Android(X)多页面

1. 添加setContentView(R.layout.activity_main);

1. 在安卓中每个页面我们称为一个Activity，Activity之间使用Intent进行通信

2. 打开页面

   Intent intent = new Intent(NewAvtivity.this,ThirdPage.class);
    startActivity(intent);
   

3. 关闭页面

     finish(); //关闭当前Activity
   

1. 页面间使用Bundle进行通信，所有的数据都传输到Bundle里面

2. 发送方（按键监听函数）

    button.setOnClickListener(new View.OnClickListener() {
               @Override
               public void onClick(View v) {
                   String input_text = ((EditText)findViewById(R.id.input_sth)).getText().toString();
                   Bundle bundle = new Bundle();
                   bundle.putCharSequence("input",input_text); //将信息放入Bundle
                   Intent intent = new Intent(MainActivity.this,NewAvtivity.class);
                   intent.putExtras(bundle);//将bundle放到intent里面
                   startActivity(intent);//开启另一个页面
               }
           });
   

3. 接受方（文本框）

           Intent intent = getIntent(); //实例化Intent
           Bundle bundle = intent.getExtras();//实例化Bundle，获取消息
           TextView textView = (TextView)findViewById(R.id.new_page_text);
           textView.setText(bundle.getString("input"));//将消息放入文本框中
   

1. 发送方

   but1.setOnClickListener(new View.OnClickListener() {
               @Override
               public void onClick(View v) {
                   Intent intent = getIntent();
                   Bundle bundle = new Bundle();
                   bundle.putString("username",username.getText().toString());
                   bundle.putString("passwd",passwd.getText().toString());
   
                   intent.putExtras(bundle);
                   setResult(0x11,intent);
                   finish();
               }
           });
   

2. 接收方

   public class MainActivity extends Activity {
       @Override
       protected void onCreate(@Nullable Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.activity_main);
           Button openbut = (Button)findViewById(R.id.open_new);
           openbut.setOnClickListener(new View.OnClickListener() {
               @Override
               public void onClick(View v) {
                   Intent intent = new Intent(MainActivity.this,NewAvtivity.class);
                   startActivityForResult(intent,0x11);
   
               }
           });
   
       }
   
       @Override
       protected void onActivityResult(int requestCode, int resultCode, Intent data) {
           super.onActivityResult(requestCode, resultCode, data);
           if(requestCode==0x11&&resultCode==0x11){
               Bundle bundle = data.getExtras();
               String str1 = bundle.getString("username");
               String str2 = bundle.getString("passwd");
               TextView un = (TextView) findViewById(R.id.username);
               TextView ps = (TextView) findViewById(R.id.passwd);
               un.setText(str1);
               ps.setText(str2);
   
   
           }
       }
   }
   

View.OnClickListener l = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            
        }
    }

1. 两个帧java文件：新建类继承Frame，重写 onCreateView方法，写两个这样的类

package com.example.activity;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

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

public class me_fragment extends Fragment {
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view  =inflater.inflate(R.layout.me_fragment,null);
        return view;
    }
}

2. 主java文件

package com.example.activity;

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

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

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

        ImageView imageView1 = findViewById(R.id.img1);//获取控件
        ImageView imageView2 = findViewById(R.id.img2);//获取控件

        imageView1.setOnClickListener(l);//设置监听器
        imageView2.setOnClickListener(l);//设置监听器


    }
    View.OnClickListener l = new View.OnClickListener() {//监听器
        @Override
        public void onClick(View v) {
            FragmentManager fm = getSupportFragmentManager();//帧管理器
            FragmentTransaction ft = fm.beginTransaction();
            Fragment f=null;//实例化帧对象指向空

            switch (v.getId()){
                case R.id.img1://如果第一个方块被点击
                    f= new wechat_fragment();//导入新的帧
                    break;
                case R.id.img2://如果第二个方块被点击
                    f= new me_fragment();//导入新的帧
                    break;

            }
            ft.replace(R.id.fragment,f);//替换
            ft.commit();//提交
      }
    };
}

3. 两个帧xml文件

4. 主xml文件（开始的帧布局采用的是其中一个帧xml）