fix: Fix plaid background error.

Author: jaywcjlove

src/index.less

@@ -22,23 +22,26 @@
     z-index: 99;
   }
   &-demo {
+    border-radius: 3px;
     position: relative;
     overflow: auto;
     min-width: 100px;
-    &-scroll {
-      position: relative;
-      padding: 15px;
-      min-height: 80px;
-      height: 100%;
-    }
+    position: relative;
+    padding: 15px;
+    min-height: 80px;
     &-error {
       z-index: 2;
       background: #fff;
       width: 100%;
       height: 100%;
       margin-bottom: 0 !important;
-      color: #dc3545;
-      background-color: #fbeff0;
+      color: #dc3545 !important;
+    }
+    &-bgPlaid:not(&-error) {
+      background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg'%3E%3Cpattern id='a' width='16' height='16' patternUnits='userSpaceOnUse'%3E%3Cpath fill='rgba(0, 0, 0, 0.06)' d='M0 0h8v8H0zM8 8h8v8H8z'/%3E%3C/pattern%3E%3Crect fill='url(%23a)' width='100%25' height='100%25'/%3E%3C/svg%3E");
+    }
+    &-source.error {
+      display: none;
     }
   }
   &-bgPlaid {

src/index.tsx

@@ -146,23 +146,21 @@ export default class CodePreview extends React.PureComponent<ICodePreviewProps,
         {!noPreview && (
           <div
             ref={this.demoDom}
-            className={`${prefixCls}-demo`}
+            className={classnames(`${prefixCls}-demo`, {
+              [`${prefixCls}-demo-bgPlaid`]: !bgWhite,
+              [`${prefixCls}-demo-error`]: this.state.errorMessage,
+            })}
             style={{
               flex: 1,
               ...(this.state.width === 1 ? { width: '100%'} : {})
             }}
           >
-            {!bgWhite && (
-              <div className={`${prefixCls}-bgPlaid`}> {icon.bgPlaid} </div>
-            )}
             {this.state.errorMessage && (
-              <pre className={`${prefixCls}-demo-error`}>
+              <pre>
                 <code>{this.state.errorMessage}</code>
               </pre>
             )}
-            <div className={classnames(`${prefixCls}-demo-scroll`)}>
-              <div className={`${prefixCls}-demo-source`} id={this.playerId} />
-            </div>
+            <div className={classnames(`${prefixCls}-demo-source`, { ['error']: this.state.errorMessage })} id={this.playerId} />
           </div>
         )}
         {!noCode && (