我正在尝试在Android Studio中创建一个测验。因此，我想实现一个ListView，它在TextView中显示问题，并以Buttons的形式显示答案。
需要多个布局，因为问题可以有两个，三个或四个答案（按钮）。所以在每一行都应该有一个TextView，取决于答案2,3或4个按钮。
到目前为止，这是我的CustomAdapter。问题是这只适用于一个TextView，我不知道如何使用Buttons。
public class CustomAdapter extends ArrayAdapter {
private QuizItem[] items;
@Override
public int getViewTypeCount() {
return 3;
}
@Override
public int getItemViewType(int position) {
return items[position].getCategory();
}
public CustomAdapter(Context context, int question, QuizItem[] items) {
super(context, question, items);
this.items = items;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder = null;
QuizItem quizItem = items[position];
int quizItemType = getItemViewType(position);
if (convertView == null) {
if (quizItemType == Config.CATEGORY_TWO_ANSWERS) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.two_answers, null);
} else if (quizItemType == Config.CATEGORY_THREE_ANSWERS) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.three_answers, null);
}
else{
convertView = LayoutInflater.from(getContext()).inflate(R.layout.four_answers, null);
}
TextView textView = (TextView) convertView.findViewById(R.id.textView);
viewHolder = new ViewHolder(textView);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.getText().setText(quizItem.getQuestion());
return convertView;
}}
这是我的主类，我用for循环创建了一些演示日期：
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = (ListView) findViewById(R.id.simpleListView);
final QuizItem[] itemArray = new QuizItem[10];
int toggle = 0;
for(int i = 0; i < itemArray.length; i++){
if(toggle == 0){
itemArray[i] = new QuizItem("Question " + i, "Answer A", "Answer B");
toggle = 1;
}
else if(toggle == 1){
itemArray[i] = new QuizItem("Question " + i, "Answer A", "Answer B", "Answer C");
toggle = 2;
}
else{
itemArray[i] = new QuizItem("Question " + i, "Answer A", "Answer B", "Answer C", "Answer D");
toggle = 0;
}
}
CustomAdapter customAdapter = new CustomAdapter(this, R.id.textView, itemArray);
listView.setAdapter(customAdapter);
}}
那么如何将答案文本放在按钮上并显示正确数量的按钮？ 我非常感谢每一个信息！
编辑：这是LogCat
03-28 14:58:48.564 12092-12092/adonis.quiz D/dalvikvm﹕ Late-enabling CheckJNI
03-28 14:58:48.564 12092-12092/adonis.quiz D/dalvikvm﹕ Try to disable coredump for pid 12092
03-28 14:58:48.564 12092-12092/adonis.quiz D/dalvikvm﹕ Process 12092 nice name: adonis.quiz
03-28 14:58:48.564 12092-12092/adonis.quiz D/dalvikvm﹕ Extra Options: not specified
03-28 14:58:48.684 12092-12092/adonis.quiz W/dalvikvm﹕ VFY: unable to find class referenced in signature (Landroid/view/SearchEvent;)
03-28 14:58:48.684 12092-12092/adonis.quiz I/dalvikvm﹕ Could not find method android.view.Window$Callback.onSearchRequested, referenced from method android.support.v7.view.WindowCallbackWrapper.onSearchRequested
03-28 14:58:48.684 12092-12092/adonis.quiz W/dalvikvm﹕ VFY: unable to resolve interface method 14571: Landroid/view/Window$Callback;.onSearchRequested (Landroid/view/SearchEvent;)Z
03-28 14:58:48.684 12092-12092/adonis.quiz D/dalvikvm﹕ VFY: replacing opcode 0x72 at 0x0002
03-28 14:58:48.684 12092-12092/adonis.quiz I/dalvikvm﹕ Could not find method android.view.Window$Callback.onWindowStartingActionMode, referenced from method android.support.v7.view.WindowCallbackWrapper.onWindowStartingActionMode
03-28 14:58:48.684 12092-12092/adonis.quiz W/dalvikvm﹕ VFY: unable to resolve interface method 14575: Landroid/view/Window$Callback;.onWindowStartingActionMode (Landroid/view/ActionMode$Callback;I)Landroid/view/ActionMode;
03-28 14:58:48.684 12092-12092/adonis.quiz D/dalvikvm﹕ VFY: replacing opcode 0x72 at 0x0002
03-28 14:58:48.714 12092-12092/adonis.quiz I/dalvikvm﹕ Could not find method android.content.res.TypedArray.getChangingConfigurations, referenced from method android.support.v7.widget.TintTypedArray.getChangingConfigurations
03-28 14:58:48.714 12092-12092/adonis.quiz W/dalvikvm﹕ VFY: unable to resolve virtual method 463: Landroid/content/res/TypedArray;.getChangingConfigurations ()I
03-28 14:58:48.714 12092-12092/adonis.quiz D/dalvikvm﹕ VFY: replacing opcode 0x6e at 0x0002
03-28 14:58:48.724 12092-12092/adonis.quiz I/dalvikvm﹕ Could not find method android.content.res.TypedArray.getType, referenced from method android.support.v7.widget.TintTypedArray.getType
03-28 14:58:48.724 12092-12092/adonis.quiz W/dalvikvm﹕ VFY: unable to resolve virtual method 485: Landroid/content/res/TypedArray;.getType (I)I
03-28 14:58:48.724 12092-12092/adonis.quiz D/dalvikvm﹕ VFY: replacing opcode 0x6e at 0x0002
03-28 14:58:48.804 12092-12092/adonis.quiz D/CA/getType﹕ 5
03-28 14:58:48.804 12092-12092/adonis.quiz D/CA/getType﹕ 5
03-28 14:58:48.814 12092-12092/adonis.quiz D/AndroidRuntime﹕ Shutting down VM
03-28 14:58:48.814 12092-12092/adonis.quiz W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x430f2140)
03-28 14:58:48.824 12092-12092/adonis.quiz E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: adonis.quiz, PID: 12092
java.lang.NullPointerException
at adonis.quiz.CustomAdapter.getView(CustomAdapter.java:65)
at android.widget.AbsListView.obtainView(AbsListView.java:2312)
at android.widget.ListView.measureHeightOfChildren(ListView.java:1263)
at android.widget.ListView.onMeasure(ListView.java:1175)
at android.view.View.measure(View.java:16772)
at android.widget.RelativeLayout.measureChild(RelativeLayout.java:689)
at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:473)
at android.view.View.measure(View.java:16772)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5139)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135)
at android.view.View.measure(View.java:16772)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5139)
at android.support.v7.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:391)
at android.view.View.measure(View.java:16772)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5139)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
at android.view.View.measure(View.java:16772)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5139)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1404)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:695)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
at android.view.View.measure(View.java:16772)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5139)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2294)
at android.view.View.measure(View.java:16772)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1936)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1133)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1315)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1020)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5762)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:771)
at android.view.Choreographer.doCallbacks(Choreographer.java:574)
at android.view.Choreographer.doFrame(Choreographer.java:544)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:757)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:149)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:609)
at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：0)
You should create an inner ViewHolder class and define buttons and textview like this
Class ViewHolder
{
public static Button b1;
public static Button b2;
public static Button b3;
public static Button b4;
public static Textview t1;
}
Then modify the code like this
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder = null;
QuizItem quizItem = items[position];
int quizItemType = getItemViewType(position);
if (convertView == null) {
if (quizItemType == Config.CATEGORY_TWO_ANSWERS) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.two_answers, null);
viewHolder.t1=(TextView)convertView.findviewbyid(R.id.textview);
viewHolder.b1=(Button)convertView.findviewbyid(R.id.button);
viewHolder.b2=(Button)convertView.findviewbyid(R.id.button2);
} else if (quizItemType == Config.CATEGORY_THREE_ANSWERS) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.three_answers, null);
viewHolder.t1=(TextView)convertView.findviewbyid(R.id.textview);
viewHolder.b1=(Button)convertView.findviewbyid(R.id.button);
viewHolder.b2=(Button)convertView.findviewbyid(R.id.button2);
viewHolder.b3=(Button)convertView.findviewbyid(R.id.button23);
}
else{
convertView = LayoutInflater.from(getContext()).inflate(R.layout.four_answers, null);
viewHolder.t1=(TextView)convertView.findviewbyid(R.id.textview);
viewHolder.b1=(Button)convertView.findviewbyid(R.id.button);
viewHolder.b2=(Button)convertView.findviewbyid(R.id.button2);
viewHolder.b3=(Button)convertView.findviewbyid(R.id.button3);
viewHolder.b4=(Button)convertView.findviewbyid(R.id.button4);
}
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
//SET DATA ACCORDING TO LAYOUT
viewHolder.t1.setText(quizItem.getQuestion());
viewHolder.b1.setText(quizItem.getAnswer());
viewHolder.b2.setText(quizItem.getAnswer());
viewHolder.b3.setText(quizItem.getAnswer());
viewHolder.b4.setText(quizItem.getAnswer());
return convertView;
}}
答案 1 :(得分：0)
/ ------------------- QuizItem Model ------------------ /
public class QuizItem {
public String strQues = "";
public int iNoOfAns = 0;
public String strAns1 = "";
public String strAns2 = "";
public String strAns3 = "";
public String strAns4 = "";
public QuizItem (int noOFAns,String ques,String ans1,String ans2,String ans3,String ans4)
{
this.iNoOfAns = noOFAns;
this.strQues = ques;
this.strAns1 = ans1;
this.strAns2 = ans2;
this.strAns3 = ans3;
this.strAns4 = ans4;
}
}
在创建数组时进行一些更改，我添加了no。 of ans参数 -
final QuizItem[] itemArray = new QuizItem[10];
int toggle = 0;
for(int i = 0; i < itemArray.length; i++){
if(toggle == 0){
itemArray[i] = new QuizItem(2,"Question " + i, "Answer A", "Answer B","","");
toggle = 1;
}
else if(toggle == 1){
itemArray[i] = new QuizItem(3,"Question " + i, "Answer A", "Answer B", "Answer C","");
toggle = 2;
}
else{
itemArray[i] = new QuizItem(4,"Question " + i, "Answer A", "Answer B", "Answer C", "Answer D");
toggle = 0;
}
}
/ ------------------- CustomAdapter ------------------------- /
public class CustomAdapter extends ArrayAdapter<QuizItem> {
private QuizItem[] items;
Context mContext;
public CustomAdapter(Context context, int resource, QuizItem[] objects) {
super(context, resource, objects);
mContext = context;
items = objects;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
QuizItem quizItem = items[position];
int quizItemType = quizItem.iNoOfAns;
LayoutInflater inflator = ((android.app.Activity) mContext)
.getLayoutInflater();
if (quizItemType == 2) {
convertView = inflator.inflate(R.layout.temp_ans_two, parent,false);
TextView textView = (TextView) convertView.findViewById(R.id.tv_ques);
textView.setText(quizItem.strQues);
Button button1 = (Button)convertView.findViewById(R.id.button1);
button1.setText(quizItem.strAns1);
Button button2 = (Button)convertView.findViewById(R.id.button2);
button2.setText(quizItem.strAns2);
} else if (quizItemType ==3) {
convertView = inflator.inflate(R.layout.temp_ans_three, parent,false);
TextView textView = (TextView) convertView.findViewById(R.id.tv_ques);
textView.setText(quizItem.strQues);
Button button1 = (Button)convertView.findViewById(R.id.button1);
button1.setText(quizItem.strAns1);
Button button2 = (Button)convertView.findViewById(R.id.button2);
button2.setText(quizItem.strAns2);
Button button3 = (Button)convertView.findViewById(R.id.button3);
button3.setText(quizItem.strAns3);
}
else{
convertView = inflator.inflate(R.layout.temp_ans_four, parent,false);
TextView textView = (TextView) convertView.findViewById(R.id.tv_ques);
textView.setText(quizItem.strQues);
Button button1 = (Button)convertView.findViewById(R.id.button1);
button1.setText(quizItem.strAns1);
Button button2 = (Button)convertView.findViewById(R.id.button2);
button2.setText(quizItem.strAns2);
Button button3 = (Button)convertView.findViewById(R.id.button3);
button3.setText(quizItem.strAns3);
Button button4 = (Button)convertView.findViewById(R.id.button4);
button4.setText(quizItem.strAns4);
}
return convertView;
}}
答案 2 :(得分：0)
这是使用ViewHolder更新的CustomAdapter
public class CustomAdapter extends ArrayAdapter<QuizItem> {
private QuizItem[] items;
Context mContext;
public CustomAdapter(Context context, int resource, QuizItem[] objects) {
super(context, resource, objects);
mContext = context;
items = objects;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
QuizItem quizItem = items[position];
int quizItemType = quizItem.iNoOfAns;
LayoutInflater inflator = ((android.app.Activity) mContext)
.getLayoutInflater();
ViewHolder holder = null;
if (quizItemType == 2) {
convertView = inflator.inflate(R.layout.temp_ans_two, parent,false);
holder = new ViewHolder();
holder.textView = (TextView) convertView.findViewById(R.id.tv_ques);
holder.textView.setText(quizItem.strQues);
holder.button1 = (Button)convertView.findViewById(R.id.button1);
holder.button1.setText(quizItem.strAns1);
holder.button2 = (Button)convertView.findViewById(R.id.button2);
holder.button2.setText(quizItem.strAns2);
convertView.setTag(holder);
} else if (quizItemType ==3) {
convertView = inflator.inflate(R.layout.temp_ans_three, parent,false);
holder = new ViewHolder();
holder.textView = (TextView) convertView.findViewById(R.id.tv_ques);
holder.textView.setText(quizItem.strQues);
holder.button1 = (Button)convertView.findViewById(R.id.button1);
holder.button1.setText(quizItem.strAns1);
holder.button2 = (Button)convertView.findViewById(R.id.button2);
holder.button2.setText(quizItem.strAns2);
holder.button3 = (Button)convertView.findViewById(R.id.button3);
holder.button3.setText(quizItem.strAns3);
convertView.setTag(holder);
}
else{
convertView = inflator.inflate(R.layout.temp_ans_four, parent,false);
holder = new ViewHolder();
holder.textView = (TextView) convertView.findViewById(R.id.tv_ques);
holder.textView.setText(quizItem.strQues);
holder.button1 = (Button)convertView.findViewById(R.id.button1);
holder.button1.setText(quizItem.strAns1);
holder.button2 = (Button)convertView.findViewById(R.id.button2);
holder.button2.setText(quizItem.strAns2);
holder.button3 = (Button)convertView.findViewById(R.id.button3);
holder.button3.setText(quizItem.strAns3);
holder.button4 = (Button)convertView.findViewById(R.id.button4);
holder.button4.setText(quizItem.strAns4);
convertView.setTag(holder);
}
return convertView;
}
static class ViewHolder {
TextView textView;
Button button1;
Button button2;
Button button3;
Button button4;
}
}