尝试在iOS Safari 8中存储blob会引发DataCloneError-Java 学习之路

当我尝试存储blob（通过 XMLHttpRequest GET 请求检索时，iOS 8.4上的Safari会抛出错误：

DataCloneError: DOM IDBDatabase Exception 25: The data being stored could
not be cloned by the internal structured cloning algorithm

这发生在我的代码和这个例子中：http://robnyman.github.io/html5demos/indexeddb/

这是导致我的代码（和上面的示例）失败的行：

//This throws the error
var put = transaction.objectStore("elephants").put(blob, "image");

有没有解决这个问题？ blob是否需要首先进行base64编码（就像你必须使用WebSQL一样）？

My CODE （适用于桌面Chrome / Firefox和Android上的Chrome / Firefox）：

var xhr = new XMLHttpRequest();
var blob;

//Get the Video
xhr.open( "GET", "test.mp4", true );

//Set as blob
xhr.responseType = "blob";

//Listen for blob
xhr.addEventListener("load", function () {
        if (xhr.status === 200) {
            blob = xhr.response;

            //Start transaction
            var transaction = db.transaction(["Videos"], "readwrite");

            //IT FAILS HERE
            var put = transaction.objectStore("Videos").put(blob, "savedvideo");

        }
        else {
            console.log("ERROR: Unable to download video." );
        }
}, false);

xhr.send();

1 回答

由于一些奇怪的原因（它是_2877141_的WebSQL，你在iOS Safari 8上存储了一个BLOB在IndexedDB中 . 你必须将它转换为base64然后它将存储而没有错误 . （我再说一遍，这是一个bug）

所以，将代码更改为：

Change response type

xhr.responseType = "arraybuffer";

Storing in database after retrieving from XMLHttpRequest

//We'll make an array of unsigned ints to convert
var uInt8Array = new Uint8Array(xhr.response);
var i = uInt8Array.length;
var binaryString = new Array(i);
while (i--)
{
    //Convert each to character
    binaryString[i] = String.fromCharCode(uInt8Array[i]);
}

//Make into a string
var data = binaryString.join('');

//Use built in btoa to make it a base64 encoded string
var base64 = window.btoa(data);

//Now we can save it
var transaction = db.transaction(["Videos"], "readwrite");
var put = transaction.objectStore("Videos").put(base64, "savedvideo");

After retrieving form the IndexedDB, convert it back:

//Convert back to bytes
var data = atob( event.target.result );

//Make back into unsigned array
var asArray = new Uint8Array(data.length);

for( var i = 0, len = data.length; i < len; ++i ) 
{
    //Get back as int
    asArray[i] = data.charCodeAt(i);    
}

//Make into a blob of proper type
var blob = new Blob( [ asArray.buffer ], {type: "video/mp4"} );

//Make into object url for video source
var videoURL = URL.createObjectURL(blob);

回复于 2024-04-28T18:25:24+08:00

尝试在iOS Safari 8中存储blob会引发DataCloneError

1 回答

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