Question

在列表视图中添加新项目时，我想要一个左侧的复选框。我已经尝试了很多，但我没有得到确切的结果。这是代码：

 ListView list;
    Button btn, btn1, btn2, btn3;
    EditText edt;
    CheckBox chk;
    TextView txt;
    StringBuffer buffer = new StringBuffer();
    String[] ListElements = new String[]{
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //find view by ids
        list = (ListView) findViewById(R.id.list);
        btn = (Button) findViewById(R.id.btn);
        btn1 = (Button) findViewById(R.id.btn1);
        btn2 = (Button) findViewById(R.id.btn2);
        btn3 = (Button) findViewById(R.id.btn3);
        edt = (EditText) findViewById(R.id.edt);
        chk = (CheckBox) findViewById(R.id.chk);
        txt = (TextView) findViewById(R.id.txt);
        final List<String> txt = new ArrayList<String>(Arrays.asList(ListElements));

        ArrayList<CheckBox> boxes = new ArrayList<CheckBox>();

        final ArrayAdapter<String> adapter = new ArrayAdapter<String>
                (MainActivity.this, android.R.layout.simple_list_item_1, txt);
        list.setAdapter(adapter);

        //final ListView listView = getListView();

        list.setItemsCanFocus(false);
        list.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                txt.add(edt.getText().toString());
                adapter.notifyDataSetChanged();
            }
        });
    }
}

Answer 1

目前，您正在使用默认的ArrayAdapter作为列表视图。尝试使用自定义适配器 - 这将允许您自定义列表视图布局并在左侧添加一个复选框。

这是example。

或者，像这样：

为layout行创建ListView：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@android:color/holo_blue_light"
            android:padding="10dp">

    <CheckBox
        android:id="@+id/check_box"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <TextView
        android:id="@+id/text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:gravity="center"
        android:text="Dummy Text"
        android:textAllCaps="true"/>

</RelativeLayout>

为ListView行创建模型类：

public class CheckItem {

    private String name;
    private boolean isChecked;

    public CheckItem(String name, boolean isChecked) {
        this.name = name;
        this.isChecked = isChecked;
    }

    public String getName() {
        return name;
    }

    public boolean isChecked() {
        return isChecked;
    }
}

为adapter创建ListView：

public class CheckItemAdapter extends ArrayAdapter<CheckItem> {

    private List<CheckItem> dataSet;

    public CheckItemAdapter(Context context, int resource, List<CheckItem> dataSet) {
        super(context, resource);
        this.dataSet = dataSet;
    }

    @Override 
    public int getCount() {
        return dataSet.size();
    }

    @Override 
    public CheckItem getItem(int position) {
        return dataSet.get(position);
    }

    @Override 
    public long getItemId(int position) {
        return position;
    }

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

        ViewHolder holder;

        if (convertView == null) {

            // Inflate layout
            convertView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.adapter, parent, false);

            // Setup ViewHolder
            holder = new ViewHolder();
            holder.checkBox = (CheckBox) convertView.findViewById(R.id.check_box);
            holder.textView = (TextView) convertView.findViewById(R.id.text_view);

            // Store ViewHolder with this row view
            convertView.setTag(holder);

        } else {

            // Use viewHolder - quicker than calling findViewById() on resource every time
            holder = (ViewHolder) convertView.getTag();
        }

        // Get item from your data set at the current list position
        CheckItem checkItem = getItem(position);

        if (checkItem != null) {
            // Set the views to match the item from your data set
            holder.checkBox.setChecked(checkItem.isChecked());
            holder.textView.setText(checkItem.getName());
         }

         return convertView;
    }

    // ViewHolder acts as a cache for row views
    private class ViewHolder {
        TextView textView;
        CheckBox checkBox;
    }
}

在adapter中将ListView设为Activity：

@Override 
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.your_activity_layout);

    ...

    List<CheckItem> checkItems = new ArrayList<>();

    // Provide adapter with dummy data for testing
    for (int i = 0; i < 50; i++) {
        checkItems.add(new CheckItem("Check Item " + (i + 1), i % 2 == 0));
    }

    CheckItemAdapter adapter = new CheckItemAdapter(this, R.layout.adapter, checkItems);
    ListView listView = (ListView) findViewById(R.id.list_view);

    listView.setAdapter(adapter);
}

在listview中添加新项目时，我想要一个带有它的复选框

1 个答案: