vue中v-if和v-show使用区别源码分析_vue.js_

new Vue({ el: "#app", data() { return { isShow: false, }; }, methods: { changeStatus() { this.isShow = !this.isShow; } }, template: `
切换
显示
` }); 

`with(this){ return _c('div',[_c('button',{on:{"click":changeStatus}},[_v("切换")]),(isShow)?_c('div',[_v("显示")]):_e()]) }` 

else if (isTrue(vnode.isComment)) { vnode.elm = nodeOps.createComment(vnode.text); insert(parentElm, vnode.elm, refElm); } 

new Vue({ el: "#app", data() { return { isShow: false, }; }, methods: { changeStatus() { this.isShow = !this.isShow; } }, template: `
切换
显示
` }); 

`with(this){ return _c('div',[_c('button',{on:{"click":changeStatus}},[_v("切换")]),_c('div',{directives:[{name:"show",rawName:"v-show",value:(isShow),expression:"isShow"}]},[_v("显示")])]) }` 

data: { directives: { expression: "isShow", name: "show", rawName: "v-show", value: false, } } 

 { createChildren(vnode, children, insertedVnodeQueue); if (isDef(data)) { invokeCreateHooks(vnode, insertedVnodeQueue); } insert(parentElm, vnode.elm, refElm); } 

function invokeCreateHooks (vnode, insertedVnodeQueue) { for (let i = 0; i < cbs.create.length; ++i) { cbs.create[i](emptyNode, vnode) } i = vnode.data.hook // Reuse variable if (isDef(i)) { if (isDef(i.create)) i.create(emptyNode, vnode) if (isDef(i.insert)) insertedVnodeQueue.push(vnode) } } 

function updateDirectives (oldVnode: VNodeWithData, vnode: VNodeWithData) { if (oldVnode.data.directives || vnode.data.directives) { _update(oldVnode, vnode) } } function _update (oldVnode, vnode) { const isCreate = oldVnode === emptyNode const isDestroy = vnode === emptyNode const oldDirs = normalizeDirectives(oldVnode.data.directives, oldVnode.context) const newDirs = normalizeDirectives(vnode.data.directives, vnode.context) const dirsWithInsert = [] const dirsWithPostpatch = [] let key, oldDir, dir for (key in newDirs) { oldDir = oldDirs[key] dir = newDirs[key] if (!oldDir) { // new directive, bind callHook(dir, 'bind', vnode, oldVnode) if (dir.def && dir.def.inserted) { dirsWithInsert.push(dir) } } else { // existing directive, update dir.oldValue = oldDir.value dir.oldArg = oldDir.arg callHook(dir, 'update', vnode, oldVnode) if (dir.def && dir.def.componentUpdated) { dirsWithPostpatch.push(dir) } } } // ... } 

function normalizeDirectives$1 ( dirs, vm ) { var res = Object.create(null); if (!dirs) { // $flow-disable-line return res } var i, dir; for (i = 0; i < dirs.length; i++) { dir = dirs[i]; if (!dir.modifiers) { // $flow-disable-line dir.modifiers = emptyModifiers; } res[getRawDirName(dir)] = dir; dir.def = resolveAsset(vm.$options, 'directives', dir.name, true); } // $flow-disable-line return res } /** * Resolve an asset. * This function is used because child instances need access * to assets defined in its ancestor chain. */ function resolveAsset ( options, type, id, warnMissing ) { /* istanbul ignore if */ if (typeof id !== 'string') { return } var assets = options[type]; // check local registration variations first if (hasOwn(assets, id)) { return assets[id] } var camelizedId = camelize(id); if (hasOwn(assets, camelizedId)) { return assets[camelizedId] } var PascalCaseId = capitalize(camelizedId); if (hasOwn(assets, PascalCaseId)) { return assets[PascalCaseId] } // fallback to prototype chain var res = assets[id] || assets[camelizedId] || assets[PascalCaseId]; if (process.env.NODE_ENV !== 'production' && warnMissing && !res) { warn( 'Failed to resolve ' + type.slice(0, -1) + ': ' + id, options ); } return res } 

export default { bind (el: any, { value }: VNodeDirective, vnode: VNodeWithData) { vnode = locateNode(vnode) const transition = vnode.data && vnode.data.transition const originalDisplay = el.__vOriginalDisplay = el.style.display === 'none' ? '' : el.style.display if (value && transition) { vnode.data.show = true enter(vnode, () => { el.style.display = originalDisplay }) } else { el.style.display = value ? originalDisplay : 'none' } }, // 这里还有unbind和update方法 } 

function callHook (dir, hook, vnode, oldVnode, isDestroy) { const fn = dir.def && dir.def[hook] if (fn) { try { fn(vnode.elm, dir, vnode, oldVnode, isDestroy) } catch (e) { handleError(e, vnode.context, `directive ${dir.name} ${hook} hook`) } } }