Fragment学习

利用Fragment可以动态的加载页面，减少Activity的数量。

便于开发

类似与html中FragmentSet一样

嵌套在一起，使每个页面为独立的

代码如下：

package com.example.chaoba.study;

import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
private Dongtai dongtai;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button butn1=findViewById(R.id.butn1);
        butn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                FragmentManager fragmentManager = getFragmentManager(); //加载一个Fragment需要先创建管理器，
                FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();  //获取FragmentTransaction对象
                if (dongtai==null){
                    dongtai=new Dongtai();

                }

                fragmentTransaction.replace(R.id.content,dongtai);  //移除所有，然后添加    或者    add方法
                fragmentTransaction.commit();//提交
            }
        });

    }
}

package com.example.chaoba.study;

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.TextView;

/**
 * Created by chaoba on 18-5-31.
 */

public class Dongtai extends Fragment implements View.OnClickListener{
       TextView tv;
    View view;
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
         view=inflater.inflate(R.layout.dongtai,container,false);  //创建view

        return view;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
//重写本方法，用于编写业务逻辑。
        initView();
        tv.setText("11111111111111");
        tv.setOnClickListener(this);  //测试点击事件，效果  11111变成5555

    }

    public void initView(){

         tv = view.findViewById(R.id.textView2);
    }

    public void test(){
        tv.setText("5555555");

    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.textView2:test();break;

        }
    }
}