在公开课下我宣布了
int content = 0;
String content2;
这只适用于一行。我的问题是我想使用for获取所有行，但它给了我错误。如何将其转换为FOR LOOP？
ListView listview = getListView();
int position = 0;
View angelC = listview.getChildAt(position);
inputAnswer = (EditText)angelC.findViewById(R.id.inputAnswer);
correct_answer = (TextView)angelC.findViewById(R.id.correct_answer);
if(inputAnswer.getText().toString().equals(correct_answer.getText().toString()) ){
content = 0 + 1;
content2 = Integer.toString(content);
}else{
content = 0 + 0;
content2 = Integer.toString(content);
}
下面是我的for循环希望你会看到问题，因为我是android编程的新手。
for (int i = 0; i < listview.getAdapter().getCount(); i++) {
View angelC = listview.getChildAt(i);
inputAnswer = (EditText) angelC.findViewById(R.id.inputAnswer);
correct_answer = (TextView) angelC.findViewById(R.id.correct_answer);
if(inputAnswer.getText().toString().equals(correct_answer.getText().toString()) ){
content = 0 + 1;
content2 = Integer.toString(content);
}else{
content = 0 + 0;
content2 = Integer.toString(content);
}
}
这是我的LOGCAT
FATAL EXCEPTION: AsyncTask #2
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:299)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
at java.util.concurrent.FutureTask.run(FutureTask.java:239)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:856)
Caused by: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.EditText
at com.example.androidhive.AnswerQuestionActivity$PassProduct.doInBackground(AnswerQuestionActivity.java:158)
at com.example.androidhive.AnswerQuestionActivity$PassProduct.doInBackground(AnswerQuestionActivity.java:1)
at android.os.AsyncTask$2.call(AsyncTask.java:287)
at java.util.concurrent.FutureTask.run(FutureTask.java:234)
... 3 more
Skipped 494 frames! The application may be doing too much work on its main thread.
onDetachedFromWindow
Activity com.example.androidhive.AnswerQuestionActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{41803fa8 V.E..... R.....ID 0,0-220,114} that was originally added here
android.view.WindowLeaked: Activity com.example.androidhive.AnswerQuestionActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{41803fa8 V.E..... R.....ID 0,0-220,114} that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:454)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:235)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:73)
at android.app.Dialog.show(Dialog.java:282)
at com.example.androidhive.AnswerQuestionActivity$PassProduct.onPreExecute(AnswerQuestionActivity.java:123)
at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586)
at android.os.AsyncTask.execute(AsyncTask.java:534)
at android.view.View.performClick(View.java:4421)
at android.view.View$PerformClick.run(View.java:18190)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:175)
at android.app.ActivityThread.main(ActivityThread.java:5279)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
at dalvik.system.NativeStart.main(Native Method)
Activity com.example.androidhive.AnswerQuestionActivity has leaked IntentReceiver com.immersion.android.haptics.HapticFeedbackManager$HapticFeedbackBroadcastReceiver@417bfa78 that was originally registered here. Are you missing a call to unregisterReceiver()?
android.app.IntentReceiverLeaked: Activity com.example.androidhive.AnswerQuestionActivity has leaked IntentReceiver com.immersion.android.haptics.HapticFeedbackManager$HapticFeedbackBroadcastReceiver@417bfa78 that was originally registered here. Are you missing a call to unregisterReceiver()?
1at android.app.LoadedApk$ReceiverDispatcher.<init>(LoadedApk.java:800)
at android.app.LoadedApk.getReceiverDispatcher(LoadedApk.java:601)
at android.app.ContextImpl.registerReceiverInternal(ContextImpl.java:1650)
at android.app.ContextImpl.registerReceiver(ContextImpl.java:1630)
at android.app.ContextImpl.registerReceiver(ContextImpl.java:1624)
at android.content.ContextWrapper.registerReceiver(ContextWrapper.java:430)
at com.immersion.android.haptics.HapticFeedbackManager.setupPackageBroadcastReceiver(HapticFeedbackManager.java:564)
at com.immersion.android.haptics.HapticFeedbackManager.<init>(HapticFeedbackManager.java:108)
at com.immersion.android.HapticFeedbackManagerProxy.initialize(HapticFeedbackManagerProxy.java:90)
at com.immersion.android.HapticFeedbackManagerProxy.access$100(HapticFeedbackManagerProxy.java:30)
at com.immersion.android.HapticFeedbackManagerProxy$1$1.run(HapticFeedbackManagerProxy.java:71)
at java.lang.Thread.run(Thread.java:856)
10-06 13:08:51.374: I/Process(14572): Sending signal. PID: 14572 SIG: 9
这是我的Java文件的所有代码。我只是想要，如果Edittext = Textview，得分将增加到1.我在使用FOR LOOP获取mysql中的所有行时遇到问题。
package com.example.androidhive;
public class AnswerQuestionActivity extends ListActivity {
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
JSONParser jsonParser = new JSONParser();
ArrayList<HashMap<String, String>> productsList;
//
EditText inputLastName, inputFirstName, inputYear, inputCourse, inputAge;
//list xml
EditText inputAnswer;
Button btnPass;
TextView correct_answer;
int content = 0;
String content2;
//OLD LOCAL ADDRESS 10.0.2.2
static String server = ((NewQuestionActivity)getActivity()).server;
private static String url_all_products = "http://"+server+"/android_quiz/get_all_products.php";
private static String url_pass_product = "http://"+server+"/android_quiz/pass_product.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private static final String TAG_PID = "pid";
private static final String TAG_QUESTION = "question";
private static final String TAG_SELECT_A = "select_a";
private static final String TAG_SELECT_B = "select_b";
private static final String TAG_SELECT_C = "select_c";
private static final String TAG_CORRECT_ANSWER = "correct_answer";
// products JSONArray
JSONArray products = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.student_listview);
//EditText
inputLastName = (EditText) findViewById(R.id.inputLastName);
inputFirstName = (EditText) findViewById(R.id.inputFirstName);
inputYear = (EditText) findViewById(R.id.inputYear);
inputCourse = (EditText) findViewById(R.id.inputCourse);
inputAge = (EditText) findViewById(R.id.inputAge);
// Hashmap for ListView
productsList = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllProducts().execute();
//TOAST MESSAGE ON START-UP
Toast.makeText(this, "Put the letter of your answer in the whitebox", Toast.LENGTH_LONG).show();
btnPass = (Button) findViewById(R.id.btnPass);
btnPass.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
new PassProduct().execute();
}
});
}
/**
* Background Async Task to Create new product
* */
class PassProduct extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(AnswerQuestionActivity.this);
pDialog.setMessage("Passing Answers..");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
* Passing product
*
* */
protected String doInBackground(String... args) {
String name = inputLastName.getText().toString() +" "+inputFirstName.getText().toString();
String year_course = inputYear.getText().toString() +" - "+ inputCourse.getText().toString();
String age = inputAge.getText().toString();
这个工作正常但只有一行。我把它作为评论，因为它正在发挥作用。
ListView listview = getListView();
//
// int position = 0;
// View angelC = listview.getChildAt(position);
// inputAnswer = (EditText)angelC.findViewById(R.id.inputAnswer);
// correct_answer = (TextView)angelC.findViewById(R.id.correct_answer);
// if(inputAnswer.getText().toString().equals(correct_answer.getText().toString()) ){
//
// content = 0 + 1;
// content2 = Integer.toString(content);
// }else{
//
// content = 0 + 0;
// content2 = Integer.toString(content);
// }
现在这是我的FOR LOOP让我头疼。
for (int i = 0; i < listview.getAdapter().getCount(); i++) {
View angelC = listview.getChildAt(i);
inputAnswer = (EditText) angelC.findViewById(R.id.inputAnswer);
correct_answer = (TextView) angelC.findViewById(R.id.correct_answer);
if(inputAnswer.getText().toString().equals(correct_answer.getText().toString()) ){
//INCREMENT THE SCORE
}else{
// NO INCREMENT
}
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("name", name));
params.add(new BasicNameValuePair("year_course", year_course));
params.add(new BasicNameValuePair("age", content2));
// getting JSON Object
// Note that create product url accepts POST method
JSONObject json = jsonParser.makeHttpRequest(url_pass_product,
"POST", params);
// check log cat fro response
Log.d("Create Response", json.toString());
// check for success tag
try {
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// successfully created product
Intent i = new Intent(getApplicationContext(), MainScreenActivity.class);
startActivity(i);
// closing this screen
finish();
} else {
// failed to create product
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog once done
pDialog.dismiss();
}
}
private static NewQuestionActivity getActivity() {
// TODO Auto-generated method stub
return null;
}
// Response from Edit Product Activity
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// if result code 100
if (resultCode == 100) {
// if result code 100 is received
// means user edited/deleted product
// reload this screen again
Intent intent = getIntent();
finish();
startActivity(intent);
}
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllProducts extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(AnswerQuestionActivity.this);
pDialog.setMessage("Loading products. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_PRODUCTS);
// looping through All Products
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_PID);
String question = c.getString(TAG_QUESTION);
String A = c.getString(TAG_SELECT_A);
String B = c.getString(TAG_SELECT_B);
String C = c.getString(TAG_SELECT_C);
String correct_answer = c.getString(TAG_CORRECT_ANSWER);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_PID, id);
map.put(TAG_QUESTION, question);
map.put(TAG_SELECT_A,"a. "+ A);
map.put(TAG_SELECT_B,"b. "+ B);
map.put(TAG_SELECT_C,"c. "+ C);
map.put(TAG_CORRECT_ANSWER, correct_answer);
// adding HashList to ArrayList
productsList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
Intent i = new Intent(getApplicationContext(),
NewQuestionActivity.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
AnswerQuestionActivity.this, productsList, R.layout.student_question,
new String[] { TAG_PID, TAG_QUESTION, TAG_SELECT_A,TAG_SELECT_B,TAG_SELECT_C,TAG_CORRECT_ANSWER },
new int[] { R.id.pid, R.id.question, R.id.choice_a, R.id.choice_b, R.id.choice_c, R.id.correct_answer});
// updating listview
setListAdapter(adapter);
}
});
}
}
}
答案 0 :(得分：1)
Caused by: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.EditText
首先，
更改
correct_answer = (EditText) angelC.findViewById(R.id.correct_answer);
到
correct_answer = (TextView) angelC.findViewById(R.id.correct_answer);
您必须查看xml中的元素，然后进行相应的转换。
答案 1 :(得分：0)
你犯了很多错误，我无法理解你到底想做什么。 首先这些意味着什么？
if(inputAnswer.getText().toString().equals(correct_answer.getText().toString()) ){
content = 0 + 1;
content2 = Integer.toString(content);
}else{
content = 0 + 0;
content2 = Integer.toString(content);
content and content2 = 始终 1和0.这与：
相同if(inputAnswer.getText().toString().equals(correct_answer.getText().toString()) ){
content2 = "1";
}else{
content2 = "0";
如果您想增加content使用content++
另外为什么correct_answer为TextView，后来为EditText ???
ListView listview = getListView();
int position = 0;
View angelC = listview.getChildAt(position);
inputAnswer = (EditText)angelC.findViewById(R.id.inputAnswer);
correct_answer = (TextView)angelC.findViewById(R.id.correct_answer);
if(inputAnswer.getText().toString().equals(correct_answer.getText().toString()) ){
content++;
content2 = Integer.toString(content);
}
要获得第二个位置，你必须增加它。在某处添加position++
最后你的for循环检查 xml中的correct_answer。是TextView还是EditText：
for (int i = 0; i < listview.getAdapter().getCount(); i++) {
View angelC = listview.getChildAt(i);
inputAnswer = (EditText) angelC.findViewById(R.id.inputAnswer);
correct_answer = (TextView) angelC.findViewById(R.id.correct_answer);
if(inputAnswer.getText().toString().equals(correct_answer.getText().toString()) ){
score++;//INCREMENT THE SCORE
}
// else{} //if you don't need to increment don't use else.