iOS Cordova 多次回调callback

cordova默认只能回调一次，回调一次后会被销毁，再回调js就收不到回调

方法：将 CDVPluginResult.keepCallback 设置为 true ,则不会销毁callback

   CDVPluginResult* pluginResult;
    NSMutableDictionary* successDictionary = [NSMutableDictionary dictionaryWithCapacity:3];
    [successDictionary setObject:[NSString stringWithFormat:@"%f",_playerView.currentTime] forKey:@"position"];
    [successDictionary setObject:[NSString stringWithFormat:@"%f",_playerView.videoAllTime] forKey:@"duration"];
    [successDictionary setObject:[NSString stringWithFormat:@"%@",_videoid] forKey:@"videoid"];
    pluginResult = [CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsDictionary:successDictionary];

     //将 CDVPluginResult.keepCallback 设置为 true ,则不会销毁callback
    [pluginResult setKeepCallbackAsBool:YES];

    [self.plugin.commandDelegate sendPluginResult:pluginResult callbackId:self.callback];

简单解析下多次callback原理

 cordova.js 文件中：
// 接受原生callback方法
 callbackFromNative: function(callbackId, isSuccess, status, args, keepCallback) {
        try {
            var callback = cordova.callbacks[callbackId];
           // 首先判断callback是否存在，存在则调用回调方法
            if (callback) {
                if (isSuccess && status == cordova.callbackStatus.OK) {
                    callback.success && callback.success.apply(null, args);
                } else if (!isSuccess) {
                    callback.fail && callback.fail.apply(null, args);
                }
        
               // 如果这里没有设置keepcallback，则默认会把callbackid从callback数组中移除，下次就不会触发回调方法
                if (!keepCallback) {
                    delete cordova.callbacks[callbackId];
                }
       }