假设我有网址但不知道它会返回什么。我使用javascript
对该网址执行ajax调用并获取内容。所以我测试它的内容类型并决定如何在我的网页中显示响应。
如果它是json或html或任何其他文本,我会根据需要附加格式化的内容。
现在当内容类型是图像时,我得到图像的响应数据,这不是base64编码的。我当然需要在常规<img>
标记中显示图像。这就是我被卡住的地方。
有没有办法从内容数据中显示图片?
修改
为了说清楚,听到的是我的回应:
"�PNG
IHDR��Nn�tEXtSoftwareAdobe ImageReadyq�e<fiTXtXML:com.adobe.xmp<?xpacket begin="" id="W5M0MpCehiHzreSzNTczkc9d"?> <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="Adobe XMP Core 5.0-c060 61.134777, 2010/02/12-17:32:00 "> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"> <rdf:Description rdf:about="" xmlns:xmpMM="http://ns.adobe.com/xap/1.0/mm/" xmlns:stRef="http://ns.adobe.com/xap/1.0/sType/ResourceRef#" xmlns:xmp="http://ns.adobe.com/xap/1.0/" xmpMM:OriginalDocumentID="xmp.did:8E935AD20E206811822AA1DC23D37A5E" xmpMM:DocumentID="xmp.did:606C15E3DC2311E2A81EB553B5E13CE0" xmpMM:InstanceID="xmp.iid:606C15E2DC2311E2A81EB553B5E13CE0" xmp:CreatorTool="Adobe Photoshop CS5 Macintosh"> <xmpMM:DerivedFrom stRef:instanceID="xmp.iid:0E49679B0D20681192B0DE3AF6794EF0" stRef:documentID="xmp.did:8E935AD20E206811822AA1DC23D37A5E"/> </rdf:Description> </rdf:RDF> </x:xmpmeta> <?xpacket end="r"?>�,��
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答案 0 :(得分:20)
var rawResponse = "�PNG...."; // truncated for example
// convert to Base64
var b64Response = btoa(rawResponse);
// create an image
var outputImg = document.createElement('img');
outputImg.src = 'data:image/png;base64,'+b64Response;
// append it to your page
document.body.appendChild(outputImg);
答案 1 :(得分:2)
接受的答案对我没有用。所以这是我的解决方案:
fetch
下载图片,因此我需要将回复读作blob
:let data; fetch(url).then(response => { response.blob().then(blobResponse => { data = blobResponse; }) });
const urlCreator = window.URL || window.webkitURL; document.getElementById('myImage').src = urlCreator.createObjectURL(data);
答案 2 :(得分:0)
我会使用canvas toDataURL将图像转换为base64,然后将其附加到DOM,如下所示:
var rawResponse = 'PNG'; // This is your response object
var encodedResponse = btoa(rawResponse);
var img = new Image();
var container = document.getElementById('newImg');
img.src = 'data:image/gif;base64,' + encodedResponse;
img.onload = function() {
container.appendChild( img );
};
有关btoa
的更多信息答案 3 :(得分:0)
我们可以获得响应并将其绑定到我的HTML中。
1).ts文件页面:-
imageData : any ;
response => {
var b64Response = btoa(response);
this.imageData = 'data:image/png;base64,' + b64Response;
}
2).html文件页面:
<img [src]="imageData" class="img-thumbnail">
答案 4 :(得分:0)
使用 blob
const response = await fetch(`...`)
const responseBlob = await response.blob()
const img = document.createElement('img')
img.src = URL.createObjectURL(responseBlob)
document.querySelector(`body`).append(img)
解决方案 2
从 blob 中获取 URI.scheme.data。 你可以参考https://stackoverflow.com/a/50463054/9935654
以下示例(案例 2)将向您展示详细信息。
此示例是从 GitHub 的某个存储库中获取图像。
/**
* @param {int} solutionNumber: I provide two solutions both can achieve.
* @param {string} owner
* @param {string} repo
* @param {string} path
* @param {string} branch: branch name or you can use SHA1
* @param {string} token: Used while your repository is private. https://github.com/settings/tokens
*/
async function ShowGithubImg(solutionNumber, owner, repo, path, branch = "master", token = "") {
const response = await fetch(`https://api.github.com/repos/${owner}/${repo}/contents/${path}?ref=${branch}`, {
// method: "GET",
headers: {
accept: 'application/vnd.github.v3.raw',
// authorization: `token ${token}`
}
})
if (!response.ok) {
const errMsg = await response.text()
throw Error(`${response.statusText} (${response.status}) | ${errMsg} `)
}
const responseBlob = await response.blob()
const img = document.createElement('img')
switch (solutionNumber) {
case 1:
img.src = URL.createObjectURL(responseBlob)
break
case 2:
let uriData = ""
blob2bas64 = async (blob) => {
const promise = new Promise((resolve, reject) => {
const reader = new FileReader()
reader.onload = function () { // use promise to wait until onload finished
console.log(this.result) // you can see its media type is: application/vnd.github.v3.raw // https://docs.github.com/en/rest/overview/media-types
uriData = this.result // <--- `this.result` contains a base64 data URI
resolve()
}
reader.readAsDataURL(blob)
})
await promise
}
await blob2bas64(responseBlob)
img.src = `${uriData}`
break
}
document.querySelector(`body`).append(img)
}
for (const solutionNumber of [1, 2]) {
ShowGithubImg(solutionNumber, "CarsonSlovoka", "excel", "app/urls/static/app.ico", "807dd79")
}
@Lostsource 的回答提到了 Uniform Resource Identifier 由于这个问题只询问图像,但有些人有其他格式(图像/jpeg) 其实URI.scheme.data的格式是
<块引用>data:<mediatype>[;base64],<data>
? 你可以在 Uniform Resource Identifier
上看到您只需要知道 mediatype
(common mediatype list)。
例如image/jpeg
data:image/jpeg;base64,<data>