当我按照错误消息运行我的应用程序时，它会给出：
不幸的是 appName 已停止错误
我有以下 MainActivity.java 文件：
package com.example.hello_world;
import android.os.Bundle;
import android.app.Activity;
import android.app.Dialog;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.TextView;
import android.widget.Toast;
import android.view.View.OnClickListener;
public class MainActivity extends Activity implements OnCheckedChangeListener {
Button btnSubmit,b2;
RadioButton rb1,rb2;
EditText etFirstName,etLastName;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnSubmit=(Button)findViewById(R.id.btnSubmit);
rb1.setOnCheckedChangeListener(new OnCheckedChangeListener() {
btnSubmit.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch(v.getId())
{
case R.id.btnSubmit:
boolean didWork=true;
try
{
String fName=((EditText) findViewById(R.id.etFirstName)).getText().toString();
String LName=((EditText) findViewById(R.id.etLastNam)).getText().toString();
Toast msg1 = Toast.makeText(getBaseContext(),
fName, Toast.LENGTH_LONG);
msg1.show();
HNT entry=new HNT(MainActivity.this);
entry.open();
Toast msg2 = Toast.makeText(getBaseContext(),
fName, Toast.LENGTH_LONG);
msg2.show();
entry.createEntry(fName,LName);
entry.close();
break;
}
catch(Exception e)
{
didWork=false;
Toast msg1 = Toast.makeText(getBaseContext(),
"Catch Failed"+e.getMessage(), Toast.LENGTH_LONG);
msg1.show();
}
finally
{
if(didWork)
{
Toast msg1 = Toast.makeText(getBaseContext(),
"Sucess", Toast.LENGTH_LONG);
msg1.show();
}
else
{
Toast msg1 = Toast.makeText(getBaseContext(),
"Failed", Toast.LENGTH_LONG);
msg1.show();
}
}
}
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public void onCheckedChanged(CompoundButton arg0, boolean arg1) {
// TODO Auto-generated method stub
}
}
xml文件：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
style="@style/AppTheme"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView
android:id="@+id/tvFName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginTop="34dp"
android:text="First Name"
android:textAppearance="?android:attr/textAppearanceLarge" />
<EditText
android:id="@+id/etFirstName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/tvFName"
android:layout_alignBottom="@+id/tvFName"
android:layout_alignParentRight="true"
android:layout_toRightOf="@+id/tvFName"
android:inputType="textPersonName" />
<EditText
android:id="@+id/etLastNam"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/etFirstName"
android:layout_below="@+id/etFirstName"
android:layout_marginLeft="13dp"
android:layout_marginTop="43dp"
android:ems="10"
android:inputType="textPersonName" />
<TextView
android:id="@+id/TextView01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/etLastNam"
android:layout_alignLeft="@+id/tvFName"
android:text="Last Name"
android:textAppearance="?android:attr/textAppearanceLarge" />
<Button
android:id="@+id/btnSubmit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/etLastNam"
android:layout_alignParentBottom="true"
android:layout_marginBottom="74dp"
android:text="Submit" />
</RelativeLayout>
清单文件：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.hello_world"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="17"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.hello_world.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>