diff --git a/.eslintcache b/.eslintcache
index 0b6abec..819f61b 100644
--- a/.eslintcache
+++ b/.eslintcache
@@ -1 +1 @@
-[{"/home/blobt/Documents/dev/node/study_react/src/index.js":"1","/home/blobt/Documents/dev/node/study_react/src/reportWebVitals.js":"2","/home/blobt/Documents/dev/node/study_react/src/App.js":"3","/home/blobt/Documents/dev/node/study_react/src/Weclome.js":"4","/home/blobt/Documents/dev/node/study_react/src/components/NameCard.js":"5","/home/blobt/Documents/dev/node/study_react/src/components/LikesButton.js":"6"},{"size":504,"mtime":1608691297173,"results":"7","hashOfConfig":"8"},{"size":362,"mtime":1608686231931,"results":"9","hashOfConfig":"8"},{"size":373,"mtime":1608693565331,"results":"10","hashOfConfig":"8"},{"size":445,"mtime":1608688160052,"results":"11","hashOfConfig":"8"},{"size":690,"mtime":1608692357096,"results":"12","hashOfConfig":"8"},{"size":678,"mtime":1608694636928,"results":"13","hashOfConfig":"8"},{"filePath":"14","messages":"15","errorCount":0,"warningCount":0,"fixableErrorCount":0,"fixableWarningCount":0,"usedDeprecatedRules":"16"},"1r5rxns",{"filePath":"17","messages":"18","errorCount":0,"warningCount":0,"fixableErrorCount":0,"fixableWarningCount":0,"usedDeprecatedRules":"16"},{"filePath":"19","messages":"20","errorCount":0,"warningCount":1,"fixableErrorCount":0,"fixableWarningCount":0,"source":null},{"filePath":"21","messages":"22","errorCount":0,"warningCount":0,"fixableErrorCount":0,"fixableWarningCount":0,"usedDeprecatedRules":"23"},{"filePath":"24","messages":"25","errorCount":0,"warningCount":0,"fixableErrorCount":0,"fixableWarningCount":0,"usedDeprecatedRules":"16"},{"filePath":"26","messages":"27","errorCount":0,"warningCount":1,"fixableErrorCount":0,"fixableWarningCount":0,"source":null},"/home/blobt/Documents/dev/node/study_react/src/index.js",[],["28","29"],"/home/blobt/Documents/dev/node/study_react/src/reportWebVitals.js",[],"/home/blobt/Documents/dev/node/study_react/src/App.js",["30"],"/home/blobt/Documents/dev/node/study_react/src/Weclome.js",[],["31","32"],"/home/blobt/Documents/dev/node/study_react/src/components/NameCard.js",[],"/home/blobt/Documents/dev/node/study_react/src/components/LikesButton.js",["33"],{"ruleId":"34","replacedBy":"35"},{"ruleId":"36","replacedBy":"37"},{"ruleId":"38","severity":1,"message":"39","line":1,"column":8,"nodeType":"40","messageId":"41","endLine":1,"endColumn":12},{"ruleId":"34","replacedBy":"42"},{"ruleId":"36","replacedBy":"43"},{"ruleId":"44","severity":1,"message":"45","line":14,"column":22,"nodeType":"46","endLine":14,"endColumn":32},"no-native-reassign",["47"],"no-negated-in-lhs",["48"],"no-unused-vars","'logo' is defined but never used.","Identifier","unusedVar",["47"],["48"],"react/no-direct-mutation-state","Do not mutate state directly. Use setState().","MemberExpression","no-global-assign","no-unsafe-negation"]
\ No newline at end of file
+[{"/home/blobt/Documents/dev/node/study_react/src/index.js":"1","/home/blobt/Documents/dev/node/study_react/src/reportWebVitals.js":"2","/home/blobt/Documents/dev/node/study_react/src/App.js":"3","/home/blobt/Documents/dev/node/study_react/src/Weclome.js":"4","/home/blobt/Documents/dev/node/study_react/src/components/NameCard.js":"5","/home/blobt/Documents/dev/node/study_react/src/components/LikesButton.js":"6","/home/blobt/Documents/dev/node/study_react/src/components/DigitalClock.js":"7","/home/blobt/Documents/dev/node/study_react/src/components/CommentBox.js":"8"},{"size":504,"mtime":1608691297173,"results":"9","hashOfConfig":"10"},{"size":362,"mtime":1608686231931,"results":"11","hashOfConfig":"10"},{"size":185,"mtime":1608704872704,"results":"12","hashOfConfig":"10"},{"size":445,"mtime":1608688160052,"results":"13","hashOfConfig":"10"},{"size":690,"mtime":1608692357096,"results":"14","hashOfConfig":"10"},{"size":763,"mtime":1608694717412,"results":"15","hashOfConfig":"10"},{"size":966,"mtime":1608697632407,"results":"16","hashOfConfig":"10"},{"size":1266,"mtime":1608705133968,"results":"17","hashOfConfig":"10"},{"filePath":"18","messages":"19","errorCount":0,"warningCount":0,"fixableErrorCount":0,"fixableWarningCount":0,"usedDeprecatedRules":"20"},"1r5rxns",{"filePath":"21","messages":"22","errorCount":0,"warningCount":0,"fixableErrorCount":0,"fixableWarningCount":0,"usedDeprecatedRules":"20"},{"filePath":"23","messages":"24","errorCount":0,"warningCount":0,"fixableErrorCount":0,"fixableWarningCount":0},{"filePath":"25","messages":"26","errorCount":0,"warningCount":0,"fixableErrorCount":0,"fixableWarningCount":0,"usedDeprecatedRules":"27"},{"filePath":"28","messages":"29","errorCount":0,"warningCount":0,"fixableErrorCount":0,"fixableWarningCount":0,"usedDeprecatedRules":"30"},{"filePath":"31","messages":"32","errorCount":0,"warningCount":1,"fixableErrorCount":0,"fixableWarningCount":0,"source":null},{"filePath":"33","messages":"34","errorCount":0,"warningCount":0,"fixableErrorCount":0,"fixableWarningCount":0},{"filePath":"35","messages":"36","errorCount":0,"warningCount":0,"fixableErrorCount":0,"fixableWarningCount":0},"/home/blobt/Documents/dev/node/study_react/src/index.js",[],["37","38"],"/home/blobt/Documents/dev/node/study_react/src/reportWebVitals.js",[],"/home/blobt/Documents/dev/node/study_react/src/App.js",[],"/home/blobt/Documents/dev/node/study_react/src/Weclome.js",[],["39","40"],"/home/blobt/Documents/dev/node/study_react/src/components/NameCard.js",[],["41","42"],"/home/blobt/Documents/dev/node/study_react/src/components/LikesButton.js",["43"],"/home/blobt/Documents/dev/node/study_react/src/components/DigitalClock.js",[],"/home/blobt/Documents/dev/node/study_react/src/components/CommentBox.js",[],{"ruleId":"44","replacedBy":"45"},{"ruleId":"46","replacedBy":"47"},{"ruleId":"44","replacedBy":"48"},{"ruleId":"46","replacedBy":"49"},{"ruleId":"44","replacedBy":"50"},{"ruleId":"46","replacedBy":"51"},{"ruleId":"52","severity":1,"message":"53","line":15,"column":22,"nodeType":"54","endLine":15,"endColumn":32},"no-native-reassign",["55"],"no-negated-in-lhs",["56"],["55"],["56"],["55"],["56"],"react/no-direct-mutation-state","Do not mutate state directly. Use setState().","MemberExpression","no-global-assign","no-unsafe-negation"]
\ No newline at end of file
diff --git a/src/App.js b/src/App.js
index 2ecc67e..cfda905 100644
--- a/src/App.js
+++ b/src/App.js
@@ -1,13 +1,10 @@
-import logo from './logo.svg';
 import './App.css';
-import NameCard from './components/NameCard';
-import LikesButton from './components/LikesButton';
-const tags = ['php','cpp','js'];
+import CommentBox from './components/CommentBox';
+
 function App() {
   return (
     <div className="App">
-      <NameCard name="blobt" number={15920229676} isHuman={1} tags={tags}/>
-      <LikesButton />
+      <CommentBox />
     </div>
   );
 }
diff --git a/src/components/CommentBox.js b/src/components/CommentBox.js
new file mode 100755
index 0000000..0c170fc
--- /dev/null
+++ b/src/components/CommentBox.js
@@ -0,0 +1,43 @@
+import React from 'react';
+
+
+class CommentBox extends React.Component {
+    constructor(props) {
+        super(props);
+        this.state = {
+            value: ''
+        }
+        this.change = this.change.bind(this);
+        this.submit = this.submit.bind(this);
+    }
+    change(event) {
+        this.setState({
+            value: event.target.value
+        });
+    }
+    submit(event){
+        console.log(this.state.value);
+        event.preventDefault();//阻止默认的提交行为
+    }
+    render() {
+        return (
+            <div>
+                <form className="p-5" onSubmit={this.submit}>
+                    <div className="form-group">
+                        <label>留言内容</label>
+                        <input
+                            type="text"
+                            className="form-control"
+                            placeholder="请输入内容"
+                            value={this.state.value}
+                            onChange={this.change}
+                        />
+                    </div>
+                    <button type="submit" className="btn btn-primary">留言</button>
+                </form>
+            </div>
+        )
+    }
+}
+
+export default CommentBox;
\ No newline at end of file
diff --git a/src/components/DigitalClock.js b/src/components/DigitalClock.js
new file mode 100755
index 0000000..f20f5b2
--- /dev/null
+++ b/src/components/DigitalClock.js
@@ -0,0 +1,35 @@
+import React from 'react';
+
+class DigitalClock extends React.Component{
+    constructor(props){
+        super(props);
+        this.state = {
+            date: new Date()
+        }
+    }
+    //这个是react的生命周期函数，插件挂载成功时候被调用
+    componentDidMount(){
+        this.timer = setInterval(() => {
+            this.setState({
+                date: new Date()
+            });
+        },1000);
+    }
+    //生命周期函数，组件发生改变时候被调用
+    componentDidUpdate(currentProps, currentState){
+        console.log(currentState);
+    }
+    //生命周期函数，组件卸载时候被调用
+    componentWillUnmount(){
+        clearInterval(this.timer);
+    }
+    render(){
+        return(
+            <div className="digital-clock-component jumbotron">
+                <h1>{this.state.date.toLocaleTimeString()}</h1>
+            </div>
+        )
+    }
+}
+
+export default DigitalClock;
\ No newline at end of file
diff --git a/src/components/LikesButton.js b/src/components/LikesButton.js
index 95e32e8..7dc0c3a 100755
--- a/src/components/LikesButton.js
+++ b/src/components/LikesButton.js
@@ -10,6 +10,7 @@ class LikesButton extends React.Component {
         this.increase = this.increase.bind(this)
     }
     increase(){
+        //state的值是不能直接修改的，只能使用setState方法去修改
         this.setState({
             count: ++this.state.count
         })