我搜查了我的案子，但是我无法在这里找到一个合适的答案新手，但仍然没有工作，所以请帮助我......
这是我的代码......
TextView TotalAmount;
int total_amount = 0;
RecyclerView dayrecyclerView;
List<Day_Details> DL;
Day_Adapter dayAdapter;
public static List<Day_Details> daysize;
TotalAmount = (TextView) findViewById(R.id.event_total);
TotalAmount.setText(String.valueOf(total_amount));
public void Day(List<Day_Details> dyl) {
//List<Day_Details>dayDetailsList
Log.i("day response length", "dayresponse length " + dyl.size());
if (dyl.size() > 0) {
daysize = dyl;
daylayout.setVisibility(LinearLayout.VISIBLE);
DL = new ArrayList<>();
dayAdapter = new Day_Adapter(this, DL);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this);
dayrecyclerView.setLayoutManager(layoutManager);
dayrecyclerView.setItemAnimator(new DefaultItemAnimator());
dayrecyclerView.setAdapter(dayAdapter);
dayrecyclerView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
return true;
}
});
for (int i = 0; i < dyl.size(); i++) {
String price = "₹ " + dyl.get(i).getDayPrice();
Day_Details DD = new Day_Details(dyl.get(i).getId(),
dyl.get(i).getDayTitle(), dyl.get(i).getDayDate(), price,
dyl.get(i).getDayContent());
Log.i(" Event_view ", "Day: Details "+DD.toString());
DL.add(DD);
}
dayAdapter.notifyDataSetChanged();
}
}
public void daychecker(Boolean ischecked,String id){
if(ischecked == true){
for (int i = 0; i <daysize.size(); i++) {
if(id == daysize.get(i).getId()){
String price = daysize.get(i).getDayPrice();
int amount = Integer.parseInt(price);
total_amount = total_amount + amount;
}
}
TotalAmount.setText("1234");
}else{
for (int i = 0; i <=daysize.size(); i++) {
if(id == String.valueOf(i)){
String price = daysize.get(i).getDayPrice();
int amount = Integer.parseInt(price);
total_amount = total_amount - amount;
TotalAmount.setText(String.valueOf(total_amount));
}
}
}
}
日子在recyclerview 当我选中复选框时，它会传递一个ID和价格 我必须在 textview （TotalAmount）中显示价格 所以当我点击复选框时，它显示错误为
04-25 11:27:29.366 9462-9462/com.appeonix.dithesh.doceventUI E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.appeonix.dithesh.doceventUI, PID: 9462
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at com.appeonix.doceventUI.Activity.UI.Event_View$override.daychecker(Event_View.java:258)
at com.appeonix.doceventUI.Activity.UI.Event_View$override.access$dispatch(Event_View.java)
at com.appeonix.doceventUI.Activity.UI.Event_View.daychecker(Event_View.java:0)
at com.appeonix.doceventUI.Activity.Holder.Day_Holder$1.onClick(Day_Holder.java:39)
at android.view.View.performClick(View.java:5184)
at android.widget.CompoundButton.performClick(CompoundButton.java:128)
at android.view.View$PerformClick.run(View.java:20910)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5942)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)
这是我的Oncreateview
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.event_view_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
sharedPreferences = getSharedPreferences("DocEventPreference", Context.MODE_PRIVATE);
memid = sharedPreferences.getString("DocId", null);
scrollView = (NestedScrollView) findViewById(R.id.Event_view_Scroll);
//team
teamrecyclerView = (RecyclerView) findViewById(R.id.team_recycler_view);
//gallery
galrecyclerView = (RecyclerView) findViewById(R.id.galleryrecycler_view);
//day
dayrecyclerView = (RecyclerView) findViewById(R.id.dayrecycler_view);
//details
About = (TextView) findViewById(R.id.abouttheevent);
//qrcode
imageView = (ImageView) findViewById(R.id.qrCode);
//register
TotalAmount = (TextView) findViewById(R.id.event_total);
TotalAmount.setText(String.valueOf(total_amount));
registerlay = (LinearLayout) findViewById(R.id.registerlayout);
button = (Button) findViewById(R.id.Event_reg_confirm_btn);
scrollView.post(new Runnable() {
public void run() {
scrollView.fullScroll(scrollView.FOCUS_UP);
}
});
events_details = new Events_Details();
events_details.setId(event_id);
eventitle = (TextView) findViewById(R.id.Event_Name);
Event_IMG = (ImageView) findViewById(R.id.backdrop);
//LinearLayout
eventgallerylayout = (LinearLayout)
findViewById(R.id.EventView_Gallery);
eventdetailslayout = (LinearLayout)
findViewById(R.id.EventView_Details);
daylayout = (LinearLayout) findViewById(R.id.EventDay_Details);
eventteamlayout = (LinearLayout) findViewById(R.id.EventView_Team);
eventQRlayout = (LinearLayout) findViewById(R.id.EventView_Qrcode);
// eventregisterlayout = (LinearLayout)
findViewById(R.id.EventView_Register);
eventdetailslayout.setVisibility(LinearLayout.GONE);
button.setVisibility(View.GONE);
eventteamlayout.setVisibility(LinearLayout.GONE);
daylayout.setVisibility(LinearLayout.GONE);
eventgallerylayout.setVisibility(LinearLayout.GONE);
// eventQRlayout.setVisibility(LinearLayout.GONE);
// eventregisterlayout.setVisibility(LinearLayout.GONE);
SingleEventJavaWebservice webservice = new SingleEventJavaWebservice(
Event_View.this, events_details, Event_View.this);
webservice.execute();
initCollapsingToolbar();
}
提前致谢...
答案 0 :(得分：0)
@Dithesh请您使用调试来检查您在该方法中初始化要分配的TextView值。另请检查String.valueOf（total_amount）返回正确的字符串值。
答案 1 :(得分：0)
textview的初始化应该在onCreate（）
中TotalAmount =（TextView）findViewById（R.id.event_total）;
导致错误的原因。
根据您更新的问题进行修改
初始化看起来很好，所以你应该检查布局文件＆＃39; event_view_main.xml＆＃39;如果它包含带有id＆＃39; event_total＆＃39;
的TextView答案 2 :(得分：0)
如果你没有初始化TextView，那么它会抛出一个空指针执行 您应该在创建活动时初始化TextView。
答案 3 :(得分：0)
请检查你的xml布局id＆＃34; event_total＆＃34;是否合适：
<tr />