isDirectory()

描述

判断 File 物件所开启的是否是资料夹。

语法


file.isDirectory()


参数

file：被 SD.open() 回传的 File 物件

回传

bool：如果 File 物件所开启的是资料夹则回传 true，反之则回传 false

范例

#include <SD.h>

File root;

void setup()
{
  Serial.begin(9600);

  SD.begin();

  root = SD.open("/");

  printDirectory(root, 0);

  Serial.println("done!");
}

void loop()
{
  // 不做任何事
}

void printDirectory(File dir, int numTabs) {
   while(true) {

     File entry =  dir.openNextFile();
     if (! entry) {
       // 没有未被开启的档案了
       // Serial.println("**nomorefiles**");
       break;
     }
     for (uint8_t i=0; i<numTabs; i++) {
       Serial.print('\t');
     }
     Serial.print(entry.name());
     if (entry.isDirectory()) {
       Serial.println("/");
       printDirectory(entry, numTabs+1);
     } else {
       // 如果是档案会印出档案大小
       Serial.print("\t\t");
       Serial.println(entry.size(), DEC);
     }
     entry.close();
   }
}

See Also

－ openNextFile()
－ rewindDirectory()

函式库参考主页面

The text of the 86Duino reference is a modification of the Arduino reference, and is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.