Question

我需要在Windows系统中获得剩余电量。我该怎么办？

Answer 1

我假设你在谈论一台笔记本电脑。 Standard Java SE API中不存在此类API。此信息仅在操作系统平台本机API中提供。您至少需要JNI或JNA (JavaWorld article)才能与平台本机API进行通信。

在Windows中，您想要挂钩SYSTEM_POWER_STATUS structure。它提供了您可能感兴趣的BatteryLifePercent财产。我在旧的forums.sun.com主题中找到了一个有用的基于JNA的代码片段，目前暂不可用。因此，信用实际上归于名称不可知的作者。

要使其工作，首先将jna.jar放在类路径中，然后将未修改的以下类复制到项目中：

package com.example;

import java.util.ArrayList;
import java.util.List;

import com.sun.jna.Native;
import com.sun.jna.Structure;
import com.sun.jna.win32.StdCallLibrary;

public interface Kernel32 extends StdCallLibrary {

    public Kernel32 INSTANCE = (Kernel32) Native.loadLibrary("Kernel32", Kernel32.class);

    /**
     * @see http://msdn2.microsoft.com/en-us/library/aa373232.aspx
     */
    public class SYSTEM_POWER_STATUS extends Structure {
        public byte ACLineStatus;
        public byte BatteryFlag;
        public byte BatteryLifePercent;
        public byte Reserved1;
        public int BatteryLifeTime;
        public int BatteryFullLifeTime;

        @Override
        protected List<String> getFieldOrder() {
            ArrayList<String> fields = new ArrayList<String>();
            fields.add("ACLineStatus");
            fields.add("BatteryFlag");
            fields.add("BatteryLifePercent");
            fields.add("Reserved1");
            fields.add("BatteryLifeTime");
            fields.add("BatteryFullLifeTime");
            return fields;
        }

        /**
         * The AC power status
         */
        public String getACLineStatusString() {
            switch (ACLineStatus) {
                case (0): return "Offline";
                case (1): return "Online";
                default: return "Unknown";
            }
        }

        /**
         * The battery charge status
         */
        public String getBatteryFlagString() {
            switch (BatteryFlag) {
                case (1): return "High, more than 66 percent";
                case (2): return "Low, less than 33 percent";
                case (4): return "Critical, less than five percent";
                case (8): return "Charging";
                case ((byte) 128): return "No system battery";
                default: return "Unknown";
            }
        }

        /**
         * The percentage of full battery charge remaining
         */
        public String getBatteryLifePercent() {
            return (BatteryLifePercent == (byte) 255) ? "Unknown" : BatteryLifePercent + "%";
        }

        /**
         * The number of seconds of battery life remaining
         */
        public String getBatteryLifeTime() {
            return (BatteryLifeTime == -1) ? "Unknown" : BatteryLifeTime + " seconds";
        }

        /**
         * The number of seconds of battery life when at full charge
         */
        public String getBatteryFullLifeTime() {
            return (BatteryFullLifeTime == -1) ? "Unknown" : BatteryFullLifeTime + " seconds";
        }

        @Override
        public String toString() {
            StringBuilder sb = new StringBuilder();
            sb.append("ACLineStatus: " + getACLineStatusString() + "\n");
            sb.append("Battery Flag: " + getBatteryFlagString() + "\n");
            sb.append("Battery Life: " + getBatteryLifePercent() + "\n");
            sb.append("Battery Left: " + getBatteryLifeTime() + "\n");
            sb.append("Battery Full: " + getBatteryFullLifeTime() + "\n");
            return sb.toString();
        }
    }

    /**
     * Fill the structure.
     */
    public int GetSystemPowerStatus(SYSTEM_POWER_STATUS result);
}

以下是您可以使用它的方法，例如：在main()方法中：

Kernel32.SYSTEM_POWER_STATUS batteryStatus = new Kernel32.SYSTEM_POWER_STATUS();
Kernel32.INSTANCE.GetSystemPowerStatus(batteryStatus);

System.out.println(batteryStatus); // Shows result of toString() method.

这会在我的Latitude E5500上成功打印以下内容：

ACLineStatus: Online
Battery Flag: High, more than 66 percent
Battery Life: 100%
Battery Left: Unknown
Battery Full: Unknown

在关闭AC 10分钟后：

ACLineStatus: Offline
Battery Flag: High, more than 66 percent
Battery Life: 82%
Battery Left: 2954 seconds
Battery Full: Unknown

（不，没有坏电池，我只是编辑电影并且现在不断通过wifi传输;）

如何在Windows系统中获得剩余电量？

1 个答案: