Question

我正在使用此代码，但它什么也没做：

添加到我的列表视图中：

android:listSelector="@drawable/list_selector"

然后在drawable中使用xml文件来控制不同的状态

@绘制/ list_selector

<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/list_item_bg_normal" android:state_activated="false"/>
<item android:drawable="@drawable/list_item_bg_pressed" android:state_pressed="true"/>
<item android:drawable="@drawable/list_item_bg_pressed" android:state_activated="true"/>
</selector>

@绘制/ list_item_bg_normal

<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<gradient
  android:startColor="#ff0000"
  android:endColor="#ffffff"
  android:angle="90" />
</shape>

@绘制/ list_item_bg_pressed

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
  <gradient
      android:startColor="#ff0000"
      android:endColor="#ffffff"
      android:angle="90" />
</shape>

在活动中：

lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

        view.setSelected(true);

Answer 1

添加

adapter.notifydatasetchanged();

您的代码看起来像这样

lv.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { view.setSelected(true); adapter.notifydatasetchanged();

Answer 2

请更新您的选择器文件，如下所示，并调用通知数据集已更改。在适配器内部，您需要维护一个标志，以便在滚动列表时保持选择。

    <selector xmlns:android="http://schemas.android.com/apk/res/android">

      <item android:drawable="@drawable/list_item_bg_pressed" android:state_pressed="true"/>
      <item android:drawable="@drawable/list_item_bg_pressed" android:state_selected="true"/>
      <item android:drawable="@drawable/list_item_bg_normal"/>
    </selector>

然后

    lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                view.setSelected(true);
                list.get(position).isSelected=true; // list is array items passed to adapter
                adapter.notifydatasetchanged();
            )
    }

在适配器的getView方法中通过使用类似

的布尔值来维护选择

@Override
    public View getView(final int position, View convertView, ViewGroup parent) {
     if(list.get(position).isSelected){
       convertview.setSelected(true)
     }else{
       convertview.setSelected(false)
     }
}

如何更改所选项目的背景颜色？

2 个答案: