unity AndroidJavaObject,call 没有return吗
时间: 2023-08-19 12:04:53 浏览: 35
Unity 中的 AndroidJavaObject 类的 call() 方法,可以调用 Java 层的方法,并获取返回值,例如:
```csharp
AndroidJavaObject activity = new AndroidJavaClass("com.unity3d.player.UnityPlayer").GetStatic<AndroidJavaObject>("currentActivity");
AndroidJavaObject intent = new AndroidJavaObject("android.content.Intent", activity, typeof(AndroidJavaObject));
intent.Call<AndroidJavaObject>("putExtra", "key", "value");
AndroidJavaObject result = intent.Call<AndroidJavaObject>("getStringExtra", "key");
string value = result.Call<string>("toString");
```
在上面的代码中,我们调用了 intent 对象的 putExtra() 方法和 getStringExtra() 方法,putExtra() 方法没有返回值,而 getStringExtra() 方法返回一个 String 类型的值。因此,我们通过 Call() 方法获取返回值,然后再使用返回值调用对应的方法,从而获取最终的结果。
相关问题
Unity 获取Android 的 USB权限
在Unity中获取Android的USB权限需要使用Android的Java层代码,可以通过Unity的AndroidJavaObject类来调用Java代码实现。以下是获取USB权限的示例代码:
```csharp
private void GetUsbPermission()
{
AndroidJavaObject context = new AndroidJavaClass("com.unity3d.player.UnityPlayer").GetStatic<AndroidJavaObject>("currentActivity").Call<AndroidJavaObject>("getApplicationContext");
AndroidJavaObject usbManager = context.Call<AndroidJavaObject>("getSystemService", "usb");
AndroidJavaObject usbDevice = GetUsbDevice();
if (usbDevice != null)
{
AndroidJavaObject pendingIntent = AndroidJavaObject("android.app.PendingIntent").CallStatic<AndroidJavaObject>("getBroadcast", context, 0, new AndroidJavaObject("android.content.Intent"), 0);
AndroidJavaObject intentFilter = AndroidJavaObject("android.content.IntentFilter").CallStatic<AndroidJavaObject>("create", "android.hardware.usb.action.USB_DEVICE_ATTACHED");
AndroidJavaObject broadcastReceiver = new AndroidJavaObject("android.content.BroadcastReceiver");
broadcastReceiver.Call("onReceive", context, new AndroidJavaObject("android.content.Intent"));
context.Call("registerReceiver", broadcastReceiver, intentFilter);
usbManager.Call("requestPermission", usbDevice, pendingIntent);
}
}
private AndroidJavaObject GetUsbDevice()
{
AndroidJavaObject context = new AndroidJavaClass("com.unity3d.player.UnityPlayer").GetStatic<AndroidJavaObject>("currentActivity").Call<AndroidJavaObject>("getApplicationContext");
AndroidJavaObject usbManager = context.Call<AndroidJavaObject>("getSystemService", "usb");
AndroidJavaObject usbDevice = null;
AndroidJavaObject deviceList = usbManager.Call<AndroidJavaObject>("getDeviceList");
AndroidJavaObject[] deviceArray = AndroidJNIHelper.ConvertFromJNIArray<AndroidJavaObject[]>(deviceList.GetRawObject());
foreach (AndroidJavaObject device in deviceArray)
{
int deviceClass = device.Call<int>("getDeviceClass");
int deviceSubClass = device.Call<int>("getDeviceSubclass");
if (deviceClass == 0x02 && deviceSubClass == 0x01)
{
usbDevice = device;
break;
}
}
return usbDevice;
}
```
这段代码主要包括两个方法:
1. `GetUsbDevice()`:获取连接的USB设备,判断设备的类型是否为USB存储设备。
2. `GetUsbPermission()`:获取USB权限,注册USB设备连接广播,请求USB权限。
需要注意的是,这段代码只是示例代码,具体的实现需要根据实际情况进行修改和优化。
unity获取安卓电量
你可以使用以下 C# 代码来获取安卓设备的电量:
```csharp
using UnityEngine;
using System.Collections;
public class BatteryLevel : MonoBehaviour {
void Start () {
StartCoroutine ("GetBatteryLevel");
}
IEnumerator GetBatteryLevel () {
// 等待一帧
yield return null;
// 获取电量
float batteryLevel = -1;
try {
// 获取电池状态的 Java 类
AndroidJavaClass unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
AndroidJavaObject context = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity").Call<AndroidJavaObject>("getApplicationContext");
AndroidJavaObject intent = context.Call<AndroidJavaObject>("registerReceiver", null, new AndroidJavaObject("android.content.IntentFilter", new object[]{"android.intent.action.BATTERY_CHANGED"}));
int level = intent.Call<int>("getIntExtra", new AndroidJavaObject("java.lang.String", "level"), -1);
int scale = intent.Call<int>("getIntExtra", new AndroidJavaObject("java.lang.String", "scale"), -1);
batteryLevel = (float)level / (float)scale;
} catch (System.Exception e) {
Debug.Log ("Failed to get battery level: " + e.Message);
}
Debug.Log ("Battery level: " + batteryLevel);
}
}
```
这个脚本会在 Unity 中输出设备的电量。请注意,此代码仅在安卓设备上可用。如果您在 iOS 上运行此代码,它将不起作用。