android - 如何在 ListView 中正确更改特定行的背景颜色？ (安卓)

Question

我花了几天时间尝试解决我在 Android 上使用 ListView 时遇到的问题。我想使用 ListView 实现单个选择列表框。因此，我希望只有一行具有预定义的浅色背景颜色，其余行具有另一种预选颜色。我遇到的问题是，当我单击特定行时，是突出显示的另一行而不是我按下的行。我添加了几条消息来记录正在发生的事情，但似乎一切正常。这是我的代码:

public class TryListViewActivity extends Activity {
    protected static final int NO_SELECTED_COLOR = 0xFF191919;
    protected static final int SELECTED_COLOR = 0xFF3366CC;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        ListView listView = new ListView(this);
        ArrayList<String> list = new ArrayList<String>();
        list.add("Option 1");
        list.add("Option 2");
        list.add("Option 3");
        list.add("Option 4");
        list.add("Option 5");
        list.add("Option 6");
        list.add("Option 7");
        list.add("Option 8");
        list.add("Option 9");
        list.add("Option 10");
        list.add("Option 11");
        list.add("Option 12");
        list.add("Option 13");
        list.add("Option 14");
        list.add("Option 15");

        ArrayAdapter<String> listAdapter = new ArrayAdapter<String>(
            this,
            R.layout.list_box_entry,
            list
        );
        listView.setAdapter(listAdapter);

        listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);

        // Set the listener
        listView.setOnItemClickListener(
            new AdapterView.OnItemClickListener() {
                public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                    Log.i(
                        "Log",
                        "[SingleSelectionListBox] Item clicked: position="
                        + position + ";id=" + id
                    );

                    // First, set all rows to be unselected
                    int counter  = parent.getCount();
                    Log.i(
                        "Log",
                        "[SingleSelectionListBox] "
                        + counter + " items found inside the parent"
                    );
                    int children = parent.getChildCount();
                    Log.i(
                        "Log",
                        "[SingleSelectionListBox] "
                        + children + " views found inside the parent"
                    );
                    for(int i=0;i<children;i++) {
                        Log.i(
                            "Log",
                            "[SingleSelectionListBox] Child "
                            + i + " has message "
                            + ((TextView)parent.getChildAt(i)).getText()
                        );
                    }

                    // Too inefficient but for now is OK
                    for(int i=0;i<children;i++)
                        parent.getChildAt(i)
                            .setBackgroundColor(NO_SELECTED_COLOR);
                    Log.i("Log",
                        "[SingleSelectionListBox] First visible position: "
                        + parent.getFirstVisiblePosition()
                    );

                    // Set the background color
                    TextView textView = (TextView)(parent.getChildAt(
                        position-parent.getFirstVisiblePosition()));
                    textView.setBackgroundColor(SELECTED_COLOR);
                    Log.i(
                        "Log",
                        "[SingleSelectionListBox] Text inside the "
                        + " View changing the color " + textView.getText()
                    );
                }
            }
        );
        setContentView(listView);
    }
}

在资源(资源/布局)中，我插入了一个名为 list_text_entry.xml 的文件，内容如下

<TextView xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent"
  android:layout_height="fill_parent" android:gravity="center"
  android:textColor="#FFFFFF" android:padding="10dp" android:textSize="16sp">
</TextView>

例如，如果我在 listView 之前向下滚动直到我看到的第一行是“选项 4”时单击“选项 11”条目，则“选项 7”行显示为已选中，是唯一携带的行背景中的蓝色。有人可以向我解释这里发生的事情吗？我将收到的消息发布在日志下方。

[SingleSelectionListBox] Item clicked: position=10;id=10
[SingleSelectionListBox] 15 items found inside the parent
[SingleSelectionListBox] 11 views found inside the parent
[SingleSelectionListBox] Child 0 has message Option 4
[SingleSelectionListBox] Child 1 has message Option 5
[SingleSelectionListBox] Child 2 has message Option 6
[SingleSelectionListBox] Child 3 has message Option 7
[SingleSelectionListBox] Child 4 has message Option 8
[SingleSelectionListBox] Child 5 has message Option 9
[SingleSelectionListBox] Child 6 has message Option 10
[SingleSelectionListBox] Child 7 has message Option 11
[SingleSelectionListBox] Child 8 has message Option 12
[SingleSelectionListBox] Child 9 has message Option 13
[SingleSelectionListBox] Child 10 has message Option 14
[SingleSelectionListBox] First visible position: 3
[SingleSelectionListBox] Text inside the View changing the color Option 11

因为我可以猜测 ViewGroup 中的所有子项都是从上到下排序的，即使我在代码中这样做也是如此:

TextView textView = (TextView)(parent.getChildAt(
    position-parent.getFirstVisiblePosition()
));
textView.setBackgroundColor(SELECTED_COLOR);

出现消息 Option 11 但实际上是选择了 option 7。这是 Android 的错误吗？

Answer 1

我已经使用了这段代码，它运行良好，你应该试试这个:

listView.getChildAt(0).setBackgroundColor(Color.BLUE);