Android实现闹钟设置并全局广播的代码和布局

以下是一个简单的Android闹钟设置和全局广播的代码示例，包括布局文件和Java代码：

布局文件：activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<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/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Set Alarm" />

    <TimePicker
        android:id="@+id/timePicker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Set Alarm" />

</LinearLayout>

Java代码：MainActivity.java

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.TimePicker;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import java.util.Calendar;

public class MainActivity extends AppCompatActivity {

    AlarmManager alarmManager;
    TimePicker timePicker;
    TextView updateText;
    Context context;
    PendingIntent pendingIntent;

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

        alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
        timePicker = (TimePicker) findViewById(R.id.timePicker);
        updateText = (TextView) findViewById(R.id.textView);

        final Calendar calendar = Calendar.getInstance();

        Button start_alarm = (Button) findViewById(R.id.button);
        start_alarm.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                calendar.set(Calendar.HOUR_OF_DAY, timePicker.getCurrentHour());
                calendar.set(Calendar.MINUTE, timePicker.getCurrentMinute());

                int hour = timePicker.getCurrentHour();
                int minute = timePicker.getCurrentMinute();

                String hour_string = String.valueOf(hour);
                String minute_string = String.valueOf(minute);

                if (hour > 12) {
                    hour_string = String.valueOf(hour - 12);
                }

                if (minute < 10) {
                    minute_string = "0" + String.valueOf(minute);
                }

                setAlarmText("Alarm set to: " + hour_string + ":" + minute_string);

                Intent intent = new Intent(context, AlarmReceiver.class);
                pendingIntent = PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);

                alarmManager.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);
            }
        });
    }

    public void setAlarmText(String alarmText) {
        updateText.setText(alarmText);
    }

    public static class AlarmReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            Toast.makeText(context, "Wake up!", Toast.LENGTH_LONG).show();
        }
    }
}

在此示例中，我们使用了一个 `TimePicker` 控件让用户选择时间，然后使用 `AlarmManager` 在指定时间触发一个广播。我们也创建了一个广播接收器 `AlarmReceiver`，以便在指定时间触发时显示一个 `Toast` 消息。

请注意，这只是一个简单的示例，并且可能需要进行更多的修改和改进才能符合您的实际需求。