Pebble Date图层

Question

这段代码是当你在网站上完成前两个教程时得到的，任何涉及日期(图层，字体)的东西都是我添加的。我已经将其作为子层添加到窗口中，但是什么也没有出现。

#include <pebble.h>

static Window *s_main_window;
static TextLayer *s_time_layer;
static TextLayer *s_date_layer;
static GFont s_date_font;
static GFont s_time_font;
static BitmapLayer *s_background_layer;
static GBitmap *s_background_bitmap;

static void update_time() {
  // Get a tm structure
  time_t temp = time(NULL); 
//  time_t temp1 = date(NULL);
  struct tm *tick_time = localtime(&temp);
 // struct dt *tick_date = localdate(&temp1);

  // Create a long-lived buffer
  static char buffer[] = "00:00:00";
  static char buffer1[] = "00:00:00";

  // Write the current hours and minutes into the buffer
  if(clock_is_24h_style() == true) {
    // Use 24 hour format
    strftime(buffer, sizeof("00:00:00"), "%H:%M:%S", tick_time);
  } else {
    // Use 12 hour format
    strftime(buffer, sizeof("00:00:00"), "%I:%M:%S", tick_time);
  }

  // Display this time on the TextLayer
  text_layer_set_text(s_time_layer, buffer);

  strftime(buffer1, sizeof("mm/dd/yy"), "%m/%d/%y", tick_time);

  // Display this date on the TextLayer
  text_layer_set_text(s_date_layer, buffer1);
}

static void main_window_load(Window *window) {

  // Create GBitmap, then set to created BitmapLayer
  s_background_bitmap = gbitmap_create_with_resource(RESOURCE_ID_IMAGE_BACKGROUND);
  s_background_layer = bitmap_layer_create(GRect(0, 0, 144, 168));
  bitmap_layer_set_bitmap(s_background_layer, s_background_bitmap);
  layer_add_child(window_get_root_layer(window), bitmap_layer_get_layer(s_background_layer));

  // Create time TextLayer
  //s_time_layer = text_layer_create(GRect(0, 55, 144, 50));
  s_time_layer = text_layer_create(GRect(4, 62, 139, 50));
  text_layer_set_background_color(s_time_layer, GColorClear);
  text_layer_set_text_color(s_time_layer, GColorBlack);

  // Create date DateLayer
  //s_time_layer = text_layer_create(GRect(0, 55, 144, 50));
  s_date_layer = text_layer_create(GRect(8, 184, 139, 50));
  text_layer_set_background_color(s_date_layer, GColorClear);
  text_layer_set_text_color(s_date_layer, GColorWhite);

  // Create GFont for Time and Date
  s_time_font = fonts_load_custom_font(resource_get_handle(RESOURCE_ID_FONT_PERFECT_DOS_30));
  s_date_font = fonts_load_custom_font(resource_get_handle(RESOURCE_ID_FONT_PERFECT_DOS_30));

  // Apply to TextLayer
  text_layer_set_font(s_time_layer, s_time_font);

  //Apply to DateLayer
  text_layer_set_font(s_date_layer, s_date_font);

  //Test text on watchface
  //text_layer_set_text(s_time_layer, "00:00");

  // Improve the layout to be more like a watchface
  //text_layer_set_font(s_time_layer, fonts_get_system_font(FONT_KEY_BITHAM_30_BLACK));
  text_layer_set_text_alignment(s_time_layer, GTextAlignmentCenter);
  text_layer_set_text_alignment(s_date_layer, GAlignBottom);

  // Add time as a child layer to the Window's root layer
  layer_add_child(window_get_root_layer(window), text_layer_get_layer(s_time_layer));

  //Add date as a child layer to the Window's root layer
  layer_add_child(window_get_root_layer(window), text_layer_get_layer(s_date_layer));
}

static void main_window_unload(Window *window) {

  // Unload GFonts
  fonts_unload_custom_font(s_time_font);
  fonts_unload_custom_font(s_date_font);

  // Destroy TextLayer
  text_layer_destroy(s_time_layer);

  //Destroy DateLayer
  text_layer_destroy(s_date_layer);

  // Destroy GBitmap
  gbitmap_destroy(s_background_bitmap);

  // Destroy BitmapLayer
  bitmap_layer_destroy(s_background_layer);

}

static void tick_handler(struct tm *tick_time, TimeUnits units_changed) {
  update_time();
}

static void init() {

  // Create main Window element and assign to pointer
  s_main_window = window_create();

  // Set handlers to manage the elements inside the Window
  window_set_window_handlers(s_main_window, (WindowHandlers) {
    .load = main_window_load,
    .unload = main_window_unload
  });

  // Show the Window on the watch, with animated=true
  window_stack_push(s_main_window, true);

  // Make sure the time and date is displayed from the start
  update_time();

  // Register with TickTimerService
  tick_timer_service_subscribe(MINUTE_UNIT, tick_handler);
  tick_timer_service_subscribe(SECOND_UNIT, tick_handler);
  tick_timer_service_subscribe(DAY_UNIT, tick_handler);
  tick_timer_service_subscribe(MONTH_UNIT, tick_handler);
  tick_timer_service_subscribe(YEAR_UNIT, tick_handler);

}

static void deinit() {

    // Destroy Window
    window_destroy(s_main_window);

}

int main(void) {
  init();
  app_event_loop();
  deinit();
}

Answer 1

我在CloudPebble中测试了它，没有任何问题(我不得不删除你没有包含的bg图像和字体)。你犯了以下错误：

s_date_layer = text_layer_create(GRect(8, 184, 139, 50));

Y值184从屏幕底部(168)下方开始

text_layer_set_text_color(s_date_layer, GColorWhite);

它可能会在白色上绘制白色(没有看到您的背景)

tick_timer_service_subscribe(YEAR_UNIT, tick_handler);

只有最后一次订阅才算数，所以你要么只做如下操作：(适合你的用法)

tick_timer_service_subscribe(SECOND_UNIT, tick_handler);

或者在一次调用中添加/或所需的值，例如：

tick_timer_service_subscribe(SECOND_UNIT | DAY_UNIT, tick_handler);