type
property of a
Blob
object returns the
MIME 类型
of the file.
var mimetype = blob.type
A
DOMString
containing the file's MIME type, or an empty string if the type could not be determined.
This example asks the user to select a number of files, then checks each file to make sure it's one of a given set of image file types.
var i, fileInput, files, allowedFileTypes;
// fileInput is a HTMLInputElement: <input type="file" multiple id="myfileinput">
fileInput = document.getElementById("myfileinput");
// files is a FileList object (simliar to NodeList)
files = fileInput.files;
// our application only allows GIF, PNG, and JPEG images
allowedFileTypes = ["image/png", "image/jpeg", "image/gif"];
for (i = 0; i < files.length; i++) {
// Test if file.type is an allowed file type.
if (allowedFileTypes.indexOf(files[i].type) > -1) {
// file type matched is one of allowed file types. Do something here.
}
});
| 规范 | 状态 | 注释 |
|---|---|---|
|
文件 API
The definition of 'Blob.type' in that specification. |
工作草案 | 初始定义。 |
| 桌面 | 移动 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
type
|
Chrome 5 | Edge 12 | Firefox 4 | IE 10 | Opera 11 | Safari 5.1 | WebView Android 不支持 No | Chrome Android 18 | Firefox Android 不支持 No | Opera Android 不支持 No | Safari iOS 不支持 No | Samsung Internet Android 1.0 |
完整支持
不支持