diff --git a/src/components/QrItem.js b/src/components/QrItem.js
index 4f1c8c4..944117a 100644
--- a/src/components/QrItem.js
+++ b/src/components/QrItem.js
@@ -6,18 +6,17 @@ function calClassName(props) {
     return 'Qr-item';
 }
 
-class QrItem extends React.Component {
+export default class QrItem extends React.Component {
 
     constructor(props) {
         super(props);
-        this.handleClick = this.handleClick.bind(this);
     }
 
     componentDidMount() {
         this.forceUpdate()
     }
 
-    handleClick(e) {
+    handleClick = (e) => {
         this.props.onSelected(this.props.index);
     }
 
@@ -40,5 +39,3 @@ class QrItem extends React.Component {
         );
     }
 }
-
-export default QrItem;
diff --git a/src/components/QrRendererBase.js b/src/components/QrRendererBase.js
index 0b3ba49..34ab950 100644
--- a/src/components/QrRendererBase.js
+++ b/src/components/QrRendererBase.js
@@ -70,7 +70,7 @@ function listPoint(props) {
     return pointList;
 }
 
-class QrRendererBase extends React.Component {
+export default class QrRendererBase extends React.Component {
     constructor(props) {
         super(props);
         if (this.props.setParamInfo) {
@@ -111,4 +111,3 @@ class QrRendererBase extends React.Component {
     }
 }
 
-export default QrRendererBase
diff --git a/src/components/QrRendererBlank.js b/src/components/QrRendererBlank.js
index 39b787d..be3c819 100644
--- a/src/components/QrRendererBlank.js
+++ b/src/components/QrRendererBlank.js
@@ -2,10 +2,9 @@ import React from "react";
 import './Qrcode.css'
 import {defaultRenderer} from "../utils/util";
 
-class QrRendererBlank extends React.Component {
+export default class QrRendererBlank extends React.Component {
     render() {
         return defaultRenderer(this.props.qrcode);
     }
 }
 
-export default QrRendererBlank
diff --git a/src/components/QrRendererDSJ.js b/src/components/QrRendererDSJ.js
index 3de682c..c3f2259 100644
--- a/src/components/QrRendererDSJ.js
+++ b/src/components/QrRendererDSJ.js
@@ -159,7 +159,7 @@ function listPoint(props) {
     return pointList;
 }
 
-class QrRendererDSJ extends React.Component {
+export default class QrRendererDSJ extends React.Component {
     constructor(props) {
         super(props);
         if (this.props.setParamInfo) {
@@ -190,4 +190,3 @@ class QrRendererDSJ extends React.Component {
     }
 }
 
-export default QrRendererDSJ
diff --git a/src/components/QrRendererRandRect.js b/src/components/QrRendererRandRect.js
index 5913c87..75dfb1d 100644
--- a/src/components/QrRendererRandRect.js
+++ b/src/components/QrRendererRandRect.js
@@ -38,10 +38,9 @@ function listPoint(props) {
     return pointList;
 }
 
-class QrRendererRandRect extends React.Component {
+export default class QrRendererRandRect extends React.Component {
     render() {
         return defaultRenderer(this.props.qrcode, listPoint(this.props));
     }
 }
 
-export default QrRendererRandRect
diff --git a/src/components/QrRendererRandRound.js b/src/components/QrRendererRandRound.js
index d353162..109122f 100644
--- a/src/components/QrRendererRandRound.js
+++ b/src/components/QrRendererRandRound.js
@@ -70,7 +70,7 @@ function listPoint(props) {
     return pointList;
 }
 
-class QrRendererRandRound extends React.Component {
+export default class QrRendererRandRound extends React.Component {
     constructor(props) {
         super(props);
         if (this.props.setParamInfo) {
@@ -111,4 +111,3 @@ class QrRendererRandRound extends React.Component {
     }
 }
 
-export default QrRendererRandRound
diff --git a/src/components/QrRendererRound.js b/src/components/QrRendererRound.js
index a5555cb..cf1762b 100644
--- a/src/components/QrRendererRound.js
+++ b/src/components/QrRendererRound.js
@@ -70,7 +70,7 @@ function listPoint(props) {
     return pointList;
 }
 
-class QrRendererRound extends React.Component {
+export default class QrRendererRound extends React.Component {
     constructor(props) {
         super(props);
         if (this.props.setParamInfo) {
@@ -111,4 +111,3 @@ class QrRendererRound extends React.Component {
     }
 }
 
-export default QrRendererRound
diff --git a/src/components/Qrcode.js b/src/components/Qrcode.js
index d0636a0..37b263c 100644
--- a/src/components/Qrcode.js
+++ b/src/components/Qrcode.js
@@ -40,14 +40,6 @@ class Qrcode extends React.Component {
     paramValueBuffer;
     constructor(props) {
         super(props);
-        this.handleCreate = this.handleCreate.bind(this)
-        this.downloadSvg = this.downloadSvg.bind(this)
-        this.downloadImg = this.downloadImg.bind(this)
-        this.setParamValue = this.setParamValue.bind(this)
-        this.getParamValue = this.getParamValue.bind(this)
-        this.setParamInfo = this.setParamInfo.bind(this)
-        this.renderAdjustment = this.renderAdjustment.bind(this)
-        this.renderParamEditor = this.renderParamEditor.bind(this)
         this.state = {
             text: '',
             selectedIndex: 0,
@@ -72,7 +64,7 @@ class Qrcode extends React.Component {
         });
     }
 
-    setParamInfo(index) {
+    setParamInfo = (index) => {
         const _this = this;
         return function (params) {
             _this.paramInfoBuffer[index] = params;
@@ -82,39 +74,32 @@ class Qrcode extends React.Component {
         }
     }
 
-    setParamValue(valueIndex, value) {
+    setParamValue = (valueIndex, value) => {
         const newValue = this.state.paramValue.slice();
         newValue[this.state.selectedIndex][valueIndex] = value;
         this.setState({paramValue: newValue});
     }
 
-    getParamValue(index) {
-        const _this = this;
-        return function () {
-            return _this.state.paramValue[index];
-        }
-    }
-
-    handleCreate(e) {
+    handleCreate = (e) => {
         let text = this.state.text
         if (text.length <= 0) text = 'https://qrbtf.com/';
         this.setState({text: text, options: {text: text}, qrcode: getQrcodeData({text: text, correctLevel: this.state.correctLevel})});
         if (e) e.target.blur();
     }
 
-    downloadSvg(e) {
+    downloadSvg = (e) => {
         const style = styleList[this.state.selectedIndex]
         const el = React.createElement(style.renderer, {qrcode: this.state.qrcode, params: this.state.paramValue[this.state.selectedIndex]})
         saveSvg(style.value, ReactDOMServer.renderToString(el))
     }
 
-    downloadImg(e) {
+    downloadImg = (e) => {
         const style = styleList[this.state.selectedIndex]
         const el = React.createElement(style.renderer, {qrcode: this.state.qrcode, params: this.state.paramValue[this.state.selectedIndex]})
         saveImg(style.value, ReactDOMServer.renderToString(el), 1500, 1500)
     }
 
-    renderParamEditor(info, index) {
+    renderParamEditor = (info, index) => {
         if (info.choices) {
             return (
                 <select
@@ -149,7 +134,7 @@ class Qrcode extends React.Component {
         }
     }
 
-    renderAdjustment() {
+    renderAdjustment = () => {
         const target = this.state.paramInfo[this.state.selectedIndex];
         if (target instanceof Array) {
             return target.map((info, index) => {