Question

我正在为listview构建一个自定义适配器 - 我希望这个适配器能够为listview提供交替的背景颜色。

boolean alternate = false;

@Override
public View getView(int position, View convertView, ViewGroup parent) {

        if (alternate)
        {
            // set background colour of this item?
        }

        alternate = !alternate;

        // lots of other stuff here

        return convertView;     }

如何在上下文中设置listview项的背景？

Answer 1

Alternate List item background

以下是要执行的步骤。步骤1.1）对奇数和偶数位置列表项使用两个选择器

artists_list_backgroundcolor.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
 <item
 android:state_selected="false"
    android:state_pressed="false"
    android:drawable="@color/grey" />
<item android:state_pressed="true"
    android:drawable="@color/itemselected" />
<item android:state_selected="true"
 android:state_pressed="false"
    android:drawable="@color/itemselected" />
</selector>

步骤1.2） artists_list_background_alternate.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
 <item
 android:state_selected="false"
    android:state_pressed="false"
    android:drawable="@color/sign_out_color" />
<item android:state_pressed="true"
    android:drawable="@color/login_hover" />
<item android:state_selected="true"
 android:state_pressed="false"
    android:drawable="@color/login_hover" />
</selector>

步骤2） colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <color name="survey_toplist_item">#EFEDEC</color>
    <color name="survey_alternate_color">#EBE7E6</color>
    <color name="grey">#ffffff</color>
    <color name="itemselected">#EDEDED</color>
    <color name="login_hover">#E5F5FA</color>
    <color name="sign_out_color">#e84040</color>

</resources>

步骤3）在Arrayadapter中：

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View view = convertView;
        if (view == null) {
            view = lInflater.inflate(R.layout.listitem, parent, false);
        }

        if (position % 2 == 0) {
            view.setBackgroundResource(R.drawable.artists_list_backgroundcolor);
        } else {
            view.setBackgroundResource(R.drawable.artists_list_background_alternate);
        }

        ((TextView) view.findViewById(R.id.heading)).setText(data.get(position));

        return view;
    }

有关详情，请浏览belog链接

http://amitandroid.blogspot.in/2013/03/android-listview-with-alternate-list.html

Answer 2

你没有朝着正确的方向前进，就像重新使用这些视图一样，你可能会得到意想不到的结果，因为有些回收的视图会有不同的颜色，而有些则没有。

而不是上面，根据位置设置背景。类似的东西：

if(position % 2 == 0) {
    // set some color
} else {
    // set the other color
}

Answer 3

您可以使用此代码：

 if (position % 2 == 0) {
            holder.image.setBackgroundResource(R.drawable.image1);
        } else {
           holder.image.setBackgroundResource(R.drawable.image2);
        }

Answer 4

如果我错了，请纠正我，但我是这样做的：

@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
        convertView = ((LayoutInflater) this._ctx
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE))
                .inflate(this._resource, parent, false);

    }

   switch(position % 3){
      case 0: convertView.setBackgroun....
          break;
      .... (case 1; case 2;)

   }

return convertView;

}

Answer 5

您可以在适配器中执行

   public View getView(int position, View convertView, ViewGroup parent) {

        if (convertView == null) {
            inflater = ((Activity) context).getLayoutInflater();
            convertView = inflater.inflate(resourceId, parent, false);
        }
       Person user = getItem(position);

       if(user.isCharged)
       convertView.setBackgroundColor(Color.BLUE);
    }

将在您的所有项目中应用

Answer 6

我想强调解决方案，以免引起人们的困惑。

如果需要颜色/图像，或在绘制时对列表视图进行任何更改，则需要在getView中进行设置，如下所示，但是如果要使其在单击时显示，则需要使用onClick方法如下所示。

    @Override
    public View getView(int position, View view, ViewGroup parent) {
        if(view == null) {
            view = inflater.inflate(R.layout.dashboard_item, parent, false);
        }

        if(selected[position]) {
            view.setBackgroundColor(Color.LTGRAY);
        } else {
            selected[position] = false;
            view.setBackgroundColor(Color.WHITE);
        }
        return view;
    }

    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            //this is just my custom object..you could also assign your boolean here to see if it is "highlighted"
            Item o = (Item)listView.getItemAtPosition(position);
            if(adapter.selected[position] == true) {
                adapter.selected[position] = false;
                view.setBackgroundColor(Color.WHITE);
            } else {
                adapter.selected[position] = true;
                view.setBackgroundColor(Color.LTGRAY);
            }
     }

我的布尔检查只是一个布尔数组，如

private boolean[] selected;

我在ArrayAdapater构造函数的子类中将其初始化。

selected = new boolean[objects.size()];
Arrays.fill(selected, Boolean.FALSE);

在适配器getView方法中更改当前listview项的背景颜色

6 个答案: