如何使用cordova/phonegap从Java应用程序/插件向javascript发送数据或消息
我想我在这里错过了一些东西.我习惯于将数据从javascript发送到Java,然后通过调用来执行和使用callbackContext方法返回.
I think I'm missing something here. I'm used to sending data from javascript to java and back with calls to execute and back with the callbackContext methods.
但是,如果在某些时候,我有一个正在运行的线程需要定期向javascript发送数据,那我该怎么办呢? (这假设此任务正在运行,并且没有被javascript操作触发,因此没有callbackContext可用)
But if at some points, lets say I have a running thread that needs to send data to the javascript at regular intervals, how should I do that then ? (This assumes that this task is running and has not been triggered by a javascript action, thus no callbackContext is available)
您始终可以通过Java执行javascript,具体操作如下:
You can always execute javascript from java doing this:
String js = "alert('test')";
webView.loadUrlNow("javascript:" + js);
或者您可以初始化插件并保持回调执行此操作
Or you can init the plugin and keep the callback doing this
PluginResult pgRes = new PluginResult(PluginResult.Status.OK, "message");
pgRes.setKeepCallback(true);
callbackContext.sendPluginResult(pgRes);
添加了Sephy提供的示例
Added example provided by Sephy
private String myCbkId;
// Store callbackId from a call to execute
@Override public boolean execute(String action, JSONArray arr, CallbackContext cbkCtx) throws JSONException {
myCbkId = cbkCtx.getCallbackId();
JSONObject data = arr.getJSONObject(0);
String ack = data.getString("data"); // You can acknowledge to the callback for instance and keep it alive
Log.d(TAG, "ack".equals(ack) ? "ack !" : "not ack !");
// These lines can be reused anywhere in your app to send data to the javascript
PluginResult result = new PluginResult(PluginResult.Status.OK, ack);
result.setKeepCallback(true);//This is the important part that allows executing the callback more than once, change to false if you want the callbacks to stop firing
this.webView.sendPluginResult(result, this.myCbkId);
return true;
}