sketch_mar20a:10: error: 'WiFiClient' does not name a type
sketch_mar20a.ino: In function 'void setup()':
sketch_mar20a:23: error: 'WiFi' was not declared in this scope
sketch_mar20a:25: error: 'WL_CONNECTED' was not declared in this scope
sketch_mar20a.ino: In function 'void loop()':
sketch_mar20a:41: error: 'client' was not declared in this scope
sketch_mar20a:51: error: 'client' was not declared in this scope
缺少了什么库函数,在哪里可以下呢?