带有多项选择的 Android Spinner [英] Android Spinner with multiple choice

问题描述

如何创建允许选择多个项目的微调器，即带有复选框的微调器?

How do I create spinner which allows to choose multiple items, i.e spinner with check boxes?

推荐答案

我已经编写了 MultiSpinner 的自定义实现.它看起来类似于普通的微调器，但它有复选框而不是单选按钮.选定的值显示在微调器上，以逗号分隔.默认情况下检查所有值.试试看:

I have written custom implementation of MultiSpinner. It's looking similar to normal spinner, but it has checkboxes instead of radiobuttons. Selected values are displayed on the spinner divided by comma. All values are checked by default. Try it:

package cz.destil.settleup.gui;

public class MultiSpinner extends Spinner implements
        OnMultiChoiceClickListener, OnCancelListener {

    private List<String> items;
    private boolean[] selected;
    private String defaultText;
    private MultiSpinnerListener listener;

    public MultiSpinner(Context context) {
        super(context);
    }

    public MultiSpinner(Context arg0, AttributeSet arg1) {
        super(arg0, arg1);
    }

    public MultiSpinner(Context arg0, AttributeSet arg1, int arg2) {
        super(arg0, arg1, arg2);
    }

    @Override
    public void onClick(DialogInterface dialog, int which, boolean isChecked) {
        if (isChecked)
            selected[which] = true;
        else
            selected[which] = false;
    }

    @Override
    public void onCancel(DialogInterface dialog) {
        // refresh text on spinner
        StringBuffer spinnerBuffer = new StringBuffer();
        boolean someSelected = false;
        for (int i = 0; i < items.size(); i++) {
            if (selected[i] == true) {
                spinnerBuffer.append(items.get(i));
                spinnerBuffer.append(", ");
                someSelected = true;
            } 
        }
        String spinnerText;
        if (someSelected) {
            spinnerText = spinnerBuffer.toString();
            if (spinnerText.length() > 2)
                spinnerText = spinnerText.substring(0, spinnerText.length() - 2);
        } else {
            spinnerText = defaultText;
        }
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(getContext(),
                android.R.layout.simple_spinner_item,
                new String[] { spinnerText });
        setAdapter(adapter);
        listener.onItemsSelected(selected);
    }

    @Override
    public boolean performClick() {
        AlertDialog.Builder builder = new AlertDialog.Builder(getContext());
        builder.setMultiChoiceItems(
                items.toArray(new CharSequence[items.size()]), selected, this);
        builder.setPositiveButton(android.R.string.ok,
                new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.cancel();
                    }
                });
        builder.setOnCancelListener(this);
        builder.show();
        return true;
    }

    public void setItems(List<String> items, String allText,
            MultiSpinnerListener listener) {
        this.items = items;
        this.defaultText = allText;
        this.listener = listener;

        // all selected by default
        selected = new boolean[items.size()];
        for (int i = 0; i < selected.length; i++)
            selected[i] = true;

        // all text on the spinner
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(getContext(),
                android.R.layout.simple_spinner_item, new String[] { allText });
        setAdapter(adapter);
    }

    public interface MultiSpinnerListener {
        public void onItemsSelected(boolean[] selected);
    }
}

您可以像这样在 XML 中使用它:

You use it in XML like this:

<cz.destil.settleup.gui.MultiSpinner android:id="@+id/multi_spinner" />

然后你像这样用 Java 将数据传递给它:

And you pass data to it in Java like this:

MultiSpinner multiSpinner = (MultiSpinner) findViewById(R.id.multi_spinner);
multiSpinner.setItems(items, getString(R.string.for_all), this);

还需要实现监听器，它将返回相同长度的数组，用真或假来显示选择到未选择..

Also you need to implement the listener,which will return the same length array , with true or false to show selected to unselected..

public void onItemsSelected(boolean[] selected);

这篇关于带有多项选择的 Android Spinner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！