Update README.MD

AKAChing · web-flow · commit 7993a9c647cd · 2020-03-09T13:33:59.000+08:00
diff --git a/CopyText/README.MD b/CopyText/README.MD
@@ -1,31 +1,34 @@
 # Copy text
 > Code
 ``` javascript
-  function copyText( content = '', successInfo = 'copy success') {
-    // it works by simulating the input element
-    let oInput = document.createElement('input')
-    oInput.id = 'copyInput'
-    oInput.value = content
-    document.body.appendChild(oInput)
-    oInput.select()
-    document.execCommand('Copy')
-    oInput.style.display = 'none'
-    alert(successInfo)
-    // remove the element after copied
-    oInput.parentNode.removeChild(oInput)
-  }
+function copyText( content = '') {
+  return new Promise(resolve => {
+    setTimeout(() => {
+      let oInput = document.createElement('input')
+      oInput.id = 'copyInput'
+      oInput.value = content
+      document.body.appendChild(oInput)
+      oInput.select()
+      document.execCommand('Copy')
+      oInput.style.display = 'none'
+      oInput.parentNode.removeChild(oInput)
+      resolve()
+    }, 0)
+  })
+}
 ```
 
 > Example
 ``` javascript
   `<span id="info">test infomation<span>`
   let target = document.getElementById('info')
-  copyText(target)
+  copyText(target).then(() => {
+    console.log('copied success')
+  })
 ```
 
 > Params
 
 | Params | Description | Type | Default |
 | :------: | :-----------: | :----: | :-------: |
 | content | the content you want to copy | string | '' |
-| successInfo | the message you want to alert after copied | string | 'copy success' |
