isDirectory()

描述

判斷 File 物件所開啟的是否是資料夾。

語法


file.isDirectory()


參數

file：被 SD.open() 回傳的 File 物件

回傳

bool：如果 File 物件所開啟的是資料夾則回傳 true，反之則回傳 false

範例

#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) {
       // 沒有未被開啟的檔案了
       // 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 {
       // 如果是檔案會印出檔案大小
       Serial.print("\t\t");
       Serial.println(entry.size(), DEC);
     }
     entry.close();
   }
}

See Also

－ openNextFile()
－ rewindDirectory()

函式庫參考主頁面

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.