base64轉圖片並且下載到本地

這邊是直接下載，要點擊下載的可以把函數綁在觸發事件上：

dataURLtoBlob=(dataurl) => {
    var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
    bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
    while (n--) {
        u8arr[n] = bstr.charCodeAt(n);
    }
    return new Blob([u8arr], { type: mime });
}

//下載圖片到本地
downloadFile=(url, name) => {
    var a = document.createElement('a');
    a.setAttribute('href', url);
    a.setAttribute('download', name);
    a.setAttribute('target', '_blank');
    let clickEvent = document.createEvent('MouseEvents');
    clickEvent.initEvent('click', true, true); //模擬點擊
    a.dispatchEvent(clickEvent);
}

downloadFileByBase64=(base64, name) => {
    var myBlob = this.dataURLtoBlob(base64);
    var myUrl = URL.createObjectURL(myBlob);
    this.downloadFile(myUrl, name); //base64：傳入base64  name:為下載圖片名字，自定義
}

.......

this.downloadFileByBase64(base64, name) //調用