小编Tec*_*Frk的帖子

我正在尝试为android中的单选按钮实现自定义图标.即我希望单选按钮图标是我自己选择的一个.我可以使用android:button单选按钮内的属性来做到这一点,但我没有在用户单击它时如何定义它.在我的应用程序中,当用户点击它没有任何反应.我也在这里遵循了这个指南.

I have 2 images :
 A. tire.png (When the radio button is not clicked)
 B. tireinvert.png (When the radio button is clicked)

我的RadioButton.xml文件:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    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="com.techfrk.customizeradiobutton.MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

     <RadioGroup
                android:id="@+id/newexprgrp"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" >

                <RadioButton
                android:id="@+id/tvllocrbtn"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:layout_marginLeft="20dp"
                android:layout_marginTop="40dp"
                android:text="Travelling Expense (Local)"
                />

                  <RadioButton
                android:id="@+id/tvloutrbtn"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:layout_marginLeft="20dp"
                android:layout_marginTop="15dp"
                android:text="Travelling Expense (Outstation)"

                 />

               <RadioButton
                android:id="@+id/phnexprbtn"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:layout_marginLeft="20dp"
                android:layout_marginTop="15dp"
                android:text="Phone Expense" …

我正在尝试为我的活动实现自定义适配器，该适配器将从两个ArrayList填充listview。但是，我对下一步该怎么办感到困惑？这是我的代码：

public class Offers extends Activity 
{
    ListView latesttrans;
    Boolean flagValue = false;

    ArrayList<String> listItems = new ArrayList<String>();
    ArrayList<String> listAddress = new ArrayList<String>();
    String[] addr;
    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_offers);
        latesttrans = (ListView) findViewById(R.id.listView1);

        Uri latesttransuri = Uri.parse("content://sms/inbox");
        Cursor latesttranscursor = getContentResolver().query(latesttransuri, new String[]{"_id","address","date","body"}, null, null, null);

        if(flagValue == false)
        {
            latesttranscursor.moveToFirst();
            flagValue = true;
        }

        String address = null,body = null;
        int i=0;

            while(latesttranscursor.moveToNext())
            {
                address=latesttranscursor.getString(1);
                long date = latesttranscursor.getLong(2);
                String sdate = millisToDate(date);
                body = …

我正在尝试为我的活动实现executeUpdate查询.但是我收到此错误:

java.lang.NullPointerException: Attempt to invoke virtual method 'void com.techfrk.fetchinboxsms.Database_CustomTransaction.executeUpdate(java.lang.String)' on a null object reference

这是我的代码:

public class AddTransaction extends Activity implements OnItemSelectedListener, View.OnClickListener, OnItemClickListener
{
    DateFormat formate = DateFormat.getDateInstance();
    Calendar calendar = Calendar.getInstance();

    ImageButton imgbtn_personal,imgbtn_debitCredit,imgbtn_transferAnother,imgbtn_incomeExpense,calendarimg;

    Button dialogButton;

    Database_CustomTransaction mydb1;

    Boolean personal_flag=true, debitCredit_flag=true, transferAccount=true, incomeExpense=true;

    String transaction_type = "No type selected !";
    public static final String list_prefs = "PreferencesFile";

    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_add_transaction);
        imgbtn_personal = (ImageButton) findViewById(R.id.personal_business);
        imgbtn_debitCredit = (ImageButton) findViewById(R.id.debit_credit_refund);
        imgbtn_transferAnother = (ImageButton) findViewById(R.id.transfer_another_acc);
        imgbtn_incomeExpense = …