cordova默認(rèn)只能回調(diào)一次，回調(diào)一次后會(huì)被銷毀，再回調(diào)js就收不到回調(diào)

方法：將 CDVPluginResult.keepCallback 設(shè)置為 true ,則不會(huì)銷毀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];

     //將 CDVPluginResult.keepCallback 設(shè)置為 true ,則不會(huì)銷毀callback
    [pluginResult setKeepCallbackAsBool:YES];

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

簡(jiǎn)單解析下多次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];
           // 首先判斷callback是否存在，存在則調(diào)用回調(diào)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);
                }
        
               // 如果這里沒(méi)有設(shè)置keepcallback，則默認(rèn)會(huì)把callbackid從callback數(shù)組中移除，下次就不會(huì)觸發(fā)回調(diào)方法
                if (!keepCallback) {
                    delete cordova.callbacks[callbackId];
                }
       }