1. Introducing JSBridge
JSBridge mainly provides JavaScript with an interface to call Native functions, so that the front-end part in hybrid development can easily use Native functions (such as: address book, Bluetooth).
Moreover, the function of JSBridge is not as simple and broad as calling Native functions. In fact, JSBridge, just like the Bridge in its name, is a bridge between Native and non-Native. Its core is to build a channel for message communication between Native and non-Native, and this communication channel is bidirectional.
2. JS calls Android native methods
1. Add Javascript interface: assign the interface of related methods of Android to a special js object, and then assign it to the window object, such as PosObj in the following code block project
private void initJs() {
//增加Javascript的接口
webView.addJavascriptInterface(new MyJSI(this), "PosObj");
}
2. The method of creating a total js call must be annotated with @JavascriptInterface
@JavascriptInterface
public String invokeFun(String funName, String json) {
}
//通用
@JavascriptInterface
public void close() {
//js调用完以后的逻辑
}
3. Example: encapsulating the method of obtaining the version number
public String getVersionName(Context context) {
PackageManager packageManager = context.getPackageManager();
// getPackageName()是你当前类的包名，0代表是获取版本信息
PackageInfo packInfo = null;
String version = "";
try {
packInfo = packageManager.getPackageInfo(context.getPackageName(), 0);
version = packInfo.versionName;
} catch (PackageManager.NameNotFoundException e) {
e.printStackTrace();
}
return version;
}
4. js calls the Android method ()//put the handleAndroid method where it needs to be called
function handleAndroid(){
// 由于对象映射，所以调用PosObj对象等于调用Android映射的对象
//getVersionName是Android的方法
window.PosObj.invokeFun('getVersionName', '')
}