对android权限管理的一点小总结

一、检查应用是否拥有某个权限

在android6.0以前的方式

PackageManager pm = getPackageManager();  
boolean permission = (PackageManager.PERMISSION_GRANTED ==pm.checkPermission("android.permission.RECORD_AUDIO", "packageName"));  

在android6.0以后的方式

boolean permission = ContextCompat.checkSelfPermission(mContext, permission) == PackageManager.PERMISSION_DENIED;

或者还可以用V4包中提供的函数

boolean permission = PermissionChecker.checkSelfPermission(context, permission) == PackageManager.PERMISSION_GRANTED;

在6.0以前，很多权限在Manifest.xml中声明了就代表应用已经拥有了该项权限，所以即使去《设置》中手动静止该项权限，ContextCompat.checkSelfPermission函数返回的值永远都等于PackageManager.PERMISSION_DENIED。所以在6.0以前的系统如果手动静止了， 就没法用这个函数来做判断，只能再去手动打开权限。

二、申请权限

ActivityCompat.requestPermissions(thisActivity,new String[]{Manifest.permission.READ_CONTACTS},  MY_PERMISSIONS_REQUEST_READ_CONTACTS);

处理权限申请回掉

@Override
public void onRequestPermissionsResult(int requestCode,String permissions[], int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_READ_CONTACTS: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                 // permission was granted, yay! Do the
                 // contacts-related task you need to do.
            } else {
                // permission denied, boo! Disable the
                // functionality that depends on this permission.
            }
            return;
        }
    }
}

当用户拒绝过一次权限申请了，当再一次申请权限时，需要给用户一个解释为什么要申请该权限，调用以下代码

ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,Manifest.permission.READ_CONTACTS)
例如：
    // Should we show an explanation?
    if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity, Manifest.permission.READ_CONTACTS)) {
        // Show an expanation to the user *asynchronously* -- don't block
        // this thread waiting for the user's response! After the user
        // sees the explanation, try again to request the permission.
    } else {
        // No explanation needed, we can request the permission.
        ActivityCompat.requestPermissions(thisActivity, new String[]{Manifest.permission.READ_CONTACTS}, MY_PERMISSIONS_REQUEST_READ_CONTACTS);
    }

结语：随着版本的升级，Google在android手机的安全处理上也在不断的完善，更好的保护用户手机的安全。 用户的安全是保障了，程序员的工作复杂程度也会越来越高，需要不断的更新自己的知识库，才能不被淘汰，加油！！