[英]can not use findViewById method in public void function
我在android中使用片段,我在這個片段中有一個帶有CustomersFragment
片段名稱的片段,我使用findViewById
方法,當我在onCreateView
上使用此方法沒問題時,但是當我在public void
函數中使用它有錯誤時,這是我的片段代碼在底部
package com.androiddeft.navigationdrawer.fragments;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import com.androiddeft.navigationdrawer.MyListAdapter;
import com.androiddeft.navigationdrawer.R;
import com.androiddeft.navigationdrawer.Employee;
import com.androiddeft.navigationdrawer.DatabaseHelper;
import com.androiddeft.navigationdrawer.constants.NavigationDrawerConstants;
import java.util.List;
public class CustomersFragment extends Fragment {
private Button btnSubmit;
private Button btnCancel;
private ListView listView;
private MyListAdapter adapter;
private EditText edtSearch, edtName, edtPhone, edtAddress;
private int seletcedEmployeeId;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActivity().setTitle(NavigationDrawerConstants.TAG_CUSTOMERS);
}
@Override
public View onCreateView(final LayoutInflater inflater, final ViewGroup container, final Bundle savedInstanceState) {
// Create the view from XML layout.
final View view = inflater.inflate(R.layout.fragment_customers, null);
// Perform additional configuration on layout components here.
Button btnAdd = (Button) view.findViewById(R.id.btn_add);
Button btnShowSearch = (Button) view.findViewById(R.id.btn_search);
Button btnCloseSearch = (Button) view.findViewById(R.id.btn_close_search);
Button btnDoSearch = (Button) view.findViewById(R.id.btn_do_search);
btnCancel = (Button) view.findViewById(R.id.btn_cancel);
btnSubmit = (Button) view.findViewById(R.id.btn_submit);
edtSearch = (EditText) view.findViewById(R.id.edt_search);
edtName = (EditText) view.findViewById(R.id.edt_employee_name);
edtPhone = (EditText) view.findViewById(R.id.edt_employee_phone);
edtAddress = (EditText) view.findViewById(R.id.edt_employee_address);
btnAdd.setOnClickListener(onAddClicked);
btnShowSearch.setOnClickListener(onShowSearchClicked);
btnCloseSearch.setOnClickListener(onCloseSearchClicked);
btnDoSearch.setOnClickListener(onDoSearchClicked);
btnCancel.setOnClickListener(onCancelbuttonClicked);
listView = (ListView) view.findViewById(R.id.listView);
refreshList();
return view;
}
private void refreshList() {
List<Employee> employees = new DatabaseHelper(this).getListOfEmployees();
adapter = new MyListAdapter(this, employees);
listView.setAdapter(adapter);
}
public void editEmployee(Employee employee) {
findViewById(R.id.lin_add_search).setVisibility(View.GONE);
findViewById(R.id.add_edit_employee).setVisibility(View.VISIBLE);
btnSubmit.setOnClickListener(onEditEmployeeSubmit);
edtName.setText(employee.getName());
edtPhone.setText(employee.getPhone());
edtAddress.setText(employee.getAddress());
seletcedEmployeeId = employee.getId();
}
private View.OnClickListener onAddClicked = new View.OnClickListener() {
@Override
public void onClick(View view) {
findViewById(R.id.lin_add_search).setVisibility(View.GONE);
findViewById(R.id.add_edit_employee).setVisibility(View.VISIBLE);
btnSubmit.setOnClickListener(onNewEmployeeSubmit);
}
};
private View.OnClickListener onShowSearchClicked = new View.OnClickListener() {
@Override
public void onClick(View view) {
findViewById(R.id.lin_add_search).setVisibility(View.GONE);
findViewById(R.id.search_bar).setVisibility(View.VISIBLE);
}
};
private View.OnClickListener onCloseSearchClicked = new View.OnClickListener() {
@Override
public void onClick(View view) {
findViewById(R.id.lin_add_search).setVisibility(View.VISIBLE);
findViewById(R.id.search_bar).setVisibility(View.GONE);
edtSearch.setText("");
refreshList();
}
};
private View.OnClickListener onDoSearchClicked = new View.OnClickListener() {
@Override
public void onClick(View view) {
String input = edtSearch.getText().toString();
if (input.length() == 0) {
Toast.makeText(getActivity(), "لطفا قسمتی از نام کارمند را بنویسید", Toast.LENGTH_SHORT).show();
return;
}
List<Employee> employees = new DatabaseHelper(getActivity()).searchByName(input);
adapter = new MyListAdapter(getActivity(), employees);
listView.setAdapter(adapter);
Toast.makeText(getActivity(), employees.size() + " کارمند پیدا شد", Toast.LENGTH_SHORT).show();
}
};
private View.OnClickListener onCancelbuttonClicked = new View.OnClickListener() {
@Override
public void onClick(View view) {
edtName.setText("");
edtPhone.setText("");
edtAddress.setText("");
findViewById(R.id.lin_add_search).setVisibility(View.VISIBLE);
findViewById(R.id.add_edit_employee).setVisibility(View.GONE);
}
};
private View.OnClickListener onNewEmployeeSubmit = new View.OnClickListener() {
@Override
public void onClick(View view) {
if (edtName.getText().length() == 0 || edtPhone.getText().length() == 0 || edtAddress.getText().length() == 0) {
Toast.makeText(getActivity(), "لطفا اطلاعات را وارد کنید", Toast.LENGTH_SHORT).show();
return;
}
Employee employee = new Employee();
employee.setName(edtName.getText().toString());
employee.setPhone(edtPhone.getText().toString());
employee.setAddress(edtAddress.getText().toString());
new DatabaseHelper(getActivity()).addNewEmployee(employee);
refreshList();
btnCancel.performClick();
}
};
private View.OnClickListener onEditEmployeeSubmit = new View.OnClickListener() {
@Override
public void onClick(View view) {
if (edtName.getText().length() == 0 || edtPhone.getText().length() == 0 || edtAddress.getText().length() == 0) {
Toast.makeText(getActivity(), "لطفا اطلاعات را وارد کنید", Toast.LENGTH_SHORT).show();
return;
}
Employee employee = new Employee();
employee.setId(seletcedEmployeeId);
employee.setName(edtName.getText().toString());
employee.setPhone(edtPhone.getText().toString());
employee.setAddress(edtAddress.getText().toString());
new DatabaseHelper(getActivity()).editEmployee(employee);
refreshList();
btnCancel.performClick();
}
};
}
Android開發人員通常使用兩種名為findViewById()
方法。 其中之一是Activity
類的一部分,通常是這樣調用的:
public void myMethod() {
View myView = findViewById(R.id.myView);
}
另一個是View
類的一部分,通常是這樣調用的:
public void myMethod(View root) {
View myView = root.findViewById(R.id.myView);
}
但是,在Fragment
類中沒有findViewById()
方法,因此必須改用View
方法。 您已經在onCreateView()
做到了:
@Override public View onCreateView(final LayoutInflater inflater, final ViewGroup container, final Bundle savedInstanceState) { final View view = inflater.inflate(R.layout.fragment_customers, null); Button btnAdd = (Button) view.findViewById(R.id.btn_add); ^^^^^^^^^^^^^^^^^
但是,稍后您將看到以下內容:
public void editEmployee(Employee employee) { findViewById(R.id.lin_add_search).setVisibility(View.GONE); ^^^^^^^^^^^^
同樣, Fragment
類沒有findViewById()
方法,因此不會編譯。 通常,解決方法是調用getView().findViewById()
。 getView()
方法返回與從onCreateView()
返回的相同的View
實例,因此它可以正常工作。
像這樣:
public void editEmployee(Employee employee) {
getView().findViewById(R.id.lin_add_search).setVisibility(View.GONE);
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