小程序base64格式转成png图片格式

const fsm = wx.getFileSystemManager();
const FILE_BASE_NAME = ‘tmp_base64src‘;

function base64src(base64data, cb) {
const qs = /data:image\/(\w+);base64,(.*)/.exec(base64data) || [];
const [, format, bodyData] = /data:image\/(\w+);base64,(.*)/.exec(base64data) || [];
console.log(qs)
if (!format) {
return (new Error(‘ERROR_BASE64SRC_PARSE‘));
}
const filePath = `${wx.env.USER_DATA_PATH}/${FILE_BASE_NAME}.${format}`;
const buffer = wx.base64ToArrayBuffer(bodyData);
console.log(‘filePath‘,filePath, ‘buffer‘, buffer)
fsm.writeFile({
filePath,
data: buffer,
encoding: ‘binary‘,
success() {
cb(filePath);
},
fail() {
return (new Error(‘ERROR_BASE64SRC_WRITE‘));
},
});
};
export { base64src };