【发布时间】：2014-06-11 12:41:11
【问题描述】：
这是我的第一个 android 应用程序，第一页包含 2 个按钮，第一个按钮效果很好。当我单击第二个按钮时，应用程序停止并显示错误：android.widget,textView cannot be cast to android.widget,button
如果我尝试正确读取错误，它会告诉您：Caused by... 下面的行告诉您错误是在哪里引发的，它位于line 55 上的Login.onCreate() 中。据我所知，第 55 行是：
btnLogin = (Button) findViewById(R.id.btnFerme);
我已经检查了许多类似的问题，并且在他们清理项目或正确的 XML 布局后它就消失了。 我试过： -清洁项目。 -检查过的 XML 文件。 - 使用 XML onClick 属性创建另一个方法 它仍然没有工作。有人可以帮帮我吗？谢谢。
XML：
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/in" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:padding="10dip" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="10dip"
android:layout_marginTop="20dp"
android:text="Authentification"
android:textColor="#ffffff"
android:textSize="25sp"
android:typeface="serif" />
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_marginTop="20dp"
android:text="Login"
android:textColor="#3b3b3b"
android:textSize="20sp" />
<EditText
android:id="@+id/txt_login"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:hint="Entrer votre login"
android:inputType="textEmailAddress" />
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_marginTop="15dip"
android:text="Mot de passe"
android:textColor="#3b3b3b"
android:textSize="20sp"
android:textStyle="normal" />
<EditText
android:id="@+id/txt_mdp"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:hint="Entrer votre mot de passe"
android:inputType="textPassword" />
<Button
android:id="@+id/btnFerme"
android:layout_width="fill_parent"
android:layout_height="50dp"
android:layout_marginLeft="50dp"
android:layout_marginRight="50dp"
android:layout_marginTop="40dp"
android:text="Se connecter"
android:textSize="18sp" />
</LinearLayout>
</ScrollView>
编辑：
package com.example.gestionincidents;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import com.example.gestionincidents.Login;
import com.example.gestionincidents.R;
public class Login extends Activity {
private static final String strURL = "http://unfmtetouan.com/android_connect/utilisateur.php";
private EditText inputEmail;
private EditText inputPassword;
private Button btnLogin;
private ProgressDialog pDialog;
private AlertDialogManager alert = new AlertDialogManager();
private static final String ExtraLogin = "Login";
protected static final String ExtraUser = "UserKey";
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
inputEmail = (EditText) findViewById(R.id.txt_login);
inputPassword = (EditText) findViewById(R.id.txt_mdp);
btnLogin = (Button) findViewById(R.id.btnFerme);
btnLogin.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
new Compte().execute();
}
});
}
class Compte extends AsyncTask<String,String, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(Login.this);
pDialog.setMessage("Veuillez Patienter ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected String doInBackground(String... arg0) {
String result =null;
InputStream is = null;
StringBuilder sb = new StringBuilder();
ArrayList<NameValuePair> nameValuePairs=new ArrayList<NameValuePair> ();
nameValuePairs.add(new BasicNameValuePair("utilisateur",inputEmail.getText().toString()));
try{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(strURL);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
}catch(Exception exp){
Log.e("log_tag", "Error in http connection " + exp.toString());
}
try{
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result=sb.toString();
}catch(Exception exc){
Log.e("log_tag", "Error in http connection " + exc.toString());
}
String essai=result.substring(0, 4) ;
try {
if (result.matches("<br >")){
essai=result.substring(0, 2) ;
}
JSONArray jArray = new JSONArray(result);
int b=jArray.length();
JSONObject json_data = jArray.getJSONObject(0);
final String mot_pass = json_data.getString("mdp").toString();
final String login = json_data.getString("Login").toString();
final String idu = json_data.getString("id_utilisateur").toString();
new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
if (mot_pass.equals(inputPassword.getText().toString())){
Intent principale =new Intent(Login.this, afficher_incidents.class);
principale.putExtra(ExtraLogin, login);
principale.putExtra(ExtraUser, idu);
startActivity(principale);
finish();
}else {
runOnUiThread(new Runnable() {
public void run() {
alert.showAlertDialog(Login.this, ":(" , "Mot de Passe Incorrecte !" , false);
// hada howa l3adi Toast.makeText(getApplicationContext(), "Mots de Passe Incorrect", Toast.LENGTH_SHORT).show();
}
});
}
}
}).start();
}catch(JSONException e){
runOnUiThread(new Runnable() {
public void run() {
alert.showAlertDialog(Login.this, ":(" , "Login Incorrecte !" , false);
}
});
}
// TODO Auto-generated method stub
return null;
}
@Override
protected void onPostExecute(String file_url) {
// dismiss the dialog once done
pDialog.dismiss();
}
}}
编辑 2：
06-11 13:03:52.921: E/AndroidRuntime(5877): FATAL EXCEPTION: main
06-11 13:03:52.921: E/AndroidRuntime(5877): java.lang.RuntimeException: Unable to start activity ComponentInfo{org.catours.tourfinder/com.example.gestionincidents.Login}: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.Button
06-11 13:03:52.921: E/AndroidRuntime(5877): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2262)
06-11 13:03:52.921: E/AndroidRuntime(5877): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2316)
06-11 13:03:52.921: E/AndroidRuntime(5877): at android.app.ActivityThread.access$700(ActivityThread.java:158)
06-11 13:03:52.921: E/AndroidRuntime(5877): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1296)
06-11 13:03:52.921: E/AndroidRuntime(5877): at android.os.Handler.dispatchMessage(Handler.java:99)
06-11 13:03:52.921: E/AndroidRuntime(5877): at android.os.Looper.loop(Looper.java:176)
06-11 13:03:52.921: E/AndroidRuntime(5877): at android.app.ActivityThread.main(ActivityThread.java:5365)
06-11 13:03:52.921: E/AndroidRuntime(5877): at java.lang.reflect.Method.invokeNative(Native Method)
06-11 13:03:52.921: E/AndroidRuntime(5877): at java.lang.reflect.Method.invoke(Method.java:511)
06-11 13:03:52.921: E/AndroidRuntime(5877): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
06-11 13:03:52.921: E/AndroidRuntime(5877): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
06-11 13:03:52.921: E/AndroidRuntime(5877): at dalvik.system.NativeStart.main(Native Method)
06-11 13:03:52.921: E/AndroidRuntime(5877): Caused by: java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.Button
06-11 13:03:52.921: E/AndroidRuntime(5877): at com.example.gestionincidents.Login.onCreate(Login.java:55)
06-11 13:03:52.921: E/AndroidRuntime(5877): at android.app.Activity.performCreate(Activity.java:5326)
06-11 13:03:52.921: E/AndroidRuntime(5877): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1097)
06-11 13:03:52.921: E/AndroidRuntime(5877): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2225)
06-11 13:03:52.921: E/AndroidRuntime(5877): ... 11 more
【问题讨论】：
-
从模拟器或设备上卸载您的应用程序并重新安装。
-
我做了，但仍然显示相同的错误
-
那么你需要清理你的项目
-
我清洗了几次。并且每次都显示相同的东西
-
你试过删除gen和bin文件夹然后清理然后运行。
标签： android xml android-layout textview android-button