编程实现 Android 手机上 WiFi 操作，要求有java文件和xml布局文件

以下是一个简单的 Android WiFi 操作的示例，包括一个Java文件和一个XML布局文件。

1. Java文件

import android.content.Context;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import java.util.List;

public class MainActivity extends AppCompatActivity {
    private WifiManager wifiManager;
    private EditText wifiNameEditText, wifiPasswordEditText;
    private TextView wifiStatusTextView, wifiInfoTextView;

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

        wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);

        wifiNameEditText = findViewById(R.id.wifiNameEditText);
        wifiPasswordEditText = findViewById(R.id.wifiPasswordEditText);
        wifiStatusTextView = findViewById(R.id.wifiStatusTextView);
        wifiInfoTextView = findViewById(R.id.wifiInfoTextView);

        Button connectButton = findViewById(R.id.connectButton);
        connectButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String wifiName = wifiNameEditText.getText().toString();
                String wifiPassword = wifiPasswordEditText.getText().toString();

                connectToWifi(wifiName, wifiPassword);
            }
        });

        Button disconnectButton = findViewById(R.id.disconnectButton);
        disconnectButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                disconnectFromWifi();
            }
        });

        Button wifiInfoButton = findViewById(R.id.wifiInfoButton);
        wifiInfoButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                showWifiInfo();
            }
        });
    }

    private void connectToWifi(String wifiName, String wifiPassword) {
        WifiConfiguration wifiConfig = new WifiConfiguration();
        wifiConfig.SSID = String.format("\"%s\"", wifiName);
        wifiConfig.preSharedKey = String.format("\"%s\"", wifiPassword);

        int netId = wifiManager.addNetwork(wifiConfig);
        wifiManager.disconnect();
        wifiManager.enableNetwork(netId, true);
        wifiManager.reconnect();

        wifiStatusTextView.setText("Connecting...");
    }

    private void disconnectFromWifi() {
        wifiManager.disconnect();
        wifiStatusTextView.setText("Disconnected");
    }

    private void showWifiInfo() {
        WifiInfo wifiInfo = wifiManager.getConnectionInfo();
        wifiInfoTextView.setText("SSID: " + wifiInfo.getSSID() + "\n" +
                "BSSID: " + wifiInfo.getBSSID() + "\n" +
                "Speed: " + wifiInfo.getLinkSpeed() + WifiInfo.LINK_SPEED_UNITS + "\n" +
                "Signal Strength: " + wifiInfo.getRssi() + " dBm" + "\n" +
                "IP Address: " + intToIp(wifiInfo.getIpAddress()));
    }

    private String intToIp(int i) {
        return ((i >> 24) & 0xFF) + "." +
                ((i >> 16) & 0xFF) + "." +
                ((i >> 8) & 0xFF) + "." +
                (i & 0xFF);
    }
}

2. XML布局文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:padding="16dp"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/wifiNameEditText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="WiFi Name"
        android:inputType="text" />

    <EditText
        android:id="@+id/wifiPasswordEditText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/wifiNameEditText"
        android:hint="WiFi Password"
        android:inputType="textPassword" />

    <Button
        android:id="@+id/connectButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/wifiPasswordEditText"
        android:layout_marginTop="16dp"
        android:text="Connect" />

    <Button
        android:id="@+id/disconnectButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/connectButton"
        android:layout_marginTop="16dp"
        android:text="Disconnect" />

    <Button
        android:id="@+id/wifiInfoButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/disconnectButton"
        android:layout_marginTop="16dp"
        android:text="WiFi Info" />

    <TextView
        android:id="@+id/wifiStatusTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/wifiInfoButton"
        android:layout_marginTop="16dp"
        android:textAlignment="center"
        android:textSize="18sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/wifiInfoTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/wifiStatusTextView"
        android:layout_marginTop="16dp"
        android:textSize="18sp" />

</RelativeLayout>