现在基于信息安全问题，特别是版本是23以上权限越严格。
特别是拍照，读，写权限
一般权限允许过，下次就不用询问了的，所以很多应用都喜欢在首页或者启动页直接询问，不允许的就用不了
1、下面给出封装好的类，至于什么时候调看项目需要

public class EasyPermissions {

private static final String TAG = "EasyPermissions";

public interface PermissionCallbacks extends
        ActivityCompat.OnRequestPermissionsResultCallback {

    void onPermissionsGranted(List perms);

    void onPermissionsDenied(List perms);

}

/**
 * Check if the calling context has a set of permissions.
 *
 * @param context the calling context.
 * @param perms   one ore more permissions, such as {@code android.Manifest.permission.CAMERA}.
 * @return true if all permissions are already granted, false if at least one permission
 * is not yet granted.
 */
public static boolean hasPermissions(Context context, String... perms) {
    for (String perm : perms) {
        boolean hasPerm = (ContextCompat.checkSelfPermission(context, perm) == PackageManager.PERMISSION_GRANTED);
        if (!hasPerm) {
            return false;
        }
    }

    return true;
}

/**
 * Request a set of permissions, showing rationale if the system requests it.
 *
 * @param object      Activity or Fragment requesting permissions. Should implement
 *                    {@link ActivityCompat.OnRequestPermissionsResultCallback}
 *                    or
 *                    {@link android.support.v13.app.FragmentCompat.OnRequestPermissionsResultCallback}
 * @param rationale   a message explaining why the application needs this set of permissions, will
 *                    be displayed if the user rejects the request the first time.
 * @param requestCode request code to track this request, must be ());
                        }
                    }
                }).create();
        dialog.show();
    } else {
        executePermissionsRequest(object, perms, requestCode);
    }
}

/**
 * Handle the result of a permission request, should be called from the calling Activity's
 * {@link ActivityCompat.OnRequestPermissionsResultCallback#onRequestPermissionsResult(int, String[], int[])}
 * method.
 * 

 * If any permissions were granted or denied, the Activity will receive the appropriate
 * callbacks through {@link PermissionCallbacks} and methods annotated with
 * {@link AfterPermissionGranted} will be run if appropriate.
 *
 * @param requestCode  requestCode argument to permission result callback.
 * @param permissions  permissions argument to permission result callback.
 * @param grantResults grantResults argument to permission result callback.
 * @param object       the calling Activity or Fragment.
 * @throws IllegalArgumentException if the calling Activity does not implement
 *                                  {@link PermissionCallbacks}.
 */
public static void onRequestPermissionsResult(int requestCode, String[] permissions,
        int[] grantResults, Object object) {

    checkCallingObjectSuitability(object);
    PermissionCallbacks callbacks = (PermissionCallbacks) object;

    // Make a collection of granted and denied permissions from the request.
    ArrayList granted = new ArrayList();
    ArrayList denied = new ArrayList();
    for (int i = 0; i  0) {
                    throw new RuntimeException("Cannot execute non-void method " + method.getName());
                }

                try {
                    // Make method accessible if private
                    if (!method.isAccessible()) {
                        method.setAccessible(true);
                    }
                    method.invoke(object);
                } catch (IllegalAccessException e) {
                    ILogger.e(TAG, "runDefaultMethod:IllegalAccessException", e);
                } catch (InvocationTargetException e) {
                    ILogger.e(TAG, "runDefaultMethod:InvocationTargetException", e);
                }
            }
        }
    }
}

private static void checkCallingObjectSuitability(Object object) {
    // Make sure Object is an Activity or Fragment
    if (!((object instanceof Fragment) || (object instanceof Activity))) {
        throw new IllegalArgumentException("Caller must be an Activity or a Fragment.");
    }

    // Make sure Object implements callbacks
    if (!(object instanceof PermissionCallbacks)) {
        throw new IllegalArgumentException("Caller must implement PermissionCallbacks.");
    }
}}

注：这个类不是我写的，分享给大家
2、调用示例（activity或fragment）：（方法调用的时机随你）

private void requestGalleryPermission() {
    //权限参数可以添加很多，不固定参数的
    if (EasyPermissions.hasPermissions(this, Manifest.permission.READ_EXTERNAL_STORAGE,Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
        getPhotos();//如果具有权限做的操作
    } else {
        // Ask for one permission
        EasyPermissions.requestPermissions(this, getString(R.string.permissions_tips_gallery),
                GalleryFinal.PERMISSIONS_CODE_GALLERY, Manifest.permission.READ_EXTERNAL_STORAGE,Manifest.permission.WRITE_EXTERNAL_STORAGE);
    }
}

3、拒绝和允许做的操作（activity或fragment）：

@Override
public void onPermissionsGranted(List list) {
    //允许
    getPhotos();
}

@Override
public void onPermissionsDenied(List list) {
    //拒绝
    mTvEmptyView.setText(R.string.permissions_denied_tips);
    //mIvTakePhoto.setVisibility(View.GONE);
}