Logging（日志）

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LVGL has a built-in Log module to inform the user about what is happening in the library.

LVGL 有内置的 Log 模块来向用户告知库中发生的事情。

Log level（日志等级）

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To enable logging, set LV_USE_LOG in lv_conf.h and set LV_LOG_LEVEL to one of the following values:

LV_LOG_LEVEL_TRACE: A lot of logs to give detailed information
LV_LOG_LEVEL_INFO: Log important events
LV_LOG_LEVEL_WARN: Log if something unwanted happened but didn't cause a problem
LV_LOG_LEVEL_ERROR: Only critical issues, where the system may fail
LV_LOG_LEVEL_USER: Only user messages
LV_LOG_LEVEL_NONE: Do not log anything

The events which have a higher level than the set log level will be logged too. E.g. if you LV_LOG_LEVEL_WARN, errors will be also logged.

要启用日志记录，请在 lv_conf.h 中设置 LV_USE_LOG 并将 LV_LOG_LEVEL 设置为以下值之一：

级别高于设置的日志级别的事件也将被记录。例如。如果你 LV_LOG_LEVEL_WARN，错误也将会被记录。

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If your system supports printf, you just need to enable LV_LOG_PRINTF in lv_conf.h to send the logs with printf.

如果你的系统支持 printf，你只需要在 lv_conf.h 中启用 LV_LOG_PRINTF 就可以发送带有 printf 的日志。

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If you can't use printf or want to use a custom function to log, you can register a "logger" callback with lv_log_register_print_cb().

For example:

void my_log_cb(lv_log_level_t level, const char * buf)
{
  serial_send(buf, strlen(buf));
}

...


lv_log_register_print_cb(my_log_cb);

如果你不能使用 printf 或者想使用自定义函数来记录日志，你可以使用 lv_log_register_print_cb() 注册一个“记录器”回调。

例如：

void my_log_cb(lv_log_level_t level, const char * buf)
{
  serial_send(buf, strlen(buf));
}

...


lv_log_register_print_cb(my_log_cb);

显示原文

You can also use the log module via the LV_LOG_TRACE/INFO/WARN/ERROR/USER(text) or LV_LOG(text) functions. Here:

LV_LOG_TRACE/INFO/WARN/ERROR/USER(text) append following information to your text
Log Level
__FILE__
__LINE__
__func__
LV_LOG(text) is similar to LV_LOG_USER but has no extra information attached.

您还可以通过 LV_LOG_TRACE/INFO/WARN/ERROR/USER(text) 和 LV_LOG(text) 函数使用日志模块。这里：

LV_LOG_TRACE/INFO/WARN/ERROR/USER(text) append following information to your text
Log Level（日志级别）
__FILE__（文件名）
__LINE__（行号）
__func__（函数名）
LV_LOG(text) 与 LV_LOG_USER 类似，但没有附加额外信息.