在哪里添加片段的方法？

Question

我有一个名为fragment的fragment_login.xml和一个名为LoginPageFragment.java的相应类。在我的fragment有2个EditTexts和一个按钮。

我想为我的按钮写一个onClick方法，但我希望它在我的class，以便我可以使用它在哪里我使用我的fragment（动态）。我在我的LoginPageFragment类中编写了该方法的主体，但该程序无法识别它。不确定这里有什么问题？

import android.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;



public class LoginPageFragment extends Fragment {

    private Button btnLogin ;
    private EditText inputUsername , inputPassword ;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        View fragmentView =  inflater.inflate(R.layout.fragment_login, container , false);

        inputUsername = (EditText) fragmentView.findViewById(R.id.input_username);
        inputPassword = (EditText) fragmentView.findViewById(R.id.input_password);
        btnLogin = (Button) fragmentView.findViewById(R.id.btn_login);

        return fragmentView ;
    }

    public void onLoginClick(View v){

        String usernameString = inputUsername.getText().toString() ;
        String passwordString = inputPassword.getText().toString() ;

        if(Utility.areEditTextsEmpty(inputUsername , inputPassword)){
            Toast.makeText(LoginActivity.fa , "Some Fields are EMPTY",Toast.LENGTH_SHORT).show();
        }
        User tempUser =  Utility.doesTheUserExist(usernameString , passwordString);
        if(tempUser != null){

            Utility.sendUserInfoToAnotherActivity(tempUser);

        }
        else{
            Toast.makeText(LoginActivity.fa , "User Not Defined" , Toast.LENGTH_SHORT);
        }
    }
}



<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".LoginActivity"
    android:padding="40dp"
    android:orientation="vertical"
    >


    <EditText
        android:id="@+id/input_username"
        android:inputType="number"
        style="@style/LoginElements"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:drawableRight="@mipmap/username_icon2" />

    <EditText
        android:id="@+id/input_password"
        style="@style/LoginElements"
        android:inputType="textPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:drawableRight="@android:drawable/ic_secure" />

    <Button
        android:id="@+id/btn_login"
        style="@style/LoginElements"
        android:text="@string/loginButtonText"
        android:layout_gravity="center"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="onLoginClick"
        />

</LinearLayout>

Answer 1

xml中的onClick标记需要由活动处理。在片段中，最简单的方法是以编程方式添加单击listerner。另一种方法是让活动处理它然后调用片段上的函数，但这是一个痛苦的问题，如果你改变了片段，可能会有问题。

Answer 2

    enter code here


public class LoginPageFragment extends Fragment {

    private Button btnLogin ;
    private EditText inputUsername , inputPassword ;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        View fragmentView =  inflater.inflate(R.layout.fragment_login, container , false);

        inputUsername = (EditText) fragmentView.findViewById(R.id.input_username);
        inputPassword = (EditText) fragmentView.findViewById(R.id.input_password);
        btnLogin = (Button) fragmentView.findViewById(R.id.btn_login);


        btnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String usernameString = inputUsername.getText().toString() ;
                String passwordString = inputPassword.getText().toString() ;

                if(Utility.areEditTextsEmpty(inputUsername , inputPassword)){
                    Toast.makeText(LoginActivity.fa , "Some Fields are EMPTY",Toast.LENGTH_SHORT).show();
                }
                User tempUser =  Utility.doesTheUserExist(usernameString , passwordString);
                if(tempUser != null){

                    Utility.sendUserInfoToAnotherActivity(tempUser);

                }
                else{
                    Toast.makeText(LoginActivity.fa , "User Not Defined" , Toast.LENGTH_SHORT);
                }

            }
        });

        return fragmentView ;
    }

    public void onLoginClick(View v){

        String usernameString = inputUsername.getText().toString() ;
        String passwordString = inputPassword.getText().toString() ;

        if(Utility.areEditTextsEmpty(inputUsername , inputPassword)){
            Toast.makeText(LoginActivity.fa , "Some Fields are EMPTY",Toast.LENGTH_SHORT).show();
        }
        User tempUser =  Utility.doesTheUserExist(usernameString , passwordString);
        if(tempUser != null){

            Utility.sendUserInfoToAnotherActivity(tempUser);

        }
        else{
            Toast.makeText(LoginActivity.fa , "User Not Defined" , Toast.LENGTH_SHORT);
        } 
    } 
}