Andorid第一次作业

请根据课程实操实现APP门户界面框架设计，至少包含4个tab页，能实现tab页之间的点击切换；
2、技术：使用布局（layouts）和分段（fragment），对控件进行点击监听；

创建视图并通过id联系控件，设置监听，定义四个Fragment并将其压入控件内，对四个linerLayout的点击监听进行重写，以及点击切换fragment和图标。

fragment控件的使用，多个fragment的创建和压入控件，点击监听的设置

1.打开界面

2.点击效果

```java
package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;

import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.ImageView;
import android.widget.LinearLayout;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private Fragment wechatFragment = new WechatFragment();
    private Fragment friendFragment = new FriendFragment();
    private Fragment contectFragment = new ContectFragment();
    private Fragment configFragment = new ConfigFragment();

    private FragmentManager fragmentManager;

    private LinearLayout linearLayout1;
    private LinearLayout linearLayout2;
    private LinearLayout linearLayout3;
    private LinearLayout linearLayout4;

    private ImageView view1;
    private ImageView view2;
    private ImageView view3;
    private ImageView view4;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);

        linearLayout1 = findViewById(R.id.linearLayout1);
        linearLayout2 = findViewById(R.id.linearLayout2);
        linearLayout3 = findViewById(R.id.linearLayout3);
        linearLayout4 = findViewById(R.id.linearLayout4);

        view1 = findViewById(R.id.imageView1);
        view2 = findViewById(R.id.imageView2);
        view3 = findViewById(R.id.imageView3);
        view4 = findViewById(R.id.imageView4);

        linearLayout1.setonClickListener(this);
        linearLayout2.setonClickListener(this);
        linearLayout3.setonClickListener(this);
        linearLayout4.setonClickListener(this);

        initFragment();
    }

    protected void initFragment(){
        fragmentManager = getSupportFragmentManager();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.add(R.id.content,wechatFragment);
        transaction.add(R.id.content,friendFragment);
        transaction.add(R.id.content,contectFragment);
        transaction.add(R.id.content,configFragment);
        hideFragment(transaction);
        transaction.show(wechatFragment);
        transaction.commit();
    }

    protected void hideFragment(FragmentTransaction transaction){
        transaction.hide(wechatFragment);
        transaction.hide(friendFragment);
        transaction.hide(contectFragment);
        transaction.hide(configFragment);
    }

    @Override
    public void onClick(View v){
        switch (v.getId()){
            case R.id.linearLayout1:
                showFragment(1);
                break;
            case R.id.linearLayout2:
                showFragment(2);
                break;
            case R.id.linearLayout3:
                showFragment(3);
                break;
            case R.id.linearLayout4:
                showFragment(4);
                break;
            default:
                break;
        }
    }

    protected void showFragment(int i){
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        hideFragment(transaction);
        switch (i) {
            case 1:
                setEmpty();
                view1.setImageResource(R.drawable.wechat1);
                transaction.show(wechatFragment);
                break;
            case 2:
                setEmpty();
                view2.setImageResource(R.drawable.friend1);
                transaction.show(friendFragment);
                break;
            case 3:
                setEmpty();
                view3.setImageResource(R.drawable.config1);
                transaction.show(contectFragment);
                break;
            case 4:
                setEmpty();
                view4.setImageResource(R.drawable.contect1);
                transaction.show(configFragment);
                break;
            default:
                break;
        }
        transaction.commit();
    }

    protected void setEmpty(){
        view1.setImageResource(R.drawable.wechat);
        view2.setImageResource(R.drawable.friend);
        view3.setImageResource(R.drawable.config);
        view4.setImageResource(R.drawable.contect);
    }

}

通过这次作业，我了解了简单的控件布局，并掌握了一些控件的控制方法，setOnClickListener绑定控件以及简单应用。对安卓的调度机制有了一定的认识。

作业源码地址