Android的DialogActivity如何实现多选和单选功能

要实现多选和单选功能，可以使用AlertDialog.Builder类来创建一个对话框并设置多选和单选选项。以下是一个示例代码：

AlertDialog.Builder builder = new AlertDialog.Builder(this);builder.setTitle("选择一个选项");final String[] itEMS = {"选项1", "选项2", "选项3"};builder.setSingleChoiceItems(items, -1, new DialogInterface.OnClickListener() {    @Override    public void onClick(DialogInterface dialog, int which) {        // 点击选项时的操作        Toast.makeText(DialogActivity.this, "你选择了：" + items[which], Toast.LENGTH_SHORT).show();        dialog.dismiss();    }});builder.create().show();

AlertDialog.Builder builder = new AlertDialog.Builder(this);builder.setTitle("选择多个选项");final String[] items = {"选项1", "选项2", "选项3"};final boolean[] checkedItems = {false, false, false};builder.setMultiChoiceItems(items, checkedItems, new DialogInterface.OnMultiChoiceClickListener() {    @Override    public void onClick(DialogInterface dialog, int which, boolean isChecked) {        // 多选项点击时的操作        checkedItems[which] = isChecked;    }});builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {    @Override    public void onClick(DialogInterface dialog, int which) {        // 点击确定按钮时的操作        StringBuilder selectedItems = new StringBuilder();        for (int i = 0; i < items.length; i++) {            if (checkedItems[i]) {                selectedItems.append(items[i]).append(" ");            }        }        Toast.makeText(DialogActivity.this, "你选择了：" + selectedItems.toString(), Toast.LENGTH_SHORT).show();        dialog.dismiss();    }});builder.create().show();

通过以上代码示例，可以实现在DialogActivity中实现多选和单选功能。