实现路由跳转 - Xiasm/EasyRouter GitHub Wiki
通过上节的介绍，我们知道在初始化的时候已经拿到了所有的路由信息，那么实现跳转便好做了。
@Route(path = "/main/main")
public class MainActivity extends AppCompatActivity {
public void startModule1MainActivity(View view) {
EasyRouter.getsInstance().build("/module1/module1main").navigation();
}
}
在build的时候，传入要跳转的路由地址，build()方法会返回一个Postcard对象，我们称之为跳卡。然后调用Postcard的navigation()方法完成跳转。用过ARouter的对这个跳卡都应该很熟悉吧！Postcard里面保存着跳转的信息。下面我把Postcard类的代码实现粘下来：
public class Postcard extends RouteMeta {
private Bundle mBundle;
private int flags = -1;
//新版风格
private Bundle optionsCompat;
//老版
private int enterAnim;
private int exitAnim;
//服务
private IService service;
public Postcard(String path, String group) {
this(path, group, null);
}
public Postcard(String path, String group, Bundle bundle) {
setPath(path);
setGroup(group);
this.mBundle = (null == bundle ? new Bundle() : bundle);
}
public Bundle getExtras() {return mBundle;}
public int getEnterAnim() {return enterAnim;}
public int getExitAnim() {return exitAnim;}
public IService getService() {
return service;
}
public void setService(IService service) {
this.service = service;
}
/**
* Intent.FLAG_ACTIVITY**
* @param flag
* @return
*/
public Postcard withFlags(int flag) {
this.flags = flag;
return this;
}
public int getFlags() {
return flags;
}
/**
* 跳转动画
*
* @param enterAnim
* @param exitAnim
* @return
*/
public Postcard withTransition(int enterAnim, int exitAnim) {
this.enterAnim = enterAnim;
this.exitAnim = exitAnim;
return this;
}
/**
* 转场动画
*
* @param compat
* @return
*/
public Postcard withOptionsCompat(ActivityOptionsCompat compat) {
if (null != compat) {
this.optionsCompat = compat.toBundle();
}
return this;
}
public Postcard withString(@Nullable String key, @Nullable String value) {
mBundle.putString(key, value);
return this;
}
public Postcard withBoolean(@Nullable String key, boolean value) {
mBundle.putBoolean(key, value);
return this;
}
public Postcard withShort(@Nullable String key, short value) {
mBundle.putShort(key, value);
return this;
}
public Postcard withInt(@Nullable String key, int value) {
mBundle.putInt(key, value);
return this;
}
public Postcard withLong(@Nullable String key, long value) {
mBundle.putLong(key, value);
return this;
}
public Postcard withDouble(@Nullable String key, double value) {
mBundle.putDouble(key, value);
return this;
}
public Postcard withByte(@Nullable String key, byte value) {
mBundle.putByte(key, value);
return this;
}
public Postcard withChar(@Nullable String key, char value) {
mBundle.putChar(key, value);
return this;
}
public Postcard withFloat(@Nullable String key, float value) {
mBundle.putFloat(key, value);
return this;
}
public Postcard withParcelable(@Nullable String key, @Nullable Parcelable value) {
mBundle.putParcelable(key, value);
return this;
}
public Postcard withStringArray(@Nullable String key, @Nullable String[] value) {
mBundle.putStringArray(key, value);
return this;
}
public Postcard withBooleanArray(@Nullable String key, boolean[] value) {
mBundle.putBooleanArray(key, value);
return this;
}
public Postcard withShortArray(@Nullable String key, short[] value) {
mBundle.putShortArray(key, value);
return this;
}
public Postcard withIntArray(@Nullable String key, int[] value) {
mBundle.putIntArray(key, value);
return this;
}
public Postcard withLongArray(@Nullable String key, long[] value) {
mBundle.putLongArray(key, value);
return this;
}
public Postcard withDoubleArray(@Nullable String key, double[] value) {
mBundle.putDoubleArray(key, value);
return this;
}
public Postcard withByteArray(@Nullable String key, byte[] value) {
mBundle.putByteArray(key, value);
return this;
}
public Postcard withCharArray(@Nullable String key, char[] value) {
mBundle.putCharArray(key, value);
return this;
}
public Postcard withFloatArray(@Nullable String key, float[] value) {
mBundle.putFloatArray(key, value);
return this;
}
public Postcard withParcelableArray(@Nullable String key, @Nullable Parcelable[] value) {
mBundle.putParcelableArray(key, value);
return this;
}
public Postcard withParcelableArrayList(@Nullable String key, @Nullable ArrayList<? extends
Parcelable> value) {
mBundle.putParcelableArrayList(key, value);
return this;
}
public Postcard withIntegerArrayList(@Nullable String key, @Nullable ArrayList<Integer> value) {
mBundle.putIntegerArrayList(key, value);
return this;
}
public Postcard withStringArrayList(@Nullable String key, @Nullable ArrayList<String> value) {
mBundle.putStringArrayList(key, value);
return this;
}
public Bundle getOptionsBundle() {
return optionsCompat;
}
public Object navigation() {
return EasyRouter.getsInstance().navigation(null, this, -1, null);
}
public Object navigation(Context context) {
return EasyRouter.getsInstance().navigation(context, this, -1, null);
}
public Object navigation(Context context, NavigationCallback callback) {
return EasyRouter.getsInstance().navigation(context, this, -1, callback);
}
public Object navigation(Context context, int requestCode) {
return EasyRouter.getsInstance().navigation(context, this, requestCode, null);
}
public Object navigation(Context context, int requestCode, NavigationCallback callback) {
return EasyRouter.getsInstance().navigation(context, this, requestCode, callback);
}
}
如果你是一个Android开发，Postcard类里面的东西就不用我再给你介绍了吧！（哈哈）我相信你一看就明白了。我们只介绍一个方法navigation()，他有好几个重载方法，方法里面会调用EasyRouter类的navigation()方法。EaseRouter的navigation()方法，就是跳转的核心了。下面请看：
protected Object navigation(Context context, final Postcard postcard, final int requestCode, final NavigationCallback callback) {
try {
prepareCard(postcard);
}catch (NoRouteFoundException e) {
e.printStackTrace();
//没找到
if (null != callback) {
callback.onLost(postcard);
}
return null;
}
if (null != callback) {
callback.onFound(postcard);
}
switch (postcard.getType()) {
case ACTIVITY:
final Context currentContext = null == context ? mContext : context;
final Intent intent = new Intent(currentContext, postcard.getDestination());
intent.putExtras(postcard.getExtras());
int flags = postcard.getFlags();
if (-1 != flags) {
intent.setFlags(flags);
} else if (!(currentContext instanceof Activity)) {
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
}
mHandler.post(new Runnable() {
@Override
public void run() {
//可能需要返回码
if (requestCode > 0) {
ActivityCompat.startActivityForResult((Activity) currentContext, intent,
requestCode, postcard.getOptionsBundle());
} else {
ActivityCompat.startActivity(currentContext, intent, postcard
.getOptionsBundle());
}
if ((0 != postcard.getEnterAnim() || 0 != postcard.getExitAnim()) &&
currentContext instanceof Activity) {
//老版本
((Activity) currentContext).overridePendingTransition(postcard
.getEnterAnim()
, postcard.getExitAnim());
}
//跳转完成
if (null != callback) {
callback.onArrival(postcard);
}
}
});
break;
case ISERVICE:
return postcard.getService();
default:
break;
}
return null;
}
这个方法里先去调用了prepareCard(postcard)方法，prepareCard(postcard)代码我贴出来，
private void prepareCard(Postcard card) {
RouteMeta routeMeta = Warehouse.routes.get(card.getPath());
if (null == routeMeta) {
Class<? extends IRouteGroup> groupMeta = Warehouse.groupsIndex.get(card.getGroup());
if (null == groupMeta) {
throw new NoRouteFoundException("没找到对应路由：分组=" + card.getGroup() + " 路径=" + card.getPath());
}
IRouteGroup iGroupInstance;
try {
iGroupInstance = groupMeta.getConstructor().newInstance();
} catch (Exception e) {
throw new RuntimeException("路由分组映射表记录失败.", e);
}
iGroupInstance.loadInto(Warehouse.routes);
//已经准备过了就可以移除了 (不会一直存在内存中)
Warehouse.groupsIndex.remove(card.getGroup());
//再次进入 else
prepareCard(card);
} else {
//类 要跳转的activity 或IService实现类
card.setDestination(routeMeta.getDestination());
card.setType(routeMeta.getType());
switch (routeMeta.getType()) {
case ISERVICE:
Class<?> destination = routeMeta.getDestination();
IService service = Warehouse.services.get(destination);
if (null == service) {
try {
service = (IService) destination.getConstructor().newInstance();
Warehouse.services.put(destination, service);
} catch (Exception e) {
e.printStackTrace();
}
}
card.setService(service);
break;
default:
break;
}
}
}
注意，Warehouse就是专门用来存放路由映射关系的类，这在ARouter里面也是。这段代码Warehouse.routes.get(card.getPath())通过path拿到对应的RouteMeta，这个RouteMeta里面保存了activityClass等信息。继续往下看，如果判断拿到的RouteMeta是空，说明这个路由地址还没有加载到map里面(为了效率，这里是用了懒加载)，只有在第一次用到当前路由地址的时候，会去Warehouse.routes里面拿routeMeta，如果拿到的是空，会根据当前路由地址的group拿到对应的分组，通过反射创建实例，然后调用实例的loadInfo方法，把它里面保存的映射信息添加到Warehouse.routes里面，并且再次调用prepareCard(card)，这时再通过Warehouse.routes.get(card.getPath())就可以顺利拿到RouteMeta了。进入else{}里面，调用了card.setDestination(routeMeta.getDestination())，这个setDestination就是将RouteMeta里面保存的activityClass放入Postcard里面，下面switch代码块可以先不用看，这是实现ARouter中通过依赖注入实现Provider 服务的逻辑，有心研究的同学可以去读一下demo。
好了，prepareCard()方法调用完成后，我们的postcard里面就保存了activityClass，然后switch (postcard.getType()){}会判断postcard的type为ACTIVITY，然后通过ActivityCompat.startActivity启动Activity。到这里，路由跳转的实现已经讲解完毕了。