PhoneGap FileReader / readAsDataURL不触发回调 [英] PhoneGap FileReader/readAsDataURL Not Triggering Callbacks

问题描述

我使用PhoneGap Build建立iOS v7.1 +应用程式，并使用 weinre 来调试。我使用媒体捕获插件和文件API捕获视频，试图获得其base64表示。我可以得到录像机打开，拍摄视频，并返回文件路径。然后使用 resolveLocalFileSystemURL（）获取 readAsDataURL（）所需的文件对象。问题是 FileReader 从不调用 onloadend 回调。

I am using PhoneGap Build to build an iOS v7.1+ application and using weinre to debug. I am using the media-capture plugin and file API to capture a video in an attempt get its base64 representation. I can get the video recorder to open, take a video, and return the file path. I then use resolveLocalFileSystemURL() to get a file object which readAsDataURL() requires. The problem is FileReader is never calling the onloadend callback.

我一整天都在偷窥。把 console.log（）放在我想到的地方。我查看了以确保iOS版本受支持。每个变量是我所期望的，但回调只是不被调用。我也试过设置所有其他回调，但没有一个被调用。我试着用 readAsText（）替换 readAsDataURL（），但我还是得到bupkis。我已经尝试等待五分钟，因为我认为异步调用可能需要一些，但仍然没有什么。

I have been poking around all day. Putting console.log()'s everywhere I could think of. I checked to make sure the iOS version is supported. Every variable is what I expect yet the callback is simply not being called. I have also tried setting up all the other callbacks but none of them ever get called, either. I have tried replacing readAsDataURL() with readAsText() but I still get bupkis. I have tried waiting up to five minutes since I figured an asynchronous call may take a bit but still nothing.

下面是我的代码。下面是控制台输出。

Below is my code. Below that is the console output.

var elements = new Object();
elements["video"] = $("#window_incident_create > .video > source")[0];

navigator.device.capture.captureVideo(
    function(files) {
        for ( var i in files ) {
            var file = files[i];

            var name = file.name;
            var path = file.fullPath;
            if ( path.indexOf("/private") === 0 )
                path = "file://" + path.substr(8);
            else
                path = "file://" + path;
            var type = file.type;
            var lastModifiedDate = file.lastModifiedDate;
            var size = file.size;

            var reader = new FileReader();
            reader.onloadend = function(event) {
                console.log(3);
                elements["video"].type = type;
                elements["video"].src = "data:" + type + ";base64," + event.target.result;
                console.log(4);
            };

            window.resolveLocalFileSystemURL(
                path,
                function(entry) {
                    console.log(1, entry.nativeURL);
                    reader.readAsDataURL(entry);
                    console.log(2);
                },
                function(error) {
                    console.log("0-0", error);
                }
            );
        }
    },
    function(error) {
        console.log("0-1", error);
    },
    {
        limit:  1
    }
);

1file：/// var / mobile / Applications / AB239984 -FB9F-43C0-B699-3596AC8A43A8 / tmp / capture / capturedvideo.MOV

1 "file:///var/mobile/Applications/AB239984-FB9F-43C0-B699-3596AC8A43A8/tmp/capture/capturedvideo.MOV"

2

推荐答案

重组你的代码。将读取器初始化和 onloadend 中的回调放在 resolveLocalFileSystemURL 回调。

Reorganize your code a bit. Put the reader initialisation and onloadend callback inside the resolveLocalFileSystemURL success callback.

这样：

var elements = new Object();
elements["video"] = $("#window_incident_create > .video > source")[0];

navigator.device.capture.captureVideo(
    function(files) {
        for ( var i in files ) {
            var file = files[i];

            var name = file.name;
            var path = file.fullPath;
            if ( path.indexOf("/private") === 0 )
                path = "file://" + path.substr(8);
            else
                path = "file://" + path;
            var type = file.type;
            var lastModifiedDate = file.lastModifiedDate;
            var size = file.size;

            window.resolveLocalFileSystemURL(
                path,
                function(entry) {
                    console.log(1, entry.nativeURL);
                    var reader = new FileReader();
                    reader.onloadend = function(event) {
                        console.log(3);
                        elements["video"].type = type;
                        elements["video"].src = "data:" + type + ";base64," + event.target.result;
                        console.log(4);
                    };
                    reader.readAsDataURL(entry);
                    console.log(2);
                },
                function(error) {
                    console.log("0-0", error);
                }
            );
        }
    },
    function(error) {
        console.log("0-1", error);
    },
    {
        limit:  1
    }
);

这篇关于PhoneGap FileReader / readAsDataURL不触发回调的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！