Android微调器突出显示所选项目

Question

我有基本的android微调器,我希望在点击它后,列表中包含其中一个突出显示的项目,最初选择的那个.

就像在这里完成的那样:http: //www.warriorpoint.com/blog/wp-content/uploads/2009/05/05spinner-thumb.png

但是我自己的项目布局而不是收音机盒,而是用我自己的背景代替.

我怎样才能做到这一点？选择器中是否有任何用途,或者我是否必须以编程方式执行此操作？

任何帮助表示赞赏.

Answer 1

以下是我测试和验证的解决方案.您可以使用setSelection(N)突出显示所需的项目.

class HighLightArrayAdapter extends ArrayAdapter<CharSequence> {

        private int mSelectedIndex = -1;


        public void setSelection(int position) {
            mSelectedIndex =  position;
            notifyDataSetChanged();
        }

        public HighLightArrayAdapter(Context context, int resource, CharSequence[] objects) {
            super(context, resource, objects);
        }


        @Override
        public View getDropDownView(int position, View convertView, ViewGroup parent) {
            View itemView =  super.getDropDownView(position, convertView, parent);

            if (position == mSelectedIndex) {
                itemView.setBackgroundColor(Color.rgb(56,184,226));
            } else {
                itemView.setBackgroundColor(Color.TRANSPARENT);
            }

            return itemView;
        }
    }

Answer 2

public class MainActivity extends Activity {

Spinner mySpinner;
String[] myArray={"1","2","3","4","5"};
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    mySpinner = (Spinner)findViewById(R.id.spinner_test);

    mySpinner.setAdapter(new MyAdapter(this,android.R.layout.simple_spinner_item, myArray));

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

public class MyAdapter extends ArrayAdapter<String>{

    public MyAdapter(Context context, int textViewResourceId,
            String[] objects) {
        super(context, textViewResourceId, objects);
        // TODO Auto-generated constructor stub
    }

    @Override
    public View getDropDownView(int position, View cnvtView, ViewGroup prnt){
        LayoutInflater inflater = getLayoutInflater();
        View spinnerItem = inflater.inflate(android.R.layout.simple_spinner_item, null);

        TextView mytext= (TextView)spinnerItem.findViewById(android.R.id.text1);
        mytext.setText(myArray[position]);

        //int selected = Spinner.
        int selected = mySpinner.getSelectedItemPosition();
        if(position == selected){
            spinnerItem.setBackgroundColor(Color.BLUE);
        }
        return spinnerItem;

    }

}

}

这应该有所帮助。

Answer 3

要回答我的问题，你需要有这样的东西：

public class mySpinnerAdapter extends SimpleCursorAdapter implements SpinnerAdapter {

public OrderSpinnerAdapter(Context context, int layout, Cursor c, String[] from, int[] to) {
    super(context, layout, c, from, to);
    // TODO whatever you need
}

public View getDropDownView(int position, View convertView, ViewGroup parent) {
    if (convertView == null) {
        convertView = mInflater.inflate(android.R.layout.simple_dropdown_item_1line, parent, false);
    }

    // TODO set the background color of the convertView
    // depending on your wishes

    return convertView;
}
}

这样我们就可以像这样控制下拉列表的创建。如果您需要不同的选择器，您可以在 XML 文件中轻松完成。

然后，当您只需创建适配器并使用 setAdapter 方法将它们绑定到微调器时。