Question

我成功地创建了目录，如果有必要，我想在我的设备上的Android文件系统中创建一个Moto X 1st gen。我成功保存了纯文本文件，但无法保存jpg文件。我有一个base64编码的图像字符串，它在我的img标签中显示src =“data：image / jpeg; base64，/ 9j / 4AAQSkZJRgABAQAAAQ ...”。在下面的第17行，我写了一个文件，其中“data：image / jpeg; base64”替换为“”（空字符串）。在写入文件之前是否有转换为二进制或我需要做的事情？我在notepad ++中打开了下面用代码片段编写的文件，我看到了很长的base64编码字符串。任何帮助将不胜感激。抱歉，我无法提供完整的代码，因为它非常大。我知道我的代码可以写文件，但是图像文件没有正确写入。谢谢！

var wpt = '01';
imageName = wpt + imageName;
var geoJSON = '{"type":"FeatureCollection","crs":{"type":"name","properties":{"name":"urn:ogc:def:crs:EPSG::3857"}},"features":[{"type":"Feature","properties":{"TYPE":"WAYPOINT","IDENT":"null","LAT":' + latitude + ',"LONG":' + longitude + ',"Y_PROJ":null,"X_PROJ":null,"COMMENT":"' + createDate + ' ' + createTime + '","DISPLAY":"null","SYMBOL":"null","UNUSED1":"null","DIST":null,"PROX_INDEX":"null","COLOR":"null","ALTITUDE":null,"DEPTH":null,"TEMP":null,"TIME":"null","WPT_CLASS":"null","SUB_CLASS":null,"ATTRIB":"null","LINK":null,"STATE":null,"COUNTRY":null,"CITY":null,"ADDRESS":null,"FACILITY":null,"CROSSROAD":null,"UNUSED2":"null","ETE":"null","DTYPE":"null","MODEL":"SUNSAIL","FILENAME":"' + description + '","LTIME":"null","WPT":"' + wpt + '"},"geometry":{"type":"Point","coordinates":[' + coordinates + ']}}]}';
root.getFile(gisPath + '/' + gisName, { create: true, exclusive: false}, function(fileEntry) {
    fileEntry.createWriter(function(writer) {
        writer.onwriteend = function(evt) {
            root.getFile(photoPath + '/' + imageName, { create: true, exclusive: false}, function(fileEntry) {
                fileEntry.createWriter(function(writer) {
                    writer.onwriteend = function(evt) {
                        if (i == (numImages - 1)) {
                            alert('Waypoint data and images saved succesfully for later upload.');
                            clearCache();
                            clearNew();
                            $('.uploader').remove();
                        }
                    }
                    writer.write(img.src.replace(/data:image\/jpeg;base64,/, ''));
                }, function(evt) {
                    alert('Error code: ' + evt.target.error.code + '\n' + 'Error message: ' + evt.target.error.message);
                });
            }, function(evt) {
                alert('Error code: ' + evt.target.error.code + '\n' + 'Error message: ' + evt.target.error.message);
            });
        }
        writer.write(geoJSON);
    }, function(evt) {
        alert('Error code: ' + evt.target.error.code + '\n' + 'Error message: ' + evt.target.error.message);
    });
}, function (evt) {
    alert('Error code: ' + evt.target.error.code + '\n' + 'Error message: ' + evt.target.error.message);
});

Answer 1

我用

替换了第17行

writer.write(b64toBlob(img.src.replace(/data:image\/jpeg;base64,/, ''), 'image/jpg', 512));

这是我的b64toBlob功能

function b64toBlob(b64Data, contentType, sliceSize) {
    contentType = contentType || '';
    sliceSize = sliceSize || 512;
    var byteCharacters = atob(b64Data);
    var byteArrays = [];
    for (var offset = 0; offset < byteCharacters.length; offset += sliceSize) {
        var slice = byteCharacters.slice(offset, offset + sliceSize);
        var byteNumbers = new Array(slice.length);
        for (var i = 0; i < slice.length; i++) {
            byteNumbers[i] = slice.charCodeAt(i);
        }
        var byteArray = new Uint8Array(byteNumbers);
        byteArrays.push(byteArray);
    }
    var blob = new Blob(byteArrays, {type: contentType});
    return blob;
}

这适用于将jpg图像保存到本地Android文件系统。

Cordova-Android-Camera：如何将base64编码的jpg保存到Android文件系统

1 个答案: