Spinner.getItemAtPosition(...)返回哪种类型的对象? [英] What type of Object does Spinner.getItemAtPosition(...) return?

问题描述

此语句将返回什么?

parent.getItemAtPosition(position)

parent是微调器的父视图，而position是从微调器视图中选择的位置.

Where parent is a parent view for a spinner and position is the selected position from the spinner view.

推荐答案

我假设您正在谈论的父母"是Spinner.在这种情况下:

I assume the "parent" you are talking about is a Spinner. In this case:

Spinner.getItemAtPosition(pos); 

将始终返回填充了Spinner的对象的类型.

使用CustomType的示例:(微调器中填充了"CustomType"类型的项目，因此getItemAtPosition(...)将返回CustomType)

An example using a CustomType: (the Spinner is filled with Items of type "CustomType", therefore getItemAtPosition(...) will return CustomType)

Spinner spinner = (Spinner) findViewById(R.id.spinner1);
CustomType [] customArray = new CustomType[] { .... your custom items here .... };

// fill an arrayadapter and set it to the spinner
ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_spinner_item, customArray);

spinner.setAdapter(adapter);  

CustomType type = (CustomType) spinner.getItemAtPosition(0); // it will return your CustomType so you can safely cast to it

另一个使用字符串数组的示例:(微调器中填充了字符串"类型的项目，因此getItemAtPosition(...)将返回字符串)

Another example using a String Array: (the Spinner is filled with Items of type "String", therefore getItemAtPosition(...) will return String)

Spinner spinner = (Spinner) findViewById(R.id.spinner1);
String[] stringArray= new String[] { "A", "B", "C" };

// fill an arrayadapter and set it to the spinner
ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_spinner_item, stringArray);

spinner.setAdapter(adapter);  

String item = (String ) spinner.getItemAtPosition(0); // it will return your String so you can safely cast to it

这篇关于Spinner.getItemAtPosition(...)返回哪种类型的对象?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！