Axios 使用 onDownloadProgress 配置响应 GET 请求，返回 progressEvent.total: 0

Question

我正在尝试在使用 axios 创建的获取请求期间创建进度加载指示器，但 progressEvent.total 始终为 0。用axios提供的onDownloadProgress(progressEvent)还有其他方法可以准确计算吗？这是对象：

progress

bubbles: false
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cancelBubble: false
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cancelable: false
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composed: false
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currentTarget: null
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defaultPrevented: false
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eventPhase: 0
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explicitOriginalTarget: XMLHttpRequest { readyState: 4, timeout: 0, withCredentials: false, … }
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isTrusted: true
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lengthComputable: false
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loaded: 9924
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originalTarget: XMLHttpRequest { readyState: 4, timeout: 0, withCredentials: false, … }
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returnValue: true
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srcElement: XMLHttpRequest { readyState: 4, timeout: 0, withCredentials: false, … }
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target: XMLHttpRequest { readyState: 4, timeout: 0, withCredentials: false, … }
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timeStamp: 23792
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total: 0
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type: "progress"
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<get isTrusted()>: function isTrusted()
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<prototype>: ProgressEventPrototype { lengthComputable: Getter, loaded: Getter, total: Getter, … }