《android运行时权限处理》

权限在android6.0一个分水岭。在6.0咱们只须要在AndroidManifest.xml文件中去申请权限，这个仍是有点简单的相信你们都明白。而在6.0+则发生了变化。就是某些特殊的权限好比：定位、摄像等。其实这才符合人们的使用习惯，指哪打哪。

既然说了指哪打哪就要咱们动态的去判断一个权限和多个权限是否已经被受权或者没有受权的状况下是否须要弹出框。而ContextCompat中就有一个方法checkSelfPermission来专门来为咱们服务，完成该项工做。具体代码以下

public class PermissionManager {
	
    private Object mObject;
    private String[] mPermissions;
    private int mRequestCode;
    private PermissionListener mListener;
    // 用户是否确认了解释框的
    private boolean mIsPositive = false;

    public static PermissionManager with(Activity activity) {
        return new PermissionManager(activity);
    }

    public static PermissionManager with(Fragment fragment) {
        return new PermissionManager(fragment);
    }

    public PermissionManager permissions(String... permissions) {
        this.mPermissions = permissions;
        return this;
    }

    public PermissionManager addRequestCode(int requestCode) {
        this.mRequestCode = requestCode;
        return this;
    }

    public PermissionManager setPermissionsListener(PermissionListener listener) {
        this.mListener = listener;
        return this;
    }

    public PermissionManager(Object object) {
        this.mObject = object;
    }

    /**请求权限  
     * @return PermissionManager  
     */
    public PermissionManager request() {
        request(mObject, mPermissions, mRequestCode);
        return this;
    }

    private void request(Object object, String[] permissions, int requestCode) {
        // 根据权限集合去查找是否已经受权过
        Map<String, List<String>> map = findDeniedPermissions(getActivity(object), permissions);
        List<String> deniedPermissions = map.get("deny");
        List<String> rationales = map.get("rationale");
        if (deniedPermissions.size() > 0) {
            // 第一次点击deny才调用，mIsPositive是为了防止点确认解释框后调request()递归调onShowRationale
            if (rationales.size() > 0 && mIsPositive == false) {
                if (mListener != null ) {
                    mListener.onShowRationale(rationales.toArray(new String[rationales.size()]));
                }
                return;
            }
            if (object instanceof Activity) {
                ActivityCompat.requestPermissions((Activity) object, deniedPermissions.toArray(new String[deniedPermissions.size()]), requestCode);
            } else if (object instanceof Fragment) {
                ((Fragment) object).requestPermissions(deniedPermissions.toArray(new String[deniedPermissions.size()]), requestCode);
            } else {
                throw new IllegalArgumentException(object.getClass().getName() + " is not supported");
            }
        } else {
            if (mListener != null) {
                mListener.onGranted();
            }
        }
    }

    /**根据requestCode处理响应的权限
     * @param permissions
     * @param results   
     */
    public void onPermissionResult(String[] permissions, int[] results) {
        List<String> deniedPermissions = new ArrayList<String>();
        for (int i = 0; i < results.length; i++) {
            if (results[i] != PackageManager.PERMISSION_GRANTED) {//未受权
                deniedPermissions.add(permissions[i]);
            }
        }
        if (deniedPermissions.size() > 0) {
            if (mListener != null) {
                mListener.onDenied();
            }
        } else {
            if (mListener != null) {
                mListener.onGranted();
            }
        }
    }
    
    private Map<String, List<String>> findDeniedPermissions(Activity activity, String... permissions) {
        Map<String, List<String>> map = new HashMap<String, List<String>>();
        List<String> denyList = new ArrayList<String>();//未受权的权限
        List<String> rationaleList = new ArrayList<String>();//须要显示提示框的权限
        for (String value : permissions) {
            if (ContextCompat.checkSelfPermission(activity, value) != PackageManager.PERMISSION_GRANTED) {
                denyList.add(value);
                if (shouldShowRequestPermissionRationale(value)) {
                    rationaleList.add(value);
                }
            }
        }
        map.put("deny", denyList);
        map.put("rationale", rationaleList);
        return map;
    }

    private Activity getActivity(Object object) {
        if (object instanceof Fragment) {
            return ((Fragment) object).getActivity();
        } else if (object instanceof Activity) {
            return (Activity) object;
        }
        return null;
    }

    /**
     * 当用户拒绝某权限时并点击就再也不提醒的按钮时，下次应用再请求该权限时，须要给出合适的响应（好比给个展现对话框）
     * @param permission
     */
    private boolean shouldShowRequestPermissionRationale(String permission) {
        if (mObject instanceof Activity) {
            return ActivityCompat.shouldShowRequestPermissionRationale((Activity) mObject, permission);
        } else if (mObject instanceof Fragment) {
            return ((Fragment) mObject).shouldShowRequestPermissionRationale(permission);
        } else {
            throw new IllegalArgumentException(mObject.getClass().getName() + " is not supported");
        }
    }

    public void setIsPositive(boolean isPositive) {
        this.mIsPositive = isPositive;
    }
}

还有一个回调接口

public interface PermissionListener {
    /**
     * 用户受权后调用
     */
    public void  onGranted();
    
    /**
     * 用户禁止后调用
     */
    public void  onDenied();
    
    /**是否显示阐述性说明
     * @param permissions 返回须要显示说明的权限数组
     */
    public void onShowRationale(String[] permissions);
}

调用代码：

PermissionManager helper;
helper = PermissionManager.with(MainActivity.this)
        //添加权限请求码
        .addRequestCode(MainActivity.REQUEST_CODE_CAMERA)
        //设置权限，能够添加多个权限
        .permissions(Manifest.permission.CAMERA)
        //设置权限监听器
        .setPermissionsListener(new PermissionListener() {

            @Override
            public void onGranted() {
                //当权限被授予时调用
               Toast.makeText(MainActivity.this, "Camera Permission granted",Toast.LENGTH_LONG).show();
            }

            @Override
            public void onDenied() {
                //用户拒绝该权限时调用
               Toast.makeText(MainActivity.this, "Camera Permission denied",Toast.LENGTH_LONG).show();
            }

            @Override
            public void onShowRationale(String[] permissions) {
                //当用户拒绝某权限时并点击`再也不提醒`的按钮时，下次应用再请求该权限时，须要给出合适的响应（好比,给个展现对话框来解释应用为何须要该权限）
                Snackbar.make(btn_camera, "须要相机权限去拍照", Snackbar.LENGTH_INDEFINITE)
                        .setAction("ok", new View.OnClickListener() {
                            @Override
                            public void onClick(View v) {
                                //必须调用该`setIsPositive(true)`方法
                                helper.setIsPositive(true);
                                helper.request();
                            }
                        }).show();
            }
        })
        //请求权限
        .request();

打完。写得粗糙。请见谅