大彩医用级串口屏Lua应用-文件读写

发布人：大彩科技发布日期：2020-12-31

--get the type and length of the variable
--@data: 'string' or 'table'
--@return: len and type of data
function my_getdataLen_Type(data)

    my_debug_print('---------- my_getdataLen_Type ----------')
    local datalen = -1
    --获取数据类型
    local data_type = type(data)

    --计算数据长度
    if data_type == 'string'
    then
        datalen = string.len(data)
    elseif data_type == 'table'
    then
        datalen = #(data)
    end
    my_debug_print('Lua_debug data Type and Len: '..data_type..' /'..datalen)

    return datalen,data_type
end

--Write data to the end of the file
--@file:file path
--@data:The type of '@data' only be [string] or [byte array]
--@open_mode:open file mode
function my_write_filedata(file, data, open_mode)

    my_debug_print('---------- my_write_filedata ----------')
    my_debug_print('Lua_debug: file -> '..file..' / data -> '..type(data)..' / open_mode -> '..open_mode)
    local count     = 0
    local write_cnt = 0
    local offset    = 0
    local all_byte  = 0
    --获取待写入数据的数据类型和长度
    local wrire_len, data_type = my_getdataLen_Type(data)

    local write_byte_Tb = {}
    local open_state = file_open(file, open_mode)

    if open_state == true
    then
        --获取当前文件大小,仅在追加文件末尾写入执行
        if open_mode == add_write
        then
            all_byte = file_size()
        end

        if wrire_len > 0
        then
            --计算'@data'要写多少次
            write_cnt =  math.modf(wrire_len / WriteOnceSize)
            if wrire_len % WriteOnceSize > 0
            then
                write_cnt = write_cnt + 1
            end
            my_debug_print('Lua_debug: need write allcnt -> '..write_cnt)

            for i = 1, write_cnt
            do
                --复位写字节数组
                write_byte_Tb = {}

                --计算写的位置
                offset = (i - 1) * WriteOnceSize +all_byte
                local offst_result = file_seek(offset)
                --文件偏移失败
                if offst_result == false 
                then
                    set_text(sc_prompt, 1, 'When reading the file, an offset error occurred. please try again! ! !')
                    set_text_roll(sc_prompt, 1, 50)
                    change_child_screen(sc_prompt)
                    break
                end
                my_debug_print('Lua_debug: cur offset  -> '..offset)

                --计算本次写的个数
                count = WriteOnceSize
                if i == write_cnt
                then
                    if wrire_len % WriteOnceSize > 0
                    then
                        count = wrire_len % WriteOnceSize
                    end
                end
                my_debug_print('Lua_debug: cur write  -> '..write_cnt..'th /wrire count '..count)
                --填充写入flash的字节数组
                for j = 1, count 
                do
                    if data_type == 'string'
                    then
                    --字符串类型，将每个字符转换为字节数组
                    write_byte_Tb[j - 1] = tonumber(string.byte(data, ((i - 1) * WriteOnceSize + j), ((i - 1) * WriteOnceSize + j)))

                    elseif data_type == 'table'
                    then
                        --数组类型，字节赋值
                        write_byte_Tb[j - 1] = 
                        data[((i - 1) * WriteOnceSize + j)]
                    end
                end
                local IswriteOK = file_write(write_byte_Tb)
                if IswriteOK == false
                then
                    i = i - 1
                end    
            end
        end
    else
        set_text(sc_prompt, 1, 'The file don`t exist, please check the contents of the SD car! ! !')
        set_text_roll(sc_prompt, 1, 50)
        change_child_screen(sc_prompt)    
    end

    --关闭文件
    file_close()
end

--用户通过触摸修改控件后，执行此回调函数。
--点击按钮控件，修改文本控件、修改滑动条都会触发此事件。
function on_control_notify(screen,control,value)
    ......
    --追加写
    elseif screen == sc_WriteFile and control == 3 and value == 0
then
        sc_ShowRecord = sc_WriteFile
        --已插入SD卡
        if IsinsertSD == 1
        then
            record_clear(sc_WriteFile, 1)

            local str = 'n'..get_text(sc_WriteFile, 2)    
            my_write_filedata(sd_dir..'/'..'1.txt', str, add_write)

            my_read_filedata(sd_dir..'/'..'1.txt')
            local allrecordcnt = record_get_count(sc_WriteFile, 1)
            record_setoffset(sc_WriteFile, 1, allrecordcnt - 1)
            record_select(sc_WriteFile   , 1, allrecordcnt - 1)
        --未插入SD卡
        else
            set_text(sc_prompt, 1, 'Please insert the SD card, or check if the SD is compatible! ! !')
            set_text_roll(sc_prompt, 1, 50)
            change_child_screen(sc_prompt)
        end

    --覆盖写
    elseif screen == sc_WriteFile and control == 5 and value == 0
    then
        sc_ShowRecord = sc_WriteFile
        --已插入SD卡
        if IsinsertSD == 1
        then
            record_clear(sc_WriteFile, 1)

            cnt = cnt + 1
            local str = (cnt + 1)..'th write -> '..get_text(sc_WriteFile, 4) 
            my_write_filedata(sd_dir..'/'..'NewTxtFile.txt',str,over_write)

            my_read_filedata(sd_dir..'/'..'NewTxtFile.txt')
        --未插入SD卡
        else
            set_text(sc_prompt, 1, 'Please insert the SD card, or check if the SD is compatible! ! !')
            set_text_roll(sc_prompt, 1, 50)
            change_child_screen(sc_prompt)
        end
    ......
    end
end