package com.jay.myappstudy;

import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

import com.jay.common.LocalDateTimeUtil;

public class FragmentTest1 extends Fragment {
    /**
     * 畫面視圖
     */
    private View mView;
    /**
     * 刷新按鈕
     */
    private Button btnRefresh;
    /**
     * 展示文本
     */
    private TextView txtMsg;
    /**
     * 參數(shù)1
     */
    private String mPara1;
    /**
     * Fragment回調(diào)函數(shù)
     */
    private Callbacks mCallbacks;
    /**
     * 按鈕事件
     */
    private View.OnClickListener clickListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            switch (v.getId()) {
                case R.id.btnRefresh:
                    String nowStr = LocalDateTimeUtil.getNowString();
                    txtMsg.setText("當(dāng)前時(shí)間:" + nowStr);
                    executeCallback(nowStr);
                    break;
                default:
                    txtMsg.setText("未知操作");
                    break;
            }
        }
    };

    public FragmentTest1() {
    }

    /**
     * 構(gòu)造函數(shù)傳參
     */
    public FragmentTest1(String para1) {
        this.mPara1 = para1;
    }

    public FragmentTest1(String para1, Callbacks callback) {
        this.mPara1 = para1;
        this.mCallbacks = callback;
    }

    /**
     * Fragment繪制界面組件時(shí)回調(diào)該方法，必須返回一個(gè)View，該View即為Fragment所顯示的View。
     */
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        //return super.onCreateView(inflater, container, savedInstanceState);
        mView = inflater.inflate(R.layout.fragment_test_form1, container, false);
        //獲取和設(shè)置視圖中的控件
        if (mView != null) {
            btnRefresh = mView.findViewById(R.id.btnRefresh);
            txtMsg = mView.findViewById(R.id.txtMsg);
            btnRefresh.setOnClickListener(clickListener);
        }
        return mView;
    }

    /**
     * 創(chuàng)建Fragment時(shí)回調(diào)。只會(huì)被調(diào)用一次。
     * 系統(tǒng)創(chuàng)建Fragment對(duì)象后回調(diào)該方法，用于初始化想要在Fragment中保持的必要組件。
     */
    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //獲取啟動(dòng)Fragment時(shí)的參數(shù)
        String paraName = "para1";
        Bundle bundle = getArguments();
        if (bundle != null && bundle.containsKey(paraName)) {
            //獲取Bundle中保存的參數(shù)，用來做后續(xù)操作，比如查詢數(shù)據(jù)庫。
            String para1Value = bundle.getString(paraName);
            Log.i("FragmentTest", "獲取參數(shù)：" + para1Value);
        }
    }

    /**
     * 當(dāng)Fragment被添加到其所在的Context時(shí)回調(diào)。只會(huì)被調(diào)用一次。
     * onAttach()方法的參數(shù)是一個(gè)Context對(duì)象，表示宿主Activity的上下文。
     * 通過該參數(shù)，F(xiàn)ragment可以獲取到宿主Activity的引用，從而與宿主Activity進(jìn)行通信和交互。
     */
    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        //Fragment所在Activity集成實(shí)現(xiàn)回調(diào)接口函數(shù)，可以通過以下方式得到回調(diào)函數(shù)對(duì)象。
//        if (!(context instanceof Callbacks)) {
//            throw new IllegalStateException("Fragment所在的Activity必須實(shí)現(xiàn)Callbacks接口!");
//        }
//        mCallbacks = (Callbacks) context;
    }

    /**
     * 執(zhí)行回調(diào)函數(shù)前可以執(zhí)行Fragment本身相關(guān)邏輯。
     * */
    public void executeCallback(String para) {
        //回調(diào)之前的處理邏輯...
        //回調(diào)接口
        if (this.mCallbacks != null) {
            this.mCallbacks.onFragmentCallback(para);
        }
    }

    /**
     * 回調(diào)接口定義
     */
    public interface Callbacks {
        void onFragmentCallback(String para);
    }
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:id="@+id/txtMsg"
        android:layout_width="match_parent"
        android:layout_height="20dp"
        android:text="點(diǎn)擊按鈕獲取當(dāng)前時(shí)間..."></TextView>

    <Button
        android:id="@+id/btnRefresh"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:text="當(dāng)前時(shí)間"></Button>
</LinearLayout>

FragmentTest1 test1 = new FragmentTest1("abc", new FragmentTest1.Callbacks() {
    @Override
    public void onFragmentCallback(String para) {
        Log.i("IncludeFormActivity","從Fragment中接收到的回調(diào)參數(shù)：" + para);
    }
});
//創(chuàng)建Fragment時(shí)傳參
Bundle paras = new Bundle();
paras.putString("para1","來自Activity的參數(shù)。");
test1.setArguments(paras);
//加載Fragment
openForm(test1);

    /**
     * 刪除當(dāng)前Activity中的所有Fragment
     * */
    private void closeAllForm(){
        FragmentManager fm = ctx.getSupportFragmentManager();
        FragmentTransaction ft = fm.beginTransaction();
        //刪除所有Fragment
        List<Fragment> fragments = fm.getFragments();
        if (fragments != null) {
            for (Fragment fra : fragments) {
                ft.remove(fra);
            }
        }
        ft.commit();
        fm.executePendingTransactions();
        fragments.clear();
        fm.getFragments().clear();
        fragments = fm.getFragments();
        if (fragments != null) {
            for (int i = 0; i < fragments.size(); i++) {
                ft.hide(fragments.get(i));
            }
        }
    }

    /**
     * 加載Fragment到當(dāng)前Activity中
     * */
    private void openForm(Fragment fragment){
        FragmentActivity act = (FragmentActivity) ctx;
        FragmentManager fm = ctx.getSupportFragmentManager();
        FragmentTransaction ft = fm.beginTransaction();
        ft.remove(fragment);
        //刪除所有Fragment
        closeAllForm();
        List<Fragment> fragments = fm.getFragments();
        if (fragments != null) {
            for (int i = 0; i < fragments.size(); i++) {
                ft.hide(fragments.get(i));
            }
        }
        //Add Fragment 到容器中，可以是RelativeLayout或FrameLayout等容器。
        ft.add(R.id.mainContentArea, fragment);
        ft.show(fragment);
        ft.commit();
        fm.executePendingTransactions();
    }

            <!-- 方式1:直接引入一個(gè)Fragment -->
            <fragment
                android:id="@+id/fmTest1"
                android:name="com.jay.myappstudy.FragmentTest1"
                android:layout_width="match_parent"
                android:layout_height="100dp"
                />
            <!-- 方式2:添加一個(gè)Layout容器，使用后臺(tái)代碼加載Fragment到這個(gè)容器中 -->
            <FrameLayout
                android:id="@+id/mainContentArea"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />