image-tools.js 4.1 KB

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  1. // 图像转换工具,可用于图像和base64的转换
  2. // https://ext.dcloud.net.cn/plugin?id=123
  3. const getLocalFilePath = (path) => {
  4. if (
  5. path.indexOf('_www') === 0 ||
  6. path.indexOf('_doc') === 0 ||
  7. path.indexOf('_documents') === 0 ||
  8. path.indexOf('_downloads') === 0
  9. ) return path
  10. if (path.indexOf('/storage/emulated/0/') === 0) return path
  11. if (path.indexOf('/storage/sdcard0/') === 0) return path
  12. if (path.indexOf('/var/mobile/') === 0) return path
  13. if (path.indexOf('file://') === 0) return path
  14. if (path.indexOf('/') === 0) {
  15. // ios 无法获取本地路径
  16. let localFilePath = plus.os.name === 'iOS' ? path : plus.io.convertLocalFileSystemURL(path)
  17. if (localFilePath !== path) {
  18. return localFilePath
  19. } else {
  20. path = path.substring(1)
  21. }
  22. }
  23. return '_www/' + path
  24. }
  25. export const pathToBase64 = (path) => {
  26. return new Promise((resolve, reject) => {
  27. if (typeof window === 'object' && 'document' in window) {
  28. if (typeof FileReader === 'function') {
  29. let xhr = new XMLHttpRequest()
  30. xhr.open('GET', path, true)
  31. xhr.responseType = 'blob'
  32. xhr.onload = function() {
  33. if (this.status === 200) {
  34. let fileReader = new FileReader()
  35. fileReader.onload = function(e) {
  36. resolve(e.target.result)
  37. }
  38. fileReader.onerror = reject
  39. fileReader.readAsDataURL(this.response)
  40. }
  41. }
  42. xhr.onerror = reject
  43. xhr.send()
  44. return
  45. }
  46. let canvas = document.createElement('canvas')
  47. let c2x = canvas.getContext('2d')
  48. let img = new Image
  49. img.onload = function() {
  50. canvas.width = img.width
  51. canvas.height = img.height
  52. c2x.drawImage(img, 0, 0)
  53. resolve(canvas.toDataURL())
  54. canvas.height = canvas.width = 0
  55. }
  56. img.onerror = reject
  57. img.src = path
  58. return
  59. }
  60. if (typeof plus === 'object') {
  61. let tempPath = getLocalFilePath(path)
  62. plus.io.resolveLocalFileSystemURL(tempPath, (entry) => {
  63. entry.file((file) => {
  64. let fileReader = new plus.io.FileReader()
  65. fileReader.onload = function(data) {
  66. resolve(data.target.result)
  67. }
  68. fileReader.onerror = function(error) {
  69. console.log(error)
  70. reject(error)
  71. }
  72. fileReader.readAsDataURL(file)
  73. }, (error) => {
  74. reject(error)
  75. })
  76. }, (error) => {
  77. reject(error)
  78. })
  79. return
  80. }
  81. if (typeof wx === 'object' && wx.canIUse('getFileSystemManager')) {
  82. wx.getFileSystemManager().readFile({
  83. filePath: path,
  84. encoding: 'base64',
  85. success: (res) => {
  86. resolve('data:image/png;base64,' + res.data)
  87. },
  88. fail: (error) => {
  89. reject(error)
  90. }
  91. })
  92. return
  93. }
  94. reject(new Error('not support'))
  95. })
  96. }
  97. export const base64ToPath = (base64) => {
  98. return new Promise((resolve, reject) => {
  99. if (typeof window === 'object' && 'document' in window) {
  100. base64 = base64.split(',')
  101. let type = base64[0].match(/:(.*?);/)[1]
  102. let str = atob(base64[1])
  103. let n = str.length
  104. let array = new Uint8Array(n)
  105. while (n--) {
  106. array[n] = str.charCodeAt(n)
  107. }
  108. return resolve((window.URL || window.webkitURL).createObjectURL(new Blob([array], {
  109. type: type
  110. })))
  111. }
  112. let extName = base64.match(/data\:\S+\/(\S+);/)
  113. if (extName) {
  114. extName = extName[1]
  115. } else {
  116. reject(new Error('base64 error'))
  117. }
  118. let fileName = Date.now() + '.' + extName
  119. if (typeof plus === 'object') {
  120. let bitmap = new plus.nativeObj.Bitmap('bitmap' + Date.now())
  121. bitmap.loadBase64Data(base64, () => {
  122. let filePath = '_doc/uniapp_temp/' + fileName
  123. bitmap.save(filePath, {}, () => {
  124. bitmap.clear()
  125. resolve(filePath)
  126. }, (error) => {
  127. bitmap.clear()
  128. reject(error)
  129. })
  130. }, (error) => {
  131. bitmap.clear()
  132. reject(error)
  133. })
  134. return
  135. }
  136. if (typeof wx === 'object' && wx.canIUse('getFileSystemManager')) {
  137. let filePath = wx.env.USER_DATA_PATH + '/' + fileName
  138. wx.getFileSystemManager().writeFile({
  139. filePath: filePath,
  140. data: base64.replace(/^data:\S+\/\S+;base64,/, ''),
  141. encoding: 'base64',
  142. success: () => {
  143. resolve(filePath)
  144. },
  145. fail: (error) => {
  146. reject(error)
  147. }
  148. })
  149. return
  150. }
  151. reject(new Error('not support'))
  152. })
  153. }