Ardiuno之esp32 st7789显示屏利用TJpg_Decoder库读取sd卡中的图片

前言：

        因为空闲时间比较多，看了不少嵌入式开发的教程，过年期间整了一块240*240的st7789屏幕，之前使用micropython开发，但是感觉图片加载速度慢，而且库非常少，没办法读取sd卡里面的图片。有个别大佬的教程倒是很详细，但不开源，所以转战Ardiuno，也算是零基础入门了。

        网上不少案例可以显示图片，但大多都是将图片转成数组，放入内存编译上传。以esp32的内存，根本存不了几张。那些教程就不再细说了，有耐心的自己研究。

        这两天看了不少教程，终于解决了显示SD卡中的图片，并且做了一些优化。起初用的是JPEGDecoder这个库，但是解析图片速度太慢了。所以换成了TJpg_Decoder库，点击这里直接进去下载，然后安装。

一、TFT_eSPI库修改配置

        这个很简单，就是User_Setup.h文件中改一些宏定义，注意自己屏幕的尺寸和型号，最重要的是引脚。

//                            USER DEFINED SETTINGS
//   Set driver type, fonts to be loaded, pins used and SPI control method etc.
//
//   See the User_Setup_Select.h file if you wish to be able to define multiple
//   setups and then easily select which setup file is used by the compiler.
//
//   If this file is edited correctly then all the library example sketches should
//   run without the need to make any more changes for a particular hardware setup!
//   Note that some sketches are designed for a particular TFT pixel width/height

// User defined information reported by "Read_User_Setup" test & diagnostics example
#define USER_SETUP_INFO "User_Setup"

// Define to disable all #warnings in library (can be put in User_Setup_Select.h)
//#define DISABLE_ALL_LIBRARY_WARNINGS

// ##################################################################################
//
// Section 1. Call up the right driver file and any options for it
//
// ##################################################################################

// Define STM32 to invoke optimised processor support (only for STM32)
//#define STM32

// Defining the STM32 board allows the library to optimise the performance
// for UNO compatible "MCUfriend" style shields
//#define NUCLEO_64_TFT
//#define NUCLEO_144_TFT

// STM32 8-bit parallel only:
// If STN32 Port A or B pins 0-7 are used for 8-bit parallel data bus bits 0-7
// then this will improve rendering performance by a factor of ~8x
//#define STM_PORTA_DATA_BUS
//#define STM_PORTB_DATA_BUS

// Tell the library to use parallel mode (otherwise SPI is assumed)
//#define TFT_PARALLEL_8_BIT
//#defined TFT_PARALLEL_16_BIT // **** 16-bit parallel ONLY for RP2040 processor ****

// Display type -  only define if RPi display
//#define RPI_DISPLAY_TYPE // 20MHz maximum SPI

// Only define one driver, the other ones must be commented out
//#define ILI9341_DRIVER       // Generic driver for common displays
//#define ILI9341_2_DRIVER     // Alternative ILI9341 driver, see https://github.com/Bodmer/TFT_eSPI/issues/1172
//#define ST7735_DRIVER      // Define additional parameters below for this display
//#define ILI9163_DRIVER     // Define additional parameters below for this display
//#define S6D02A1_DRIVER
//#define RPI_ILI9486_DRIVER // 20MHz maximum SPI
//#define HX8357D_DRIVER
//#define ILI9481_DRIVER
//#define ILI9486_DRIVER
//#define ILI9488_DRIVER     // WARNING: Do not connect ILI9488 display SDO to MISO if other devices share the SPI bus (TFT SDO does NOT tristate when CS is high)
#define ST7789_DRIVER      // Full configuration option, define additional parameters below for this display
//#define ST7789_2_DRIVER    // Minimal configuration option, define additional parameters below for this display
//#define R61581_DRIVER
//#define RM68140_DRIVER
//#define ST7796_DRIVER
//#define SSD1351_DRIVER
//#define SSD1963_480_DRIVER
//#define SSD1963_800_DRIVER
//#define SSD1963_800ALT_DRIVER
//#define ILI9225_DRIVER
//#define GC9A01_DRIVER

// Some displays support SPI reads via the MISO pin, other displays have a single
// bi-directional SDA pin and the library will try to read this via the MOSI line.
// To use the SDA line for reading data from the TFT uncomment the following line:

// #define TFT_SDA_READ      // This option is for ESP32 ONLY, tested with ST7789 and GC9A01 display only

// For ST7735, ST7789 and ILI9341 ONLY, define the colour order IF the blue and red are swapped on your display
// Try ONE option at a time to find the correct colour order for your display

//  #define TFT_RGB_ORDER TFT_RGB  // Colour order Red-Green-Blue
#define TFT_RGB_ORDER TFT_BGR  // Colour order Blue-Green-Red

// For M5Stack ESP32 module with integrated ILI9341 display ONLY, remove // in line below

// #define M5STACK

// For ST7789, ST7735, ILI9163 and GC9A01 ONLY, define the pixel width and height in portrait orientation
// #define TFT_WIDTH  80
// #define TFT_WIDTH  128
// #define TFT_WIDTH  172 // ST7789 172 x 320
// #define TFT_WIDTH  170 // ST7789 170 x 320
#define TFT_WIDTH  240 // ST7789 240 x 240 and 240 x 320
// #define TFT_HEIGHT 160
// #define TFT_HEIGHT 128
#define TFT_HEIGHT 240 // ST7789 240 x 240
// #define TFT_HEIGHT 320 // ST7789 240 x 320
// #define TFT_HEIGHT 240 // GC9A01 240 x 240

// For ST7735 ONLY, define the type of display, originally this was based on the
// colour of the tab on the screen protector film but this is not always true, so try
// out the different options below if the screen does not display graphics correctly,
// e.g. colours wrong, mirror images, or stray pixels at the edges.
// Comment out ALL BUT ONE of these options for a ST7735 display driver, save this
// this User_Setup file, then rebuild and upload the sketch to the board again:

// #define ST7735_INITB
// #define ST7735_GREENTAB
// #define ST7735_GREENTAB2
// #define ST7735_GREENTAB3
// #define ST7735_GREENTAB128    // For 128 x 128 display
// #define ST7735_GREENTAB160x80 // For 160 x 80 display (BGR, inverted, 26 offset)
// #define ST7735_ROBOTLCD       // For some RobotLCD Arduino shields (128x160, BGR, https://docs.arduino.cc/retired/getting-started-guides/TFT)
// #define ST7735_REDTAB
// #define ST7735_BLACKTAB
// #define ST7735_REDTAB160x80   // For 160 x 80 display with 24 pixel offset

// If colours are inverted (white shows as black) then uncomment one of the next
// 2 lines try both options, one of the options should correct the inversion.

// #define TFT_INVERSION_ON
// #define TFT_INVERSION_OFF


// ##################################################################################
//
// Section 2. Define the pins that are used to interface with the display here
//
// ##################################################################################

// If a backlight control signal is available then define the TFT_BL pin in Section 2
// below. The backlight will be turned ON when tft.begin() is called, but the library
// needs to know if the LEDs are ON with the pin HIGH or LOW. If the LEDs are to be
// driven with a PWM signal or turned OFF/ON then this must be handled by the user
// sketch. e.g. with digitalWrite(TFT_BL, LOW);

// #define TFT_BL   32            // LED back-light control pin
// #define TFT_BACKLIGHT_ON HIGH  // Level to turn ON back-light (HIGH or LOW)



// We must use hardware SPI, a minimum of 3 GPIO pins is needed.
// Typical setup for ESP8266 NodeMCU ESP-12 is :
//
// Display SDO/MISO  to NodeMCU pin D6 (or leave disconnected if not reading TFT)
// Display LED       to NodeMCU pin VIN (or 5V, see below)
// Display SCK       to NodeMCU pin D5
// Display SDI/MOSI  to NodeMCU pin D7
// Display DC (RS/AO)to NodeMCU pin D3
// Display RESET     to NodeMCU pin D4 (or RST, see below)
// Display CS        to NodeMCU pin D8 (or GND, see below)
// Display GND       to NodeMCU pin GND (0V)
// Display VCC       to NodeMCU 5V or 3.3V
//
// The TFT RESET pin can be connected to the NodeMCU RST pin or 3.3V to free up a control pin
//
// The DC (Data Command) pin may be labelled AO or RS (Register Select)
//
// With some displays such as the ILI9341 the TFT CS pin can be connected to GND if no more
// SPI devices (e.g. an SD Card) are connected, in this case comment out the #define TFT_CS
// line below so it is NOT defined. Other displays such at the ST7735 require the TFT CS pin
// to be toggled during setup, so in these cases the TFT_CS line must be defined and connected.
//
// The NodeMCU D0 pin can be used for RST
//
//
// Note: only some versions of the NodeMCU provide the USB 5V on the VIN pin
// If 5V is not available at a pin you can use 3.3V but backlight brightness
// will be lower.


// ###### EDIT THE PIN NUMBERS IN THE LINES FOLLOWING TO SUIT YOUR ESP8266 SETUP ######

// For NodeMCU - use pin numbers in the form PIN_Dx where Dx is the NodeMCU pin designation
#define TFT_MISO  PIN_D6  // Automatically assigned with ESP8266 if not defined
#define TFT_MOSI  PIN_D7  // Automatically assigned with ESP8266 if not defined
#define TFT_SCLK  PIN_D5  // Automatically assigned with ESP8266 if not defined

#define TFT_CS    PIN_D8  // Chip select control pin D8
#define TFT_DC    PIN_D3  // Data Command control pin
#define TFT_RST   PIN_D4  // Reset pin (could connect to NodeMCU RST, see next line)
//#define TFT_RST  -1     // Set TFT_RST to -1 if the display RESET is connected to NodeMCU RST or 3.3V


//#define TFT_BL PIN_D1  // LED back-light (only for ST7789 with backlight control pin)

//#define TOUCH_CS PIN_D2     // Chip select pin (T_CS) of touch screen

//#define TFT_WR PIN_D2       // Write strobe for modified Raspberry Pi TFT only


// ######  FOR ESP8266 OVERLAP MODE EDIT THE PIN NUMBERS IN THE FOLLOWING LINES  ######

// Overlap mode shares the ESP8266 FLASH SPI bus with the TFT so has a performance impact
// but saves pins for other functions. It is best not to connect MISO as some displays
// do not tristate that line when chip select is high!
// Note: Only one SPI device can share the FLASH SPI lines, so a SPI touch controller
// cannot be connected as well to the same SPI signals.
// On NodeMCU 1.0 SD0=MISO, SD1=MOSI, CLK=SCLK to connect to TFT in overlap mode
// On NodeMCU V3  S0 =MISO, S1 =MOSI, S2 =SCLK
// In ESP8266 overlap mode the following must be defined

//#define TFT_SPI_OVERLAP

// In ESP8266 overlap mode the TFT chip select MUST connect to pin D3
//#define TFT_CS   PIN_D3
//#define TFT_DC   PIN_D5  // Data Command control pin
//#define TFT_RST  PIN_D4  // Reset pin (could connect to NodeMCU RST, see next line)
//#define TFT_RST  -1  // Set TFT_RST to -1 if the display RESET is connected to NodeMCU RST or 3.3V


// ###### EDIT THE PIN NUMBERS IN THE LINES FOLLOWING TO SUIT YOUR ESP32 SETUP   ######

// For ESP32 Dev board (only tested with ILI9341 display)
// The hardware SPI can be mapped to any pins

#define TFT_MISO 19
#define TFT_MOSI 23
#define TFT_SCLK 18
#define TFT_CS   5  // Chip select control pin
#define TFT_DC    2  // Data Command control pin
#define TFT_RST   4  // Reset pin (could connect to RST pin)
//#define TFT_RST  -1  // Set TFT_RST to -1 if display RESET is connected to ESP32 board RST

// For ESP32 Dev board (only tested with GC9A01 display)
// The hardware SPI can be mapped to any pins

//#define TFT_MOSI 15 // In some display driver board, it might be written as "SDA" and so on.
//#define TFT_SCLK 14
//#define TFT_CS   5  // Chip select control pin
//#define TFT_DC   27  // Data Command control pin
//#define TFT_RST  33  // Reset pin (could connect to Arduino RESET pin)
//#define TFT_BL   22  // LED back-light

//#define TOUCH_CS 21     // Chip select pin (T_CS) of touch screen

//#define TFT_WR 22    // Write strobe for modified Raspberry Pi TFT only

// For the M5Stack module use these #define lines
//#define TFT_MISO 19
//#define TFT_MOSI 23
//#define TFT_SCLK 18
//#define TFT_CS   14  // Chip select control pin
//#define TFT_DC   27  // Data Command control pin
//#define TFT_RST  33  // Reset pin (could connect to Arduino RESET pin)
//#define TFT_BL   32  // LED back-light (required for M5Stack)

// ######       EDIT THE PINs BELOW TO SUIT YOUR ESP32 PARALLEL TFT SETUP        ######

// The library supports 8-bit parallel TFTs with the ESP32, the pin
// selection below is compatible with ESP32 boards in UNO format.
// Wemos D32 boards need to be modified, see diagram in Tools folder.
// Only ILI9481 and ILI9341 based displays have been tested!

// Parallel bus is only supported for the STM32 and ESP32
// Example below is for ESP32 Parallel interface with UNO displays

// Tell the library to use 8-bit parallel mode (otherwise SPI is assumed)
//#define TFT_PARALLEL_8_BIT

// The ESP32 and TFT the pins used for testing are:
//#define TFT_CS   33  // Chip select control pin (library pulls permanently low
//#define TFT_DC   15  // Data Command control pin - must use a pin in the range 0-31
//#define TFT_RST  32  // Reset pin, toggles on startup

//#define TFT_WR    4  // Write strobe control pin - must use a pin in the range 0-31
//#define TFT_RD    2  // Read strobe control pin

//#define TFT_D0   12  // Must use pins in the range 0-31 for the data bus
//#define TFT_D1   13  // so a single register write sets/clears all bits.
//#define TFT_D2   26  // Pins can be randomly assigned, this does not affect
//#define TFT_D3   25  // TFT screen update performance.
//#define TFT_D4   17
//#define TFT_D5   16
//#define TFT_D6   27
//#define TFT_D7   14

// ######       EDIT THE PINs BELOW TO SUIT YOUR STM32 SPI TFT SETUP        ######

// The TFT can be connected to SPI port 1 or 2
//#define TFT_SPI_PORT 1 // SPI port 1 maximum clock rate is 55MHz
//#define TFT_MOSI PA7
//#define TFT_MISO PA6
//#define TFT_SCLK PA5

//#define TFT_SPI_PORT 2 // SPI port 2 maximum clock rate is 27MHz
//#define TFT_MOSI PB15
//#define TFT_MISO PB14
//#define TFT_SCLK PB13

// Can use Ardiuno pin references, arbitrary allocation, TFT_eSPI controls chip select
//#define TFT_CS   D5 // Chip select control pin to TFT CS
//#define TFT_DC   D6 // Data Command control pin to TFT DC (may be labelled RS = Register Select)
//#define TFT_RST  D7 // Reset pin to TFT RST (or RESET)
// OR alternatively, we can use STM32 port reference names PXnn
//#define TFT_CS   PE11 // Nucleo-F767ZI equivalent of D5
//#define TFT_DC   PE9  // Nucleo-F767ZI equivalent of D6
//#define TFT_RST  PF13 // Nucleo-F767ZI equivalent of D7

//#define TFT_RST  -1   // Set TFT_RST to -1 if the display RESET is connected to processor reset
                        // Use an Arduino pin for initial testing as connecting to processor reset
                        // may not work (pulse too short at power up?)

// ##################################################################################
//
// Section 3. Define the fonts that are to be used here
//
// ##################################################################################

// Comment out the #defines below with // to stop that font being loaded
// The ESP8366 and ESP32 have plenty of memory so commenting out fonts is not
// normally necessary. If all fonts are loaded the extra FLASH space required is
// about 17Kbytes. To save FLASH space only enable the fonts you need!

#define LOAD_GLCD   // Font 1. Original Adafruit 8 pixel font needs ~1820 bytes in FLASH
#define LOAD_FONT2  // Font 2. Small 16 pixel high font, needs ~3534 bytes in FLASH, 96 characters
#define LOAD_FONT4  // Font 4. Medium 26 pixel high font, needs ~5848 bytes in FLASH, 96 characters
#define LOAD_FONT6  // Font 6. Large 48 pixel font, needs ~2666 bytes in FLASH, only characters 1234567890:-.apm
#define LOAD_FONT7  // Font 7. 7 segment 48 pixel font, needs ~2438 bytes in FLASH, only characters 1234567890:-.
#define LOAD_FONT8  // Font 8. Large 75 pixel font needs ~3256 bytes in FLASH, only characters 1234567890:-.
//#define LOAD_FONT8N // Font 8. Alternative to Font 8 above, slightly narrower, so 3 digits fit a 160 pixel TFT
#define LOAD_GFXFF  // FreeFonts. Include access to the 48 Adafruit_GFX free fonts FF1 to FF48 and custom fonts

// Comment out the #define below to stop the SPIFFS filing system and smooth font code being loaded
// this will save ~20kbytes of FLASH
#define SMOOTH_FONT


// ##################################################################################
//
// Section 4. Other options
//
// ##################################################################################

// For RP2040 processor and SPI displays, uncomment the following line to use the PIO interface.
//#define RP2040_PIO_SPI // Leave commented out to use standard RP2040 SPI port interface

// For RP2040 processor and 8 or 16-bit parallel displays:
// The parallel interface write cycle period is derived from a division of the CPU clock
// speed so scales with the processor clock. This means that the divider ratio may need
// to be increased when overclocking. It may also need to be adjusted dependant on the
// display controller type (ILI94341, HX8357C etc.). If RP2040_PIO_CLK_DIV is not defined
// the library will set default values which may not suit your display.
// The display controller data sheet will specify the minimum write cycle period. The
// controllers often work reliably for shorter periods, however if the period is too short
// the display may not initialise or graphics will become corrupted.
// PIO write cycle frequency = (CPU clock/(4 * RP2040_PIO_CLK_DIV))
//#define RP2040_PIO_CLK_DIV 1 // 32ns write cycle at 125MHz CPU clock
//#define RP2040_PIO_CLK_DIV 2 // 64ns write cycle at 125MHz CPU clock
//#define RP2040_PIO_CLK_DIV 3 // 96ns write cycle at 125MHz CPU clock

// For the RP2040 processor define the SPI port channel used (default 0 if undefined)
//#define TFT_SPI_PORT 1 // Set to 0 if SPI0 pins are used, or 1 if spi1 pins used

// For the STM32 processor define the SPI port channel used (default 1 if undefined)
//#define TFT_SPI_PORT 2 // Set to 1 for SPI port 1, or 2 for SPI port 2

// Define the SPI clock frequency, this affects the graphics rendering speed. Too
// fast and the TFT driver will not keep up and display corruption appears.
// With an ILI9341 display 40MHz works OK, 80MHz sometimes fails
// With a ST7735 display more than 27MHz may not work (spurious pixels and lines)
// With an ILI9163 display 27 MHz works OK.

// #define SPI_FREQUENCY   1000000
// #define SPI_FREQUENCY   5000000
// #define SPI_FREQUENCY  10000000
// #define SPI_FREQUENCY  20000000
#define SPI_FREQUENCY  27000000
// #define SPI_FREQUENCY  40000000
// #define SPI_FREQUENCY  55000000 // STM32 SPI1 only (SPI2 maximum is 27MHz)
// #define SPI_FREQUENCY  80000000

// Optional reduced SPI frequency for reading TFT
#define SPI_READ_FREQUENCY  20000000

// The XPT2046 requires a lower SPI clock rate of 2.5MHz so we define that here:
#define SPI_TOUCH_FREQUENCY  2500000

// The ESP32 has 2 free SPI ports i.e. VSPI and HSPI, the VSPI is the default.
// If the VSPI port is in use and pins are not accessible (e.g. TTGO T-Beam)
// then uncomment the following line:
//#define USE_HSPI_PORT

// Comment out the following #define if "SPI Transactions" do not need to be
// supported. When commented out the code size will be smaller and sketches will
// run slightly faster, so leave it commented out unless you need it!

// Transaction support is needed to work with SD library but not needed with TFT_SdFat
// Transaction support is required if other SPI devices are connected.

// Transactions are automatically enabled by the library for an ESP32 (to use HAL mutex)
// so changing it here has no effect

// #define SUPPORT_TRANSACTIONS

二、TFT显示屏接线方式

        厂家不同，显示的引脚名称不一样，但大同小异。

TFT_MISO	----	19
TFT_MOSI	SDA	23
TFT_SCLK	SCL|SCK	18
TFT_CS	CS	5
TFT_DC	DC	2
TFT_RST	RST|RES	4

三、SD卡模块接线方式

        sd卡模块都差不多，接线方式可以自定义。注意一下，重点来了，与TFT接线不要冲突，之前我就踩了这个坑，还一直没发现。如果共用引脚，会导致要么显示屏不能显示，要么SD卡不能读取。这是因为SPI不能共总线，是个很大的坑。

MISO	12
MOSI	13
SCLK	14
CS	15

四、实现代码

        话不多说，上代码。注意SD卡的初始化方式，改用HSPI。再就是烧录的时候，把sd卡模块的MISO 接线拔掉，不然烧录失败。烧录完后，MISO 重新插上，然后断电重启就行了。

// Example for library:
// https://github.com/Bodmer/TJpg_Decoder

// This example if for an ESP8266 or ESP32, it renders a Jpeg file
// that is stored in a SD card file. The test image is in the sketch
// "data" folder (press Ctrl+K to see it). You must save the image
// to the SD card using you PC.

// Include the jpeg decoder library
#include 

// Include SD
#define FS_NO_GLOBALS
#include 
#ifdef ESP32
  #include "SPIFFS.h" // ESP32 only
#endif


SPIClass sdSPI(HSPI);
// #define SD_MISO     13
// #define SD_MOSI     15
// #define SD_SCLK     17
// #define SD_CS       14
#define SD_MISO     12
#define SD_MOSI     13
#define SD_SCLK     14
#define SD_CS       15
// Include the TFT library https://github.com/Bodmer/TFT_eSPI
#include "SPI.h"
#include               // Hardware-specific library
TFT_eSPI tft = TFT_eSPI();         // Invoke custom library


// This next function will be called during decoding of the jpeg file to
// render each block to the TFT.  If you use a different TFT library
// you will need to adapt this function to suit.
bool tft_output(int16_t x, int16_t y, uint16_t w, uint16_t h, uint16_t* bitmap)
{
   // Stop further decoding as image is running off bottom of screen
  if ( y >= tft.height() ) return 0;

  // This function will clip the image block rendering automatically at the TFT boundaries
  tft.pushImage(x, y, w, h, bitmap);

  // This might work instead if you adapt the sketch to use the Adafruit_GFX library
  // tft.drawRGBBitmap(x, y, bitmap, w, h);

  // Return 1 to decode next block
  return 1;
}


void setup()
{
  Serial.begin(115200);
  Serial.println("\n\n Testing TJpg_Decoder library");
  sdSPI.begin(SD_SCLK, SD_MISO, SD_MOSI, SD_CS);
  if (!SD.begin(SD_CS, sdSPI)){
    Serial.println(F("SD.begin failed!"));
    while (1) delay(0);
  }
  Serial.println("\r\nInitialisation done.");

  // Initialise the TFT
  tft.begin();
  tft.setTextColor(0xFFFF, 0x0000);
  tft.fillScreen(TFT_BLACK);
  tft.setSwapBytes(true); // We need to swap the colour bytes (endianess)

  // The jpeg image can be scaled by a factor of 1, 2, 4, or 8
  TJpgDec.setJpgScale(1);

  // The decoder must be given the exact name of the rendering function above
  TJpgDec.setCallback(tft_output);
}

void loop()
{

  uint32_t t = millis();
  uint16_t w = 0, h = 0;
  // TJpgDec.getSdJpgSize(&w, &h, "/img.jpg");
  // TJpgDec.drawSdJpg(0, 0, "/img.jpg");
  // delay(2000);

  File dataFolder = SD.open("/data");
  if (!dataFolder) {
    Serial.println("无法打开 data 文件夹");
    return;
  }
  if (!dataFolder.isDirectory()) {
    Serial.println("/data 不是一个文件夹");
    dataFolder.close();
    return;
  }
  File entry;
  while (entry = dataFolder.openNextFile()) {
    if (!entry.isDirectory()) {
      // 检查文件扩展名是否为 .jpg
      const char* filename = entry.name();
      int len = strlen(filename);
      if (len >= 4 && strcasecmp(filename + len - 4, ".jpg") == 0) {
        Serial.print("找到 JPEG 文件: ");
        Serial.println(filename);
        char fullPath[50];
        sprintf(fullPath, "/data/%s", filename);
        TJpgDec.getSdJpgSize(&w, &h, fullPath);
        TJpgDec.drawSdJpg(0, 0, fullPath);
        delay(3000);
      }
    }
    entry.close();
  }
  dataFolder.close();
}

五、最终效果

        网上找的原图，用python压缩一下大小就行了，刷新速度很快。下一步研究下怎么播放视频。

import os
from PIL import Image


def compress_images(folder_path, output_folder):
    # 检查输出文件夹是否存在，如果不存在则创建
    if not os.path.exists(output_folder):
        os.makedirs(output_folder)

    # 遍历指定文件夹下的所有文件
    for filename in os.listdir(folder_path):
        file_path = os.path.join(folder_path, filename)

        # 检查文件是否为图片文件（可以根据需要添加更多图片扩展名）
        if os.path.isfile(file_path) and filename.lower().endswith(('.png', '.jpg', '.jpeg')):
            try:
                # 打开图片
                image = Image.open(file_path)

                # 压缩图片到 240x240 大小
                resized_image = image.resize((240, 240), Image.LANCZOS)

                # 构建输出文件路径
                output_path = os.path.join(output_folder, filename)

                # 保存压缩后的图片
                resized_image.save(output_path)
                print(f"已压缩并保存: {filename}")
            except Exception as e:
                print(f"处理 {filename} 时出错: {e}")


# 示例调用
input_folder = 'F:\小说\img'  # 替换为实际的输入文件夹路径
output_folder = 'img'  # 替换为实际的输出文件夹路径
compress_images(input_folder, output_folder)