update 恢复文件预览权限验证,新增图片组件,从接口读取文件流

Web/src/util/file/index.js

@@ -0,0 +1,85 @@
+const _getFileTypeByBase64 = (base64) => {
+    let arr = base64.split(','),
+        fileType = arr[0].match(/:(.*?);/)[1]
+    return fileType
+}
+
+/**
+ * ArrayBuffer转Base64
+ * @param {*} arrayBuffer 
+ * @returns 
+ */
+export const ArrayBufferToBase64 = async (arrayBuffer) => {
+    const blob = ArrayBufferToBlob(arrayBuffer)
+    const base64 = await BlobToBase64(blob)
+    return base64
+}
+
+/**
+ * ArrayBuffer转Blob
+ * @param {*} arrayBuffer 
+ * @returns 
+ */
+export const ArrayBufferToBlob = (arrayBuffer) => {
+    return new Blob([arrayBuffer])
+}
+
+/**
+ * Base64转Blob
+ * @param {*} base64 
+ * @returns 
+ */
+export const Base64ToBlob = (base64) => {
+    let arr = base64.split(','),
+        fileType = _getFileTypeByBase64(base64),
+        bstr = atob(arr[1]),
+        n = bstr.length,
+        u8arr = new Uint8Array(n)
+
+    while (n--) {
+        u8arr[n] = bstr.charCodeAt(n)
+    }
+    return new Blob([u8arr], { type: fileType })
+}
+
+/**
+ * Blob转文件
+ * @param {*} blob 
+ * @param {*} fileName 
+ * @param {*} fileType 
+ * @returns 
+ */
+export const BlobToFile = (blob, fileName, fileType) => {
+    blob.lastModifiedDate = new Date()
+    blob.name = fileName
+    const file = new File([blob], fileName, { type: fileType })
+    return file
+}
+
+/**
+ * Base64转文件
+ * @param {*} base64 
+ * @param {*} fileName 
+ * @returns 
+ */
+export const Base64ToFile = (base64, fileName) => {
+    const blob = Base64ToBlob(base64)
+    const fileType = _getFileTypeByBase64(base64)
+    const file = BlobToFile(blob, fileName, fileType)
+    return file
+}
+
+/**
+ * Blob转Base64
+ * @param {*} blob 
+ * @returns 
+ */
+export const BlobToBase64 = async (blob) => {
+    return new Promise(resolve => {
+        const reader = new FileReader()
+        reader.readAsDataURL(blob)
+        reader.onload = (e) => {
+            resolve(e.target.result)
+        }
+    })
+}