--- # 前言 EasyPermissions是检查和申请Android动态权限的库，简化了原生权限逻辑。使用方法参照[官方文档](https://github.com/googlesamples/easypermissions)。 --- # 一、需求 **需要对库里面封装了2个提示弹框替换成app内部统一的设计式样，分别是：** - 提示框1: 用户拒绝权限后提示。

- 提示框2: 用户拒绝权限且选择以后都不再询问时提示，在收到拒绝回调时show出内置的AppSettingsDialog。 ```java @Override public void onPermissionsDenied(int requestCode, List perms) { Log.d(TAG, "onPermissionsDenied:" + requestCode + ":" + perms.size()); // (Optional) Check whether the user denied any permissions and checked "NEVER ASK AGAIN." // This will display a dialog directing them to enable the permission in app settings. if (EasyPermissions.somePermissionPermanentlyDenied(this, perms)) { new AppSettingsDialog.Builder(this).build().show(); } } ```

点击确定键会跳转到设置中的应用信息方便更改权限 ```java public void onClick(DialogInterface dialog, int which) { if (which == Dialog.BUTTON_POSITIVE) { Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS) .setData(Uri.fromParts("package", getPackageName(), null)); intent.addFlags(mIntentFlags); startActivityForResult(intent, APP_SETTINGS_RC); } else if (which == Dialog.BUTTON_NEGATIVE) { setResult(Activity.RESULT_CANCELED); finish(); } else { throw new IllegalStateException("Unknown button type: " + which); } } ``` # 二、实现 1. 提示框2很好替换，把AppSettingsDialog替换成自己的Dialog就可以了。 ```kotlin override fun onPermissionsDenied(requestCode: Int, perms: List) { if (EasyPermissions.somePermissionPermanentlyDenied(this, perms)) { CommonDialog.Builder(this).build().show() } } ```

2. 提示框1没找到公开能替换的方法。请求权限时的调用： ```java private fun requestPermission(vararg perms: String) { val request = PermissionRequest.Builder(this, REQUEST_CODE_PERMISSIONS, *perms) .setRationale("This app may not work correctly without the requested permissions.") .setPositiveButtonText("确定") .setNegativeButtonText("取消") .build() EasyPermissions.requestPermissions(request) } ``` 先看一下源码，通过PermissionRequest的getHelper()取到PermissionHelper，然后调用的requestPermissions方法申请权限 ```java public static void requestPermissions(PermissionRequest request) { // Check for permissions before dispatching the request if (hasPermissions(request.getHelper().getContext(), request.getPerms())) { notifyAlreadyHasPermissions( request.getHelper().getHost(), request.getRequestCode(), request.getPerms()); return; } // Request permissions request.getHelper().requestPermissions( request.getRationale(), request.getPositiveButtonText(), request.getNegativeButtonText(), request.getTheme(), request.getRequestCode(), request.getPerms()); } ``` PermissionHelper是在创建PermissionRequest时创建的 ```java public Builder(@NonNull Activity activity, int requestCode, @NonNull @Size(min = 1) String... perms) { mHelper = PermissionHelper.newInstance(activity); mRequestCode = requestCode; mPerms = perms; } public Builder(@NonNull Fragment fragment, int requestCode, @NonNull @Size(min = 1) String... perms) { mHelper = PermissionHelper.newInstance(fragment); mRequestCode = requestCode; mPerms = perms; } ``` PermissionHelper调用showRequestPermissionRationale显示弹框 ```java public void requestPermissions(@NonNull String rationale, @NonNull String positiveButton, @NonNull String negativeButton, @StyleRes int theme, int requestCode, @NonNull String... perms) { if (shouldShowRationale(perms)) { showRequestPermissionRationale( rationale, positiveButton, negativeButton, theme, requestCode, perms); } else { directRequestPermissions(requestCode, perms); } } ``` PermissionHelper是个抽象类，继承关系如下

找个BaseSupportPermissionsHelper的showRequestPermissionRationale方法看一下 ```java public void showRequestPermissionRationale(@NonNull String rationale, @NonNull String positiveButton, @NonNull String negativeButton, @StyleRes int theme, int requestCode, @NonNull String... perms) { FragmentManager fm = getSupportFragmentManager(); // Check if fragment is already showing Fragment fragment = fm.findFragmentByTag(RationaleDialogFragmentCompat.TAG); if (fragment instanceof RationaleDialogFragmentCompat) { Log.d(TAG, "Found existing fragment, not showing rationale."); return; } RationaleDialogFragmentCompat .newInstance(rationale, positiveButton, negativeButton, theme, requestCode, perms) .showAllowingStateLoss(fm, RationaleDialogFragmentCompat.TAG); } ``` RationaleDialogFragmentCompat继承自DialogFragment ```java @Override public Dialog onCreateDialog(Bundle savedInstanceState) { // Rationale dialog should not be cancelable setCancelable(false); // Get config from arguments, create click listener RationaleDialogConfig config = new RationaleDialogConfig(getArguments()); RationaleDialogClickListener clickListener = new RationaleDialogClickListener(this, config, mPermissionCallbacks, mRationaleCallbacks); // Create an AlertDialog return config.createSupportDialog(getContext(), clickListener); } ``` RationaleDialogConfig: ```java AlertDialog createSupportDialog(Context context, Dialog.OnClickListener listener) { AlertDialog.Builder builder; if (theme > 0) { builder = new AlertDialog.Builder(context, theme); } else { builder = new AlertDialog.Builder(context); } return builder .setCancelable(false) .setPositiveButton(positiveButton, listener) .setNegativeButton(negativeButton, listener) .setMessage(rationaleMsg) .create(); } ``` 从上面看是可以把源码下载一份替换默认的AlertDialog后打包使用的，这个就不多说了。这里采用了另外一个方案：可以hook替换PermissionRequest的mHelper ```java private final PermissionHelper mHelper; ``` 更改mHelper的showRequestPermissionRationale方法来弹出自己的Dialog，先定义一个代理类： ```kotlin public class PermissionsHelperProxy( private val permissionHelper: BaseSupportPermissionsHelper ) : BaseSupportPermissionsHelper(permissionHelper.host!!) { override fun directRequestPermissions(requestCode: Int, vararg perms: String?) { permissionHelper.directRequestPermissions(requestCode, *perms) } override fun shouldShowRequestPermissionRationale(perm: String): Boolean { return permissionHelper.shouldShowRequestPermissionRationale(perm) } override fun getContext(): Context { return permissionHelper.context } override fun getSupportFragmentManager(): FragmentManager { return permissionHelper.supportFragmentManager } override fun showRequestPermissionRationale( rationale: String, positiveButton: String, negativeButton: String, @StyleRes theme: Int, requestCode: Int, vararg perms: String ) { CommonDialog.Builder(context).build().show() } ``` 在请求权限时替换： ```kotlin private fun requestPermission(vararg perms: String) { val request = PermissionRequest.Builder(this, REQUEST_CODE_PERMISSIONS, *perms) .setRationale("This app may not work correctly without the requested permissions.") .setPositiveButtonText("确定") .setNegativeButtonText("取消") .build() try { val clazz = request.javaClass val field = clazz.getDeclaredField("mHelper") field.isAccessible = true val permissionHelper = field.get(request) as BaseSupportPermissionsHelper field.set(request, PermissionsHelperProxy(permissionHelper)) } catch (e: Exception) { } EasyPermissions.requestPermissions(request) } ``` 成功：