# I need some demos about file I/O

**URL:** <https://discuss.kotlinlang.org/t/i-need-some-demos-about-file-i-o/8556>\
**Category:** Android\
**Created:** [July 13, 2018, 2:28pm UTC](https://discuss.kotlinlang.org/t/i-need-some-demos-about-file-i-o/8556 "2018-07-13T14:28:28Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ehehe](https://avatars.discourse-cdn.com/v4/letter/e/4491bb/32.png) [@ehehe](https://discuss.kotlinlang.org/u/ehehe)\
**Post date:** [July 13, 2018, 2:28pm UTC](https://discuss.kotlinlang.org/t/i-need-some-demos-about-file-i-o/8556/1 "2018-07-13T14:28:28Z")

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I first use kotlin, even first write mobile android App, and have learnt kotlin a few days, but…

I want the app has these features:  
#1 Show files in the specified format as a list.(such as \*.txt).  
#2 Create, write and read files.  
#3 Add items to file.  
#4 Read items from file and show the items on screen as a list.

However I am trapped in dynamically create cardView and add textView. In the internet, many tutorials show create layout by xml, I need to use code.I can’t show textView with specified location in cardView. All textViews start at (0, 0).

Is there a doc like Qt Assistant to introduce every method and have little demo about every widget. I can’t find it. I think it is useful for me to complete this App.

I am a freshman in this field, maybe my statement is too embarrassing and my questions are too easy, I still want anyone can offer me links, demos, etc. I can read and refer them by myself, as you know these materials are so important to a freshman.

Thanks first, very much!!