如何检查 SDK 版本的电话和摄像头可用性 <5 [英] How to check telephony and camera availability for SDK version < 5

问题描述

检查相机和电话硬件可用性的标准方法仅在 SDK >= 5 后才有效:

Standard way of checking camera and telephony hardware availability works only since SDK >= 5:

PackageManager pm = this.getPackageManager();
boolean hasTelephony=pm.hasSystemFeature(PackageManager.FEATURE_TELEPHONY);
boolean hasCamera=pm.hasSystemFeature(PackageManager.FEATURE_CAMERA);

我需要在 SDK 3 (Android 1.5) 中运行时定义电话和摄像头的可用性的问题

My problem that I need to runtime define availability of telephony and camera in SDK 3 (Android 1.5)

有什么想法吗?

P.S.我知道 Android 1.5 已经过时了，但我仍然有很多客户在使用这些设备，所以我必须保持与它们的兼容性.

P.S. I understand that Android 1.5 is very outdated, but still I do have bunch of customers running these devices, so I have to keep compatibility with them.

推荐答案

好吧，我找到了解决方案 - 非常奇怪，但它正在工作.

Well, I have found solution - very odd but it's working.

如果它为 null，则基本上方法会尝试获取电话服务 - 如果它不为 null(例如，对于 HTC Flyer TelephonyManager 不为 null)，则返回 false 方法尝试运行 PackageManager.hasSystemFeature(PackageManager.FEATURE_TELEPHONY) 使用反射，因为此方法不适用于旧版本的 SDK.

Basically method tries to get telephony service if it's null - it returns false, if it's not null (e.g. for HTC Flyer TelephonyManager is not null) method tries to run PackageManager.hasSystemFeature(PackageManager.FEATURE_TELEPHONY) using reflection, since this method is not available for old versions of SDK.

这是一个代码:

private Boolean hasTelephony;

public boolean hasTelephony()
{
    if(hasTelephony==null)
    {
        TelephonyManager tm=(TelephonyManager )this.getSystemService(Context.TELEPHONY_SERVICE);
        if(tm==null)
        {
            hasTelephony=new Boolean(false);
            return hasTelephony.booleanValue();
        }
        if(this.getSDKVersion() < 5)
        {
            hasTelephony=new Boolean(true);
            return hasTelephony;
        }
        PackageManager pm = this.getPackageManager();
        Method method=null;
        if(pm==null)
            return hasCamera=new Boolean(false);
        else
        {
            try
            {
                Class[] parameters=new Class[1];
                parameters[0]=String.class;
                method=pm.getClass().getMethod("hasSystemFeature", parameters);
                Object[] parm=new Object[1];
                parm[0]=new String(PackageManager.FEATURE_TELEPHONY);
                Object retValue=method.invoke(pm, parm);
                if(retValue instanceof Boolean)
                    hasTelephony=new Boolean(((Boolean )retValue).booleanValue());
                else
                    hasTelephony=new Boolean(false);
            }
            catch(Exception e)
            {
                hasTelephony=new Boolean(false);
            }
        }
    }
    return hasTelephony;
}

或多或少相同的方法可用于检查相机可用性

More or less the same approach is workable for checking of camera availability

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