问题
I try to update information through java script code in Android side.
On Android version 4.3, it's work.
But Android version 4.4, it appeared these error, so can not update information.
[INFO:CONSOLE(1)] "Uncaught TypeError: Cannot set property 'value' of null", source: (1) I/chromium﹕ [INFO:CONSOLE(1)] "Uncaught TypeError: Cannot set property 'value' of null", source: (1) I/chromium﹕ [INFO:CONSOLE(1)] "Uncaught TypeError: Cannot call method 'submit' of null", source: (1)
I know from Android version 4.4, already used new Web View to support, but i don't know where is main issue.
People who know how to update information successfully via Java script code even on Android 4.4,
Please tell me,
Thanks you,
p/s : Codes
// Load Web View to update new SSID, Security Key, Security Mode
WebView mWv = new WebView(this);
// Simplest usage: note that an exception will NOT be thrown
// if there is an error loading this page (see below).
mWv.loadUrl("http://" + Constants.IP + "/cgi-bin/input");
mWv.getSettings().setJavaScriptEnabled(true);
mWv.getSettings().setDomStorageEnabled(true);
mWv.setWebChromeClient(new WebChromeClient());
mWv.setWebViewClient(new WebViewClient(){
public void onPageFinished(WebView mWv, String url) {
super.onPageFinished(mWv, url);
/**
* Pass parametes :
* - New SSID
* - New Security Key
* - Display raw picture
*/
// @"document.getElementsByName('%@')[0].value='%@'"
mWv.loadUrl("javascript:document.getElementById('wifi_ssid').value='" +
mEtSSID.getText().toString() + "'");
if (mEtSecurityKey.length() == 0
| Utils.checkValidatePassword(mEtSecurityKey, 8)) {
mWv.loadUrl("javascript:document.getElementById('wifi_key').value='" +
mEtSecurityKey.getText().toString() + "'");
if (mCbDisplayRawPicture.isChecked())
mWv.loadUrl(
"javascript:document.getElementById('displayraw').value='checked'");
else
mWv.loadUrl("javascript:document.getElementById('displayraw').value=''");
// @"document.forms['sendForm'].submit()"
mWv.loadUrl("javascript:document.getElementById('sendForm').submit()");
/**
* Also get new SSID and new Security Key in Card Setting page
*/
IS_BACK_FROM_CHANGE_SSID_AND_SCCURITY_KEY_TO_CARD_SETTING_PAGE = true;
/**
* Finish current Change SSID And Security Key after submit success
*/
finish();
} else
Toast.makeText(SettingAndReviewSettingPage.this,
getString(R.string.toast_your_password_is_case_sensitive),
Toast.LENGTH_SHORT).show();
}
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
});
SOLUTION
I surprised when I find out the solution. I need define the variables for Java script codes. Like following code & it worked.
mWv.setWebViewClient(new WebViewClient(){
public void onPageFinished(WebView mWv, String url) {
super.onPageFinished(mWv, url);
/**
* Pass parametes :
* - New SSID
* - New Security Key
* - Display raw picture
*/
// @"document.getElementsByName('%@')[0].value='%@'"
mWv.loadUrl("javascript:var x = document.getElementById('wifi_ssid').value = '" +
mEtSSID.getText().toString() + "';");
// need check password is correct or not
// - empty or minimum has 8 characters.
// - have both character & number in typed password
if ((mEtSecurityKey.length() == 0
| Utils.checkValidatePassword(mEtSecurityKey, 8)
& Utils.checkValidatePassword(mEtSecurityKey.getText().toString()))) {
mWv.loadUrl("javascript:var y = document.getElementById('wifi_key').value = '" +
mEtSecurityKey.getText().toString() + "';");
if (mCbDisplayRawPicture.isChecked())
mWv.loadUrl("javascript:var z = document.getElementById('displayraw').value='checked'");
else
mWv.loadUrl("javascript:var z = document.getElementById('displayraw').value=''");
// @"document.forms['sendForm'].submit()"
// mWv.loadUrl("javascript:console.log('sendForm: '+document.getElementById('sendForm').value);");
mWv.loadUrl("javascript:document.getElementById('sendForm').submit()");
/**
* Also get new SSID and new Security Key in Card Setting page
*/
IS_BACK_FROM_CHANGE_SSID_AND_SCCURITY_KEY_TO_CARD_SETTING_PAGE = true;
/**
* Finish current Change SSID And Security Key after submit success
*/
finish();
} else
Toast.makeText(
ChangeSSIDAndPasswordPage.this,
getString(R.string.toast_your_password_is_case_sensitive),
Toast.LENGTH_SHORT).show();
}
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
});
回答1:
The simple solution is to ensure the WebView has the following setting enabled:
WebView webView = new WebView(this); // this is the context
webView.getSettings().setDomStorageEnabled(true);
This allows the browser to store a DOM model of the page elements, so that Javascript can perform operations on it.
Hint: This works only from api 7.
回答2:
I surprised when I find out the solution. I need define the variables for Java script codes. Like following code javascript:var x = & it worked.
mWv.setWebViewClient(new WebViewClient(){
public void onPageFinished(WebView mWv, String url) {
super.onPageFinished(mWv, url);
/**
* Pass parametes :
* - New SSID
* - New Security Key
* - Display raw picture
*/
// @"document.getElementsByName('%@')[0].value='%@'"
mWv.loadUrl("javascript:var x = document.getElementById('wifi_ssid').value = '" +
mEtSSID.getText().toString() + "';");
// need check password is correct or not
// - empty or minimum has 8 characters.
// - have both character & number in typed password
if ((mEtSecurityKey.length() == 0
| Utils.checkValidatePassword(mEtSecurityKey, 8)
& Utils.checkValidatePassword(mEtSecurityKey.getText().toString()))) {
mWv.loadUrl("javascript:var y = document.getElementById('wifi_key').value = '" +
mEtSecurityKey.getText().toString() + "';");
if (mCbDisplayRawPicture.isChecked())
mWv.loadUrl("javascript:var z = document.getElementById('displayraw').value='checked'");
else
mWv.loadUrl("javascript:var z = document.getElementById('displayraw').value=''");
// @"document.forms['sendForm'].submit()"
// mWv.loadUrl("javascript:console.log('sendForm: '+document.getElementById('sendForm').value);");
mWv.loadUrl("javascript:document.getElementById('sendForm').submit()");
/**
* Also get new SSID and new Security Key in Card Setting page
*/
IS_BACK_FROM_CHANGE_SSID_AND_SCCURITY_KEY_TO_CARD_SETTING_PAGE = true;
/**
* Finish current Change SSID And Security Key after submit success
*/
finish();
} else
Toast.makeText(
ChangeSSIDAndPasswordPage.this,
getString(R.string.toast_your_password_is_case_sensitive),
Toast.LENGTH_SHORT).show();
}
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
});
回答3:
Simple solution:
wv.loadUrl("javascript:document.getElementById('xx').value='';void(0);");
To prevent browser from redirecting to a plain text version of the result of evaluating that JavaScript append the JavaScript string with void(0);
Reference: void operator
来源：https://stackoverflow.com/questions/27938209/uncaught-typeerror-cannot-set-property-value-of-null-in-android