我正在编写一个Android代码，如果用户选择一个特定的单选按钮，然后单击另一个按钮，则应打开一个新页面。另外，将一个微调器的值传递给另一个页面。当我执行我的代码时，应用程序崩溃。代码如下：
public class LeaveApp extends Activity {
private TextView Output1,Output2;
EditText e1;
private Button changeDate1,changeDate2,btn1;
int flag1=0,flag2=0;
private int year;
private int month;
private int day;
private Spinner spinner2;
static final int DATE_PICKER_ID1 = 1111;
static final int DATE_PICKER_ID2 = 1110;
// RadioButton rb1,rb2;
RadioGroup rg2;
String locationSet = null;
String strLocation = null;
Location arrLocation;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.leaveapp);
Output1 = (TextView) findViewById(R.id.textView7);
Output2= (TextView) findViewById(R.id.textView8);
changeDate1 = (Button) findViewById(R.id.button2);
changeDate2 = (Button) findViewById(R.id.button3);
spinner2=(Spinner) findViewById(R.id.spinner2);
btn1=(Button) findViewById(R.id.button1);
e1=(EditText) findViewById(R.id.editText1);
addItemsOnSpinner2();
rg2=(RadioGroup) findViewById(R.id.radiogroup2);
rg2.setOnCheckedChangeListener(new OnCheckedChangeListener()
{
@Override
public void onCheckedChanged(RadioGroup arg0, int arg1) {
// TODO Auto-generated method stub
switch(arg1)
{
case R.id.radioButton5:
flag1=1;
break;
case R.id.radioButton6:
flag2=1;
break;
}
}
});
spinner2.setOnItemSelectedListener(new MySpinnerSelectedListener());
// Get current date by calender
/*final Calendar c = Calendar.getInstance();
year = c.get(Calendar.YEAR);
month = c.get(Calendar.MONTH);
day = c.get(Calendar.DAY_OF_MONTH);*/
final Calendar c = Calendar.getInstance();
year=c.YEAR;
month=c.MONTH+1;
day=c.DAY_OF_MONTH;
// Button listener to show date picker dialog
changeDate1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// On button click show datepicker dialog
showDialog(DATE_PICKER_ID1);
}
});
changeDate2.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// On button click show datepicker dialog
showDialog(DATE_PICKER_ID2);
}
});
btn1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if(e1.getText().length()==0 || (flag1==0 && flag2==0))
{
Toast.makeText(getBaseContext(), "Please Enter all the fields!!",Toast.LENGTH_LONG).show();
}
else if(flag1==1)
{
Intent i=new Intent(LeaveApp.this,TestSelect.class);
i.putExtra("data1", spinner2.getSelectedItem().toString());
startActivity(i);
}
}
});
}
public void addItemsOnSpinner2() {
// TODO Auto-generated method stub
spinner2=(Spinner) findViewById(R.id.spinner2);
List<String> list2 = new ArrayList<String>();
list2.add("I");
list2.add("II");
list2.add("III");
list2.add("IV");
list2.add("V");
list2.add("VI");
list2.add("VII");
list2.add("VIII");
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item,list2);
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner2.setAdapter(dataAdapter);
}
@Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case DATE_PICKER_ID1:
// set date picker for current date
return new DatePickerDialog(this, pickerListener1, year, month,day);
case DATE_PICKER_ID2:
// set date picker for current date
return new DatePickerDialog(this, pickerListener2, year, month,day);
}
return null;
}
private DatePickerDialog.OnDateSetListener pickerListener1 = new DatePickerDialog.OnDateSetListener() {
// when dialog box is closed, below method will be called.
@Override
public void onDateSet(DatePicker view, int selectedYear,
int selectedMonth, int selectedDay) {
year = selectedYear;
month = selectedMonth;
day = selectedDay;
// Show selected date
/* Output1.setText(new StringBuilder().append(month + 1)
.append("-").append(day).append("-").append(year)
.append(" "));*/
Output1.setText(new StringBuilder().append(day).append("-").append(month + 1)
.append("-").append(year).append(" "));
}
};
private DatePickerDialog.OnDateSetListener pickerListener2 = new DatePickerDialog.OnDateSetListener() {
// when dialog box is closed, below method will be called.
@Override
public void onDateSet(DatePicker view, int selectedYear,
int selectedMonth, int selectedDay) {
year = selectedYear;
month = selectedMonth;
day = selectedDay;
// Show selected date
Output2.setText(new StringBuilder().append(month + 1)
.append("-").append(day).append("-").append(year)
.append(" "));
}
};
}
public class TestSelect extends Activity {
private Spinner spinner3,spinner2;
private Button btn4;
CharSequence[] options;
boolean[] selections;
String sem;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.testselect);
//spinner3=(Spinner) findViewById(R.id.spinner3);
spinner2=(Spinner) findViewById(R.id.spinner2);
Intent in=getIntent();
sem=in.getStringExtra("data1");
//addItemsOnSpinner3();
addItemsOnButton();
//System.out.println(sem);
btn4=(Button) findViewById(R.id.button4);
btn4.setOnClickListener(new ButtonClickHandler() );
}
public class ButtonClickHandler implements View.OnClickListener {
public void onClick( View view ) {
showDialog( 0 );
}
}
private void addItemsOnButton() {
if(sem.equals("III"))
{
options=new CharSequence[]{"DSPD","CAO","BDP"};
selections = new boolean[ options.length ];
}
else if(sem.equals("IV"))
{
options=new CharSequence[] {"TOFCS","OOP","OS"};
selections = new boolean[ options.length ];
}
else if(sem.equals("V"))
{
options=new CharSequence[] {"MI","CG","SP"};
selections = new boolean[ options.length ];
}
else //if(spinner2.getSelectedItem()=="VI")
{
options=new CharSequence[] {"DAA","DBMS","ICWS"};
selections = new boolean[ options.length ];
}
}
@Override
protected Dialog onCreateDialog( int id )
{
return
new AlertDialog.Builder( this )
.setTitle( "SUBJECTS" )
.setMultiChoiceItems( options, selections, new DialogSelectionClickHandler() )
.setPositiveButton( "OK", new DialogButtonClickHandler() )
.create();
}
public class DialogSelectionClickHandler implements DialogInterface.OnMultiChoiceClickListener
{
public void onClick( DialogInterface dialog, int clicked, boolean selected )
{
Log.i( "ME", options[ clicked ] + " selected: " + selected );
}
}
public class DialogButtonClickHandler implements DialogInterface.OnClickListener
{
public void onClick( DialogInterface dialog, int clicked )
{
switch( clicked )
{
case DialogInterface.BUTTON_POSITIVE:
printSelectedSubjects();
break;
}
}
private void printSelectedSubjects() {
// TODO Auto-generated method stub
for( int i = 0; i < options.length; i++ ){
Log.i( "ME", options[ i ] + " selected: " + selections[i] );
}
}
}
}
点击按钮，它应该从LeaveApp到TestSelect选择特定的radiobutto。请帮忙。
leaveapp.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:baselineAligned="true"
android:orientation="vertical"
android:layout_marginLeft="26dp"
android:layout_marginTop="20dp">
<ScrollView
android:id="@+id/scrollView1"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="380dp"
android:orientation="vertical" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="LEAVE TYPE"
android:textAppearance="?android:attr/textAppearanceMedium" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<RadioGroup
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/radiogroup2" >
<RadioButton
android:id="@+id/radioButton5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TEST"
android:layout_marginTop="10dp" />
<RadioButton
android:id="@+id/radioButton6"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CASUAL"
android:layout_marginTop="10dp" />
</RadioGroup>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="SEM"
android:textAppearance="?android:attr/textAppearanceMedium"
android:layout_marginTop="10dp" />
<Spinner
android:id="@+id/spinner2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="50dp" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="REASON"
android:layout_marginTop="10dp"
android:textAppearance="?android:attr/textAppearanceMedium" />
<EditText
android:id="@+id/editText1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:layout_marginTop="10dp"
android:inputType="textPostalAddress" >
<requestFocus />
</EditText>
</LinearLayout>
<TextView
android:id="@+id/textView4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="LEAVE DURATION"
android:layout_marginTop="10dp"
android:textAppearance="?android:attr/textAppearanceMedium" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="@+id/textView5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="FROM"
android:layout_marginTop="10dp"
android:textAppearance="?android:attr/textAppearanceMedium" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="SELECT" />
<TextView
android:id="@+id/textView7"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/button2"
android:layout_alignBottom="@+id/button2"
android:layout_marginLeft="26dp"
android:layout_toRightOf="@+id/textView5"
android:text=""
android:textAppearance="?android:attr/textAppearanceMedium" />
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginTop="10dp">
<TextView
android:id="@+id/textView6"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="50dp"
android:text="TO"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="@+id/textView8"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_marginLeft="38dp"
android:layout_toRightOf="@+id/textView6"
android:text=""
android:textAppearance="?android:attr/textAppearanceMedium" />
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:text="SELECT" />
</RelativeLayout>
</RelativeLayout>
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="100dp"
android:layout_marginTop="20dp"
android:text="NEXT" />
</LinearLayout>
</ScrollView>
</LinearLayout>
logcat
11-09 00:51:26.302: D/AndroidRuntime(1483): Shutting down VM
11-09 00:51:26.302: W/dalvikvm(1483): threadid=1: thread exiting with uncaught exception (group=0xb4b16b90)
11-09 00:51:26.392: E/AndroidRuntime(1483): FATAL EXCEPTION: main
11-09 00:51:26.392: E/AndroidRuntime(1483): Process: com.ara.quickaccess, PID: 1483
11-09 00:51:26.392: E/AndroidRuntime(1483): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.ara.quickaccess/com.ara.quickaccess.TestSelect}: java.lang.NullPointerException
11-09 00:51:26.392: E/AndroidRuntime(1483): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2102)
11-09 00:51:26.392: E/AndroidRuntime(1483): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
11-09 00:51:26.392: E/AndroidRuntime(1483): at android.app.ActivityThread.access$700(ActivityThread.java:135)
11-09 00:51:26.392: E/AndroidRuntime(1483): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
11-09 00:51:26.392: E/AndroidRuntime(1483): at android.os.Handler.dispatchMessage(Handler.java:102)
11-09 00:51:26.392: E/AndroidRuntime(1483): at android.os.Looper.loop(Looper.java:137)
11-09 00:51:26.392: E/AndroidRuntime(1483): at android.app.ActivityThread.main(ActivityThread.java:4998)
11-09 00:51:26.392: E/AndroidRuntime(1483): at java.lang.reflect.Method.invokeNative(Native Method)
11-09 00:51:26.392: E/AndroidRuntime(1483): at java.lang.reflect.Method.invoke(Method.java:515)
11-09 00:51:26.392: E/AndroidRuntime(1483): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
11-09 00:51:26.392: E/AndroidRuntime(1483): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
11-09 00:51:26.392: E/AndroidRuntime(1483): at dalvik.system.NativeStart.main(Native Method)
11-09 00:51:26.392: E/AndroidRuntime(1483): Caused by: java.lang.NullPointerException
11-09 00:51:26.392: E/AndroidRuntime(1483): at com.ara.quickaccess.TestSelect.<init>(TestSelect.java:28)
11-09 00:51:26.392: E/AndroidRuntime(1483): at java.lang.Class.newInstanceImpl(Native Method)
11-09 00:51:26.392: E/AndroidRuntime(1483): at java.lang.Class.newInstance(Class.java:1208)
11-09 00:51:26.392: E/AndroidRuntime(1483): at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
11-09 00:51:26.392: E/AndroidRuntime(1483): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2093)
11-09 00:51:26.392: E/AndroidRuntime(1483): ... 11 more
答案 0 :(得分：0)
请检查EditText＆＃34; e1＆＃34;的对象如
e1=(EditText) findViewById(R.id.textView1);
textView1是TextView或EditTex t。
根据您的logcat，ID textView1不是EditText所以只需替换
e1=(EditText) findViewById(R.id.textView1);
到
e1=(TextView)findViewById(R.id.textView1);
或将ID textView1设为EditText