OnItemChangd怎么用
时间: 2023-10-24 12:21:16 浏览: 28
OnItemChanged是一个事件,它在ListView、GridView、Spinner等控件中,当列表项被选中时触发。在使用OnItemChanged时,需要实现OnItemSelectedListener接口,并重写onItemSelected和onNothingSelected两个方法,然后将其设置给控件。
以下是OnItemChanged的使用示例:
1. 实现OnItemSelectedListener接口
```java
public class MyItemSelectedListener implements AdapterView.OnItemSelectedListener{
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
// 当某个项被选中时触发
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
// 当没有选中任何项时触发
}
}
```
2. 将OnItemSelectedListener设置给控件
```java
Spinner spinner = findViewById(R.id.spinner);
spinner.setOnItemSelectedListener(new MyItemSelectedListener());
```
在上述示例中,我们将MyItemSelectedListener设置给了Spinner控件,当选中某个项时,会触发onItemSelected方法。如果没有选中任何项,则会触发onNothingSelected方法。类似地,我们也可以将OnItemSelectedListener设置给ListView、GridView等控件。
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