), FCR);
}
//For Android 4.1+
public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
    mUM = uploadMsg;
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.addCategory(Intent.CATEGORY_OPENABLE);
    intent.setType("*/*");
    startActivityForResult(Intent.createChooser(intent, FILE_CHOOSER), FCR);
}
//For Android 5.0+
public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, WebChromeClient.FileChooserParams fileChooserParams) {
    if (mUMA != null) {
        mUMA.onReceiveValue(null);
    }
    mUMA = filePathCallback;
    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
        File photoFile = null;
        try {
            photoFile = createImageFile();
            takePictureIntent.putExtra("PhotoPath", mCM);
        } catch (IOException ex) {
            Log.e(TAG, "Image file creation failed", ex);
        }
        if (photoFile != null) {
            mCM = "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("*/*");
    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, FILE_CHOOSER);
    chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, intentArray);
    startActivityForResult(chooserIntent, FCR);
    return true;
}
// Create an image file
private File createImageFile() throws IOException {
    @SuppressLint("SimpleDateFormat")
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    String imageFileName = "img_" + timeStamp + "_";
    File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
    return File.createTempFile(imageFileName, ".jpg", storageDir);
}

注：最后一步四个主要方法中，startActivityForResult实为WebView所在Activity的方法，这里因为我自己的WebView做了定制，实现直接写在Activity，并且定义了接口传入自定义的WebView内，这样分离了WebView与Activity的代码，如果你WebView没有做定制等，这里可以改为YourActivity.this.startActivityForResult，请悉知。