no message

basic/6/P06.html

@@ -57,8 +57,8 @@
                 return "getSnapshotBeforeUpdate"
             }
             componentDidUpdate(preProps,preState,snapshotValue){
-                console.log(snapshotValue)
-                // console.log(preProps,preState)
+                // console.log(snapshotValue)
+                console.log(preProps,preState)
                 // console.log('componentDidUpdate') 
             }
         }

chenxuan1/src/pages/life.jsx

@@ -5,16 +5,24 @@ class Child extends React.Component{
   componentDidMount() {
     console.log('componentDidMount');
   }
-  componentDidUpdate() {
-    console.log('componentDidUpdate');
+  shouldComponentUpdate(){
+      console.log('shouldComponentUpdate') 
+      return true
+  }
+  getSnapshotBeforeUpdate(prevProps,prevState){
+    console.log(prevState)
+    return "getSnapshotBeforeUpdate"
+  }
+  componentDidUpdate(preProps,preState,snapshotValue) {
+    console.log(preProps,preState,snapshotValue);
   }
   // 劫持state
   // state属性与props相关时
   static getDerivedStateFromProps(props,state){
-    console.log("getDerivedStateFromProps")
-    // return {count:"xxx"}
-    return null;
-}
+      console.log("getDerivedStateFromProps")
+      // return {count:"xxx"}
+      return null;
+  }
   add=()=>{
       let {count}=this.state;
       count+=1;
@@ -24,7 +32,7 @@ class Child extends React.Component{
     return (
       <div>
         <h1>子组件</h1>
-        <h3>state:{this.state.count}</h3>
+        {/* <h3>state:{this.state.count}</h3> */}
         <h3>props:{this.props.name}</h3>
         <button onClick={this.add}>子组件点击事件</button>
       </div>