Android M是Google在15年中旬发布的新版本，相信开发者都不陌生了，Android 6.0其实就是多了个省电和安全（运行时权限）嘛
为什么现在还拿运行时权限出来老生常谈一下呢，因为针对Android M的运行时权限处理其实是小众需求，一般不关心手机内置的应用只要targetSDK在23以下就解决Android M运行时权限适配这个让开发人员无比蛋疼的问题了
可是针对需要进行Android M运行时权限适配的应用来说你需要关心以下事情了
1.直入主题
- 这里就不写一堆运行时权限的介绍和官方API了,想了解的可以看我同事的相关文章：传送门
- 当然市场上也有使用响应式编程的解决框架：RxPermissions
所以本文针对的是不想用Rx编程，且想解决的更加简单更加符合用户完整体验的同学
在做运行时权限适配的时候你一定会遇到以下问题
- 1.现有代码怎么办？
- 2.怎么简单解决？
- 2.怎么不影响代码的可读性？
- 3.没有权限的时候怎么办？/怎么容错，怎么不导致功能缺失
那先来看下我认为的完整的运行时权限处理的流程图
流程图-Android M运行时权限
不是我故意复杂的，多一个无权限的引导是我认为的用户行为的闭环，一般我们就是提示一个SnackBar也不会干扰用户，当然你可以选择不用这一部分流程
2.实现逻辑
最先考虑怎么基于现有代码简单的不影响可读性的实现的时候，首先就想到了Action，如果你熟知RxAndroid响应式编程的话你一定比较熟悉,但是我这里将Action做成了一个类似责任链的方式
Talk is cheap , Show me the code.
- ***IAction ***
public abstract class IAction {
private IAction mParent;
private IAction mChild;
public IAction() {
}
final public boolean run() {
if (mParent != null && mParent.run()) {
return true;
}
return call();
}
/**
* @return if return true interrupt
*/
abstract public boolean call();
public void onError() {
if (getChild() != null) {
getChild().onError();
}
}
public IAction setParent(IAction parent) {
this.mParent = parent;
if (parent != null) {
parent.setChild(this);
}
return this;
}
final public IAction getParent() {
return mParent;
}
final protected void setChild(IAction child) {
mChild = child;
}
final public IAction getChild() {
return mChild;
}
public IAction getLastChild() {
if (mChild == null) {
return this;
} else {
return mChild.getLastChild();
}
}
}
这样设计的优势是便于封装现有代码，且单元性好能够很好能够任意组合（等会看到实现处你就会爱上它了）
- IPermissionAction
具体的运行时权限的逻辑处理类
public abstract class IPermissionAction extends IAction implements InnerOnRequestPermissionsResult {
private final int mRequestCode;
private String mRequestPermission;
private Activity mActivity;
public boolean isNeedRequestPermission = true;
public IPermissionAction(Activity activity) {
mActivity = activity;
mRequestPermission = getRequestPermission();
if (TextUtils.isEmpty(mRequestPermission)) {
mRequestCode = 0;
} else {
mRequestCode = Math.abs(mRequestPermission.hashCode());
}
}
public abstract String getRequestPermission();
public void isNeedRequestPermission(boolean isNeedRequestPermission) {
this.isNeedRequestPermission = isNeedRequestPermission;
}
@Override
final public boolean call() {
if (mRequestCode == 0) {
return false;
}
if (Build.VERSION.SDK_INT < 23) {
return false;
}
int permissionCheck = ContextCompat.checkSelfPermission(mActivity, mRequestPermission);
if (permissionCheck == PackageManager.PERMISSION_GRANTED) {
//版本小于23 或者 有权限时
return false;
} else if (permissionCheck == PackageManager.PERMISSION_DENIED) {
doRequestPermission();
onPermissionUnable();
return true;
}
return false;
}
@TargetApi(23)
final private void doRequestPermission() {
try {
if (isNeedRequestPermission) {
LLog.e(mRequestPermission + " requestPermissions : " + mRequestCode);
mActivity.requestPermissions(new String[]{mRequestPermission}, mRequestCode);
RunTimePermissionManager.getInstance().addOnActivityPermissionsResults(this);
}
} catch (Throwable e) {
e.printStackTrace();
}
}
@Override
final public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
if (requestCode == mRequestCode) {
RunTimePermissionManager.getInstance().removeOnActivityPermissionsResults(this);
if (permissions != null && permissions.length > 0 && mRequestPermission.equals(permissions[0])) {
if (grantResults != null && grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
LLog.e(permissions[0] + " permission allowed");
getLastChild().run();
return;
}
}
if (ActivityCompat.shouldShowRequestPermissionRationale(mActivity, mRequestPermission)) {
onPermissionDenied();
} else {
onPermissionAlwaysDenied();
}
}
}
protected void onPermissionAlwaysDenied() {
LLog.e(mRequestPermission + " onPermissionAlwaysDenied");
}
protected void onPermissionDenied() {
LLog.e(mRequestPermission + " onPermissionDenied");
}
protected void onPermissionUnable() {
LLog.e(mRequestPermission + " onPermissionUnable");
}
}
- RunTimePermissionManager
这个单例是为了接收和处理Activity的onRequestPermissionsResult的事件
public class RunTimePermissionManager {
private static RunTimePermissionManager mInstance;
private ArrayList<InnerOnRequestPermissionsResult> mPermissionsResults = new ArrayList<>();
private ArrayList<InnerOnRequestPermissionsResult> mRemovedPermissionsResults = new ArrayList<>();
private RunTimePermissionManager() {
}
public static RunTimePermissionManager getInstance() {
if (mInstance == null) {
mInstance = new RunTimePermissionManager();
}
return mInstance;
}
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
if (mPermissionsResults != null) {
LLog.e("onRequestPermissionsResult : " + requestCode);
for (int i = 0; i < mPermissionsResults.size(); i++) {
LLog.e("mPermissionsResults : " + i + " " + mPermissionsResults.get(i).toString());
InnerOnRequestPermissionsResult mPermissionsResult = mPermissionsResults.get(i);
if (mPermissionsResult != null) {
LLog.e("onRequestPermissionsResult goto: " + requestCode);
mPermissionsResult.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
if (mRemovedPermissionsResults != null && mRemovedPermissionsResults.size() > 0) {
if (mPermissionsResults.removeAll(mRemovedPermissionsResults)) {
mRemovedPermissionsResults.clear();
}
}
}
}
public void addOnActivityPermissionsResults(InnerOnRequestPermissionsResult innerOnRequestPermissionsResult) {
if (mPermissionsResults != null) {
mPermissionsResults.add(innerOnRequestPermissionsResult);
}
}
public void removeOnActivityPermissionsResults(InnerOnRequestPermissionsResult innerOnRequestPermissionsResult) {
if (mPermissionsResults != null && mRemovedPermissionsResults != null) {
mRemovedPermissionsResults.add(innerOnRequestPermissionsResult);
}
}
}
- InnerOnRequestPermissionsResult
将Activity的方法提取成接口
public interface InnerOnRequestPermissionsResult {
void onRequestPermissionsResult(int var1, String[] var2, int[] var3);
}
对！实现一共就4个类,下面是Demo
Activity的入口可以写在BaseActivity里面，当然不然你也可以在每一个需要的Activity里面加这行
public class BaseActivity extends Activity {
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
RunTimePermissionManager.getInstance().onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
- 具体代码实现处
new IAction() {
@Override
public boolean call() {
//权限保护的代码，原本逻辑代码
return false;
}
}.setParent(new IPermissionAction(DemoActivity.this) {
@Override
public String getRequestPermission() {
//需要申请的权限
return Manifest.permission.WRITE_EXTERNAL_STORAGE;
}
}).run();
当一个复杂功能逻辑可能需要多个权限的时候，你只要写多几个IPermissionAction就可以了，之后你需要的权限交互方面，你只要在IPermissionAction的
onPermissionAlwaysDenied（）
onPermissionDenied（）
onPermissionUnable（）
方法中处理就好了。
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