此代码可用于棒棒糖（5.0），棉花糖（6.0），奥利奥（8.1.1），但不适用于奇巧（4.4）和牛轧糖（7.1.1）。
我确实在android版本的牛轧糖上调试了这段代码，然后我发现ValueCallback<Uri>引用对象mUMA在onActivityResult()方法中为null，但是这段代码在android版本的Lollipop，棉花糖，奥利奥（Oreo）。
活动课程
public class MainActivity extends AppCompatActivity {
private WebView webView;
public Uri imageUri;
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;
private String mCM = null;
private ValueCallback<Uri> mUM = null;
private ValueCallback<Uri[]> mUMA;
private final static int FCR = 1;
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case 1:
if (permissions.length != 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED &&
grantResults[1] == PackageManager.PERMISSION_GRANTED && grantResults[2] == PackageManager.PERMISSION_GRANTED) {
init();
}
}
}
public void init() {
webView.setWebViewClient(new MyWebViewClient());
webView.getSettings().setJavaScriptEnabled(true);
webView.getSettings().setLoadsImagesAutomatically(true);
webView.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
webView.getSettings().setJavaScriptEnabled(true);
webView.getSettings().setLoadWithOverviewMode(true);
webView.setScrollbarFadingEnabled(false);
webView.getSettings().setUserAgentString("Android Mozilla/5.0 AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30");
webView.getSettings().setPluginState(WebSettings.PluginState.ON_DEMAND);
webView.getSettings().setDomStorageEnabled(true);
webView.getSettings().setUseWideViewPort(true);
webView.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
webView.getSettings().setAllowFileAccess(true);
webView.getSettings().setAllowFileAccessFromFileURLs(true);
webView.getSettings().setAllowUniversalAccessFromFileURLs(true);
if (Build.VERSION.SDK_INT >= 21) {
webView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
webView.getSettings().setMixedContentMode(WebSettings.MIXED_CONTENT_ALWAYS_ALLOW);
}else if (Build.VERSION.SDK_INT >= 19) {
webView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
}else if (Build.VERSION.SDK_INT >= 14 && Build.VERSION.SDK_INT < 19) {
webView.requestFocus();
webView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}
//webView.loadUrl("http://www.linkfolo.com");
webView.loadUrl("file:///android_res/raw/index.html");
webView.setWebChromeClient(new WebChromeClient());
webView.setWebChromeClient(new WebChromeClient() {
//For Android 3.0+
public void openFileChooser(ValueCallback<Uri> uploadMsg) {
mUM = uploadMsg;
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("*/*");
MainActivity.this.startActivityForResult(Intent.createChooser(i, "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 i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("*/*");
MainActivity.this.startActivityForResult(
Intent.createChooser(i, "File Browser"),
FCR);
}
//For Android 4.1+
public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
mUM = uploadMsg;
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
i.setType("*/*");
MainActivity.this.startActivityForResult(Intent.createChooser(i, "File Chooser"), MainActivity.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(MainActivity.this.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, "Image Chooser");
chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, intentArray);
startActivityForResult(chooserIntent, FCR);
return true;
}
});
}
@SuppressLint({"SetJavaScriptEnabled", "WrongViewCast"})
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
webView = (WebView) findViewById(R.id.webview);
if (Build.VERSION.SDK_INT >= 23 && (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED ||
(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.READ_EXTERNAL_STORAGE, Manifest.permission.CAMERA}, 1);
}
init();
}
@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 (mUMA == null) {
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)};
}
}
}
}//WebChromeClient.FileChooserParams.parseResult(resultCode, data)
if (results != null) {
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;
}
}
}
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);
}
@Override
// Detect when the back button is pressed
public void onBackPressed() {
if (webView.canGoBack()) {
webView.goBack();
} else {
// Let the system handle the back button
super.onBackPressed();
}
}
class MyWebViewClient extends WebViewClient {
ProgressDialog progressDialog;
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
Toast.makeText(getApplicationContext(), "Failed loading app!", Toast.LENGTH_SHORT).show();
}
@Override
public boolean shouldOverrideUrlLoading(WebView view, String 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 = new ProgressDialog(MainActivity.this);
progressDialog.setMessage("Loading...");
progressDialog.show();
progressDialog.setCancelable(true);
}
}
// Called when all page resources loaded
public void onPageFinished(WebView view, String url) {
try {
// Close progressDialog
if (progressDialog.isShowing()) {
progressDialog.dismiss();
progressDialog = null;
}
} catch (Exception exception) {
exception.printStackTrace();
}
}
}
}