when i try to launch my app everything work fine but when i open a class from the menu, it does not open. im new to android programming. Help me please..thank you
keep getting this message
Unfortunately, (App Name) has stopped."
Here is my java
package com.e_attendance;
import android.app.Activity;
import android.app.AlertDialog.Builder;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class ManageClass extends Activity implements OnClickListener
{
EditText editClassno;
Button btnAdd, btnDelete, btnModify, btnViewAll;
SQLiteDatabase db;
@Override
public void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.classdetail);
editClassno = (EditText) findViewById(R.id.editClassno);
btnAdd.setOnClickListener(this);
btnDelete.setOnClickListener(this);
btnModify.setOnClickListener(this);
btnViewAll.setOnClickListener(this);
db = openOrCreateDatabase("ClassDB", Context.MODE_PRIVATE, null);
db.execSQL("CREATE TABLE IF NOT EXISTS class (classno VARCHAR);");
}
@Override
public void onClick(View view) {
if (view == btnAdd) {
if (editClassno.getText().toString().trim().length() == 0)
{
showMessage("Error", "Enter a Class No please");
return;
}
db.execSQL("INSERT INTO class VALUES('" + editClassno.getText()
+ "');");
showMessage("Success", "Record added");
clearText();
}
if (view == btnDelete) {
if (editClassno.getText().toString().trim().length() == 0) {
showMessage("Error", "Please enter Classno");
return;
}
Cursor c = db.rawQuery("SELECT * FROM class WHERE classno='"
+ editClassno.getText() + "'", null);
if (c.moveToFirst()) {
db.execSQL("DELETE FROM class WHERE classno='"
+ editClassno.getText() + "'");
showMessage("Success", "Record Deleted");
} else {
showMessage("Error", "Invalid Classno");
}
clearText();
}
if (view == btnModify) {
if (editClassno.getText().toString().trim().length() == 0) {
showMessage("Error", "Please enter Classno");
return;
}
Cursor c = db.rawQuery("SELECT * FROM class WHERE classno='"
+ editClassno.getText() + "'", null);
if (c.moveToFirst()) {
db.execSQL("UPDATE class SET class WHERE classno='"
+ editClassno.getText() + "'");
showMessage("Success", "Record Modified");
} else {
showMessage("Error", "Invalid Clasno");
}
clearText();
}
if (view == btnViewAll) {
Cursor c = db.rawQuery("SELECT * FROM class", null);
if (c.getCount() == 0) {
showMessage("Error", "No records found");
return;
}
StringBuffer buffer = new StringBuffer();
while (c.moveToNext()) {
buffer.append("Classno: " + c.getString(0) + "\n");
;
}
showMessage("Classes No.", buffer.toString());
}
}
public void clearText() {
editClassno.setText("");
editClassno.requestFocus();
}
public void showMessage(String title, String message) {
Builder builder = new Builder(this);
builder.setCancelable(true);
builder.setTitle(title);
builder.setMessage(message);
builder.show();
}
}
my xml
<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/myLayout2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:stretchColumns="0" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_x="110dp"
android:layout_y="10dp"
android:text="Class Section" />
<Button
android:id="@+id/btnAdd"
android:layout_width="100dp"
android:layout_height="40dp"
android:layout_x="30dp"
android:layout_y="200dp"
android:text="@string/add" />
<Button
android:id="@+id/btnDelete"
android:layout_width="100dp"
android:layout_height="40dp"
android:layout_x="150dp"
android:layout_y="200dp"
android:text="@string/delete" />
<Button
android:id="@+id/btnModify"
android:layout_width="100dp"
android:layout_height="40dp"
android:layout_x="30dp"
android:layout_y="250dp"
android:text="@string/modify" />
<Button
android:id="@+id/btnViewAll"
android:layout_width="100dp"
android:layout_height="40dp"
android:layout_x="30dp"
android:layout_y="300dp"
android:text="@string/view_all" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_x="30dp"
android:layout_y="102dp"
android:text="Class_no" />
<EditText
android:id="@+id/editClassno"
android:layout_width="150dp"
android:layout_height="40dp"
android:layout_x="120dp"
android:layout_y="93dp"
android:ems="10"
android:inputType="number" />
</AbsoluteLayout>
android manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.e_attendance"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="16"
android:targetSdkVersion="16" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
-
<activity
android:name="com.e_attendance.HomeActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".SignUPActivity" />
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="com.e_attendance.STARTINGPOINT" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
<activity
android:name=".Menu"
android:label="@string/app_name" >
<intent-filter>
<action android:name="com.e_attendance.MENU" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
<activity
android:name=".OpenNotes"
android:label="@string/app_name" >
</activity>
<activity android:name=".NewText" >
</activity>
<activity
android:name=".ManageClass"
android:label="@string/app_name" >
</activity>
<activity
android:name=".ManageStudents"
android:label="@string/app_name" >
</activity>
</application>
</manifest>
