Question

我正在使用带有Theme.Dialog的Activity来执行我的AlertDialog，因为我正在尝试在BroadcastReceiver中使用此对话框，但是当我添加OnClickListener时，应用程序每次启动时都会崩溃。

代码：

package nyp.android.project;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class PasswordDialog extends Activity {

    private static final String TAG = "Logging Activity";
    //Context context;   
    Button login;
    EditText inputPassword;

    private static final int MY_PASSWORD_DIALOG_ID = 0;

    protected void onCreate(Bundle savedInstanceState) 
    {
        //this.context = context;
        super.onCreate(savedInstanceState);
        setContentView (R.layout.password_dialog);

        //SharedPreferences passwdfile = context.getSharedPreferences(    
        //        PhoneFinder.PASSWORD_PREF_KEY, 0); 

        //String correctSHA1 = passwdfile.getString(PhoneFinder.PASSWORD_PREF_KEY, null);

        login = (Button) findViewById(R.id.loginPassword);
        inputPassword = (EditText) findViewById(R.id.btnLogin);

        login.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
              Toast.makeText(PasswordDialog.this, "Hello World!", Toast.LENGTH_LONG).show();
            }
        });
        }

    }

logcat的：

07-25 12:27:30.354: D/AndroidRuntime(570): Shutting down VM
07-25 12:27:30.354: W/dalvikvm(570): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
07-25 12:27:30.364: E/AndroidRuntime(570): FATAL EXCEPTION: main
07-25 12:27:30.364: E/AndroidRuntime(570): java.lang.RuntimeException: Unable to start activity ComponentInfo{nyp.android.project/nyp.android.project.PasswordDialog}: java.lang.ClassCastException: android.widget.EditText
07-25 12:27:30.364: E/AndroidRuntime(570):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
07-25 12:27:30.364: E/AndroidRuntime(570):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
07-25 12:27:30.364: E/AndroidRuntime(570):  at android.app.ActivityThread.access$2300(ActivityThread.java:125)
07-25 12:27:30.364: E/AndroidRuntime(570):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
07-25 12:27:30.364: E/AndroidRuntime(570):  at android.os.Handler.dispatchMessage(Handler.java:99)
07-25 12:27:30.364: E/AndroidRuntime(570):  at android.os.Looper.loop(Looper.java:123)
07-25 12:27:30.364: E/AndroidRuntime(570):  at android.app.ActivityThread.main(ActivityThread.java:4627)
07-25 12:27:30.364: E/AndroidRuntime(570):  at java.lang.reflect.Method.invokeNative(Native Method)
07-25 12:27:30.364: E/AndroidRuntime(570):  at java.lang.reflect.Method.invoke(Method.java:521)
07-25 12:27:30.364: E/AndroidRuntime(570):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
07-25 12:27:30.364: E/AndroidRuntime(570):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
07-25 12:27:30.364: E/AndroidRuntime(570):  at dalvik.system.NativeStart.main(Native Method)
07-25 12:27:30.364: E/AndroidRuntime(570): Caused by: java.lang.ClassCastException: android.widget.EditText
07-25 12:27:30.364: E/AndroidRuntime(570):  at nyp.android.project.PasswordDialog.onCreate(PasswordDialog.java:38)
07-25 12:27:30.364: E/AndroidRuntime(570):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-25 12:27:30.364: E/AndroidRuntime(570):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
07-25 12:27:30.364: E/AndroidRuntime(570):  ... 11 more

XML：

<?xml version="1.0" encoding="utf-8"?>

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:orientation="vertical"
        android:padding="10dip" >


        <!--  Password Label -->
        <TextView
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="15dip"
            android:text="Password" />
        <!--  Password TextField -->

        <EditText
            android:id="@+id/loginPassword"
            android:layout_width="260dp"
            android:layout_height="wrap_content"
            android:password="true" />

        <!--  Login Button -->        
        <Button
            android:id="@+id/btnLogin"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dip"
            android:text="Login" />

    </LinearLayout>

Answer 1

java.lang.ClassCastException: android.widget.EditText

见上面的错误行，您尝试引用编辑文本，而不是按钮...

Answer 2

这是因为您将EditText的ID标识为Button的ID。所以尝试如下所示 -

login = (Button) findViewById(R.id.btnLogin);
inputPassword = (EditText) findViewById(R.id.loginPassword);

这是错误发生的确切位置。

Answer 3

无法从BroadcastReceiver类生成AlertDialog，请参阅

this

添加View.onClickListener时，带有主题对话框的自定义AlertDialog崩溃

3 个答案: