Question

js 怎么实现image的二进制流

Answer 1

var convertImgDataToBlob = function (base64Data) {
                var format = "image/jpeg";
                var base64 = base64Data;
                var code = window.atob(base64.split(",")[1]);
                var aBuffer = new window.ArrayBuffer(code.length);
                var uBuffer = new window.Uint8Array(aBuffer);
                for(var i = 0; i < code.length; i++){
                    uBuffer[i] = code.charCodeAt(i) & 0xff ;
                }
                console.info([aBuffer]);
                console.info(uBuffer);
                console.info(uBuffer.buffer);
                console.info(uBuffer.buffer==aBuffer); //true

                var blob=null;
                try{
                    blob = new Blob([uBuffer], {type : format});
                }
                catch(e){
                    window.BlobBuilder = window.BlobBuilder ||
                    window.WebKitBlobBuilder ||
                    window.MozBlobBuilder ||
                    window.MSBlobBuilder;
                    if(e.name == 'TypeError' && window.BlobBuilder){
                        var bb = new window.BlobBuilder();
                        bb.append(uBuffer.buffer);
                        blob = bb.getBlob("image/jpeg");

                    }
                    else if(e.name == "InvalidStateError"){
                        blob = new Blob([aBuffer], {type : format});
                    }
                    else{

                    }
                }
                alert(blob.size);
                return blob;
               
            };

Answer 2

canvas或者buffer