Android：为requestcode值选择什么？

记录发现结果以备将来参考：

以下是来自的代码

android.support.v4.app.FragmentActivity

 @Overridepublic void startActivityForResult(Intent intent, int requestCode) {    if (requestCode != -1 && (requestCode&0xffff0000) != 0) {        throw new IllegalArgumentException("Can only use lower 16 bits for requestCode");    }    super.startActivityForResult(intent, requestCode);}@Overridepublic final void validateRequestPermissionsRequestCode(int requestCode) {    // We use 16 bits of the request pre to enpre the fragment id when    // requesting permissions from a fragment. Hence, requestPermissions()    // should validate the pre against that but we cannot override it as    // we can not then call super and also the ActivityCompat would call    // back to this override. To handle this we use dependency inversion    // where we are the validator of request pres when requesting    // permissions in ActivityCompat.    if (!mRequestedPermissionsFromFragment && requestCode != -1 && (requestCode & 0xffff0000) != 0) {        throw new IllegalArgumentException("Can only use lower 16 bits for requestCode");    }}

RANGE

startActivityForResult()

FragmentActivity

另外，

validateRequestPermissionsRequestCode

FragmentActivity