Android 火车票APP之登录以及Fragment导航切换（3）

登录和注册的xml都是差不多，我就不写了，我现在没用数据库，用文件储存用户信息。
loginActivity

public class LoginActivity extends AppCompatActivity {
    private EditText phone, password;
    private Button login;
    private SharedPreferences preferences;
    private SharedPreferences.Editor editor;

    @Override
    protected void onCreate( Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        phone = (EditText) findViewById(R.id.phone_input);
        password = (EditText) findViewById(R.id.password_input);
        login = (Button) findViewById(R.id.btn_login);
        preferences = getSharedPreferences("UserInfo", MODE_PRIVATE);
        editor = preferences.edit();

        final String name = preferences.getString("userPhone",null);
        if (name != null) {
            phone.setText(name);
        }
        final String passwords = preferences.getString("userPassword", null);
        if (passwords != null) {
            password.setText(passwords);
        }

        login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(getFile(phone.getText().toString(),password.getText().toString())){
                    editor.putInt("isLogin",1);
                    editor.apply();
                    Intent intent = new Intent(LoginActivity.this,MustActivity.class);
                    startActivity(intent);
                    LoginActivity.this.finish();
                }else{
                    Toast.makeText(getApplicationContext(),"手机号或密码错误",Toast.LENGTH_SHORT).show();
                }


            }
        });
    }

    private boolean getFile(String name,String password){
        BufferedReader reader = null;
        StringBuilder sb = new StringBuilder("");
        boolean isRight = false;
        try {
            String sdCardDir = Environment.getExternalStorageDirectory().getAbsolutePath();//获取SDCard目录
            File dir = new File(sdCardDir + "/" + getPackageName());
            FileInputStream input = new FileInputStream(dir+"/userInfo.txt");
            reader=new BufferedReader(new InputStreamReader(input));
            String line = "";

            while ((line=reader.readLine())!=null) {
                String [] result = line.split("@");
                if(result[0].equals(name) &&result[1].equals(password)){
                    isRight = true;
                }else{
                    isRight =  false;
                }


            }
            reader.close();
            } catch (FileNotFoundException e1) {
            e1.printStackTrace();
        } catch (IOException e1) {
            e1.printStackTrace();
        }

             return isRight;
        }


}

底部我做了个导航栏，上面利用Fragment和下面的点击监听相对，就能完成导航功能了。
xml：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
                                             xmlns:app="http://schemas.android.com/apk/res-auto"
                                             xmlns:tools="http://schemas.android.com/tools"
                                             android:id="@+id/main"
                                             android:background="@drawable/whtrain"
                                             android:layout_width="match_parent"
                                             android:layout_height="match_parent">

    <LinearLayout android:layout_width="match_parent"
                  android:layout_height="0dp"
                  app:layout_constraintVertical_weight="1"
                  android:id="@+id/content"
                  android:orientation="vertical"
                  app:layout_constraintBottom_toTopOf="@+id/linearLayout"
                  app:layout_constraintStart_toStartOf="parent"
                  app:layout_constraintEnd_toEndOf="parent"
                  app:layout_constraintTop_toTopOf="parent"
                  app:layout_constraintVertical_bias="0.49"
                  />

    <LinearLayout
            android:layout_alignParentBottom="true"
            android:orientation="horizontal"
            android:layout_width="match_parent"
            android:layout_height="75dp"
            android:background="#daffffff"
            app:layout_constraintBottom_toBottomOf="parent"
            android:layout_marginBottom="48dp" app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.52"
            android:id="@+id/linearLayout">
        <LinearLayout
                android:orientation="vertical"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:layout_gravity="center"
                android:gravity="center"
        >
            <ImageView
                    android:id="@+id/item1"

                    android:layout_marginTop="10dp"
                    android:layout_width="100dp"
                    android:layout_height="40dp"
                    android:src="@drawable/filesearch"/>

            <TextView android:layout_width="100dp"
                      android:layout_height="20dp"
                      android:gravity="center"
                      android:text="订票"

            />

        </LinearLayout>
        <LinearLayout
                android:orientation="vertical"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:layout_gravity="center"
                android:gravity="center"
        >
            <ImageView
                    android:id="@+id/item2"

                    android:layout_marginTop="10dp"
                    android:layout_width="100dp"
                    android:layout_height="40dp"
                    android:src="@drawable/user"/>

            <TextView android:layout_width="100dp"
                      android:layout_height="20dp"
                      android:gravity="center"
                      android:text="我的"

            />

        </LinearLayout>
    </LinearLayout>



</android.support.constraint.ConstraintLayout>

下面是Activity代码：

package com.dianmo.flash;

public class MustActivity extends AppCompatActivity implements View.OnClickListener {

    private ImageView item1,item2;
    private FragmentManager fragmentManager;
    private ImageView[] ivs;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_must);
        fragmentManager = getSupportFragmentManager();
        item1 = (ImageView) findViewById(R.id.item1);
        item1.setOnClickListener(this);
        item2 = (ImageView) findViewById(R.id.item2);
        item2.setOnClickListener(this);
        ivs = new ImageView[]{item1,item2};
        android.support.v4.app.FragmentTransaction transaction = fragmentManager.beginTransaction();//创建一个事务
        transaction.replace(R.id.content, new FragmentA());
        transaction.commit();//事务一定要提交，replace才会有效
        setCheck(0);

    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.item1: {
                android.support.v4.app.FragmentTransaction transaction = fragmentManager.beginTransaction();//创建一个事务
                transaction.replace(R.id.content, new FragmentA());
                transaction.commit();//事务一定要提交，replace才会有效
                setCheck(0);//自定义方法
                break;
            }
            case R.id.item2: {
                android.support.v4.app.FragmentTransaction transaction = fragmentManager.beginTransaction();//创建一个事务
                transaction.replace(R.id.content, new FragmentB());
                transaction.commit();//事务一定要提交，replace才会有效
                setCheck(1);//自定义方法
                break;
            }
            default:break;
        }
    }

    public void setCheck(int itemId){
               //这个方法设置底部导航栏选中时的效果
             for (int i = 0; i < 2; i++) {
                      ivs[i].setColorFilter(Color.BLACK);
                  //     tvs[i].setTextColor(Color.parseColor("#0f0f0f"));
                   }
                 ivs[itemId].setColorFilter(Color.parseColor("#FFD9682F"));
             //  tvs[itemId].setTextColor(Color.GREEN);
           }



}

注意类一定要implements View.OnClickListener

下面我们来设计Fragment
在Fragment中，我们要把代码写到OnActivityCreated中，而且大部分的方法都要靠getActivity()来获取。

<FrameLayout 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"
             tools:context="com.dianmo.flash.Fragment.FragmentA">

    <!-- TODO: Update blank fragment layout -->
    <LinearLayout android:layout_width="match_parent"
                  android:orientation="vertical"
                  android:layout_height="match_parent">

    <LinearLayout android:layout_width="match_parent"
                  android:layout_marginTop="24dp"
                  android:layout_height="60dp"
                  android:gravity="center"
                  android:background="#dffc8c1b"
    >
        <TextView android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:textColor="#ffffff"
                  android:textSize="28dp"
                  android:text="火车票查询"/>
    </LinearLayout>
    <LinearLayout
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:background="#52ffffff"
            >
        <LinearLayout android:layout_width="match_parent"
                      android:layout_height="0dp"
                      android:layout_weight="1"
        />
        <LinearLayout android:layout_width="match_parent"
                      android:layout_height="0dp"
                      android:layout_weight="1"
                      android:gravity="center_vertical"
                      android:orientation="horizontal">
            <LinearLayout android:layout_width="0dp"
                          android:layout_height="match_parent"
                          android:layout_weight="2"
                          android:orientation="vertical"
                          android:gravity="center"
                          android:layout_gravity="center">
                <TextView
                        android:text="出发地"
                        android:layout_width="130dp"
                        android:layout_height="50dp"
                        android:id="@+id/start_input"
                        android:textSize="36sp"
                        android:textStyle="bold"
                        android:textAlignment="center"
                        android:layout_marginTop="30dp"
                />
            </LinearLayout>
            <LinearLayout android:layout_width="0dp"
                          android:layout_height="match_parent"
                          android:layout_weight="1"
                          android:gravity="center"
                          android:layout_gravity="center"
                          android:orientation="vertical">
                <ImageView android:layout_width="50dp"
                           android:layout_height="50dp"
                           android:layout_marginTop="26dp"
                           android:src="@drawable/swap"
                           android:id="@+id/turn"
                />
            </LinearLayout>

            <LinearLayout android:layout_width="0dp"
                          android:layout_height="match_parent"
                          android:layout_weight="2"
                          android:orientation="vertical"
                          android:gravity="center"
                          android:layout_gravity="center">
                <TextView
                        android:text="目的地"
                        android:layout_width="120dp"
                        android:layout_height="50dp"
                        android:id="@+id/end_input"
                        android:textStyle="bold"
                        android:textAlignment="center"
                        android:textSize="36sp"
                        android:layout_marginTop="30dp"
                />
            </LinearLayout>


        </LinearLayout>
        <LinearLayout
                      android:layout_marginTop="20dp"
                      android:layout_width="match_parent"
                      android:layout_height="0dp"
                      android:layout_weight="1"
        />

        <LinearLayout android:layout_width="match_parent"
                      android:layout_height="0dp"
                      android:layout_weight="5"
                      android:gravity="center"
                      android:layout_gravity="center"
        >
            <Button
                    android:background="@drawable/shape"
                    android:text="查询"
                    android:textColor="#ffffff"
                    android:textSize="26dp"
                    android:layout_width="300dp"
                    android:layout_height="50dp"
                    android:id="@+id/check_btn"



            />

        </LinearLayout>




    </LinearLayout>
    </LinearLayout>



</FrameLayout>

Activity代码：

package com.dianmo.flash.Fragment;


import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.annotation.Nullable;
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.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import com.dianmo.flash.R;
import com.dianmo.flash.SelectActivity;
import com.dianmo.flash.ShowActivity;

import static android.content.Context.MODE_PRIVATE;

/**
 * A simple {@link Fragment} subclass.
 */
public class FragmentA extends Fragment {
    private Button check;
    private SharedPreferences sp;
    private SharedPreferences.Editor editor;
    private Bundle bd = new Bundle();
    private TextView start , end;
    private ImageView turn;
    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        sp = this.getActivity().getSharedPreferences("cityInfo",MODE_PRIVATE);
        editor =sp.edit();
        start = (TextView) getActivity().findViewById(R.id.start_input);
        turn = (ImageView) getActivity().findViewById(R.id.turn);
        end = (TextView) getActivity().findViewById(R.id.end_input);
        check = (Button) getActivity().findViewById(R.id.check_btn);

        start.setText(sp.getString("start","出发地"));
        end.setText(sp.getString("end","目的地"));
        start.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(getActivity(),SelectActivity.class);
                bd.putInt("key",100);
                intent.putExtras(bd);
                startActivity(intent);
                getActivity().finish();
            }
        });

        turn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                String s1 = start.getText().toString();
                String s2 = end.getText().toString();
                editor.putString("start",s2);
                editor.putString("end",s1);
                editor.apply();
                start.setText(s2);
                end.setText(s1);
            }
        });

        end.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(getActivity(),SelectActivity.class);
                bd.putInt("key",101);
                intent.putExtras(bd);
                startActivity(intent);
                getActivity().finish();
            }
        });

        check.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String s1 = start.getText().toString();
                String s2 = end.getText().toString();
                if(s1.equals(s2)){
                    Toast.makeText(getActivity(),"出发地和目的地不得相同",Toast.LENGTH_SHORT).show();
                }else{
                    Intent intent = new Intent(getActivity(),ShowActivity.class);
                    bd.putString("start",s1);
                    bd.putString("end",s2);
                    intent.putExtras(bd);
                    startActivity(intent);
                    getActivity().finish();
                }

            }
        });
    }


    public FragmentA() {
        // Required empty public constructor


    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_blank, container, false);
    }

}

按照这样的格式写几个Fragment，再到activity中加入switch case语句即可。