在滚动微调器之前，Android Spinner 单选按钮视图不会响应答案

【问题标题】：Android Spinner Radiobutton view doesn't respond until you scroll the spinner在滚动微调器之前，Android Spinner 单选按钮视图不会响应
【发布时间】：2013-11-15 09:31:06
【问题描述】：

我在一个屏幕上有一个微调器，设置如下：

    defScreenSpinner = (Spinner) v.findViewById(R.id.default_screen);
adapter =
  new SimpleAdapter(v.getContext(), data, R.layout.image_spinner_item, new String[] { "image" },
    new int[] { R.id.image }) {
    private View[] views = new View[data.size()];

    @Override
    public View getDropDownView(int position, View convertView, ViewGroup parent) {
      Log.d(TAG, "getDropDownView: " + position);
      View v = views[position];

      if (v == null) {
        // Need unique views so Radio buttons can be tracked individually
        v = inflater.inflate(R.layout.image_spinner_item, null);

        Map<String, Object> map = data.get(position);
        int imgresid = (Integer) map.get("image");
        boolean selected = (position == defScreenIdx);
        Log.d(TAG,
              String.format("populateView: position=%d, resid=%d, sel=%d", position, imgresid, (selected ? 1 : 0)));
        ImageView iv = (ImageView) v.findViewById(R.id.image);
        iv.setImageResource(imgresid);
        RadioButton cb = (RadioButton) v.findViewById(R.id.selectedimg);
        cb.setChecked(selected);
        cb.setTag(position);
        if (selected) {
          curButton = cb;
        }
        cb.setOnCheckedChangeListener(new OnCheckedChangeListener() {
          @Override
          public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            Log.d(TAG, "Button Clicked: " + isChecked);
            if (buttonView.isChecked()) {
              onSelDefault(buttonView);
            }
          }
        });

        v.setOnClickListener(new View.OnClickListener() {

          @Override
          public void onClick(View v) {
            Log.d(TAG, "View Clicked: ");
          }
        });

        views[position] = v;
      }

      return v;
    }
  };
defScreenSpinner.setAdapter(adapter);
defScreenSpinner.setBackgroundResource(imgIds.get(defScreenIdx));
defScreenSpinner.setSelection(defScreenIdx);

...

  public void onSelDefault(View v) {
    if (curButton != null) {
      curButton.setChecked(false);
      curButton.invalidate();
    }
    curButton = (RadioButton) v;
    curButton.setChecked(true);
    defScreenIdx = (Integer) v.getTag();
    Log.d(TAG, "defIdx=" + defScreenIdx);
    defScreenSpinner.setBackgroundResource(imgIds.get(defScreenIdx));
    defScreenSpinner.setSelection(defScreenIdx);
    return;
    }

微调器按钮看起来不错，当您单击微调器面板时会出现。问题是单选按钮根本不起作用 - 直到您滚动视图。当我第一次单击 Spinner 按钮时，日志显示如下：

11-04 08:42:04.831: D/PreferencesActivity(6236): getDropDownView: 0
11-04 08:42:04.831: D/PreferencesActivity(6236): populateView: position=0, resid=2130837697, sel=1
11-04 08:42:04.831: D/PreferencesActivity(6236): getDropDownView: 1
11-04 08:42:04.841: D/PreferencesActivity(6236): populateView: position=1, resid=2130837715, sel=0
11-04 08:42:04.841: D/PreferencesActivity(6236): getDropDownView: 2
11-04 08:42:04.841: D/PreferencesActivity(6236): populateView: position=2, resid=2130837725, sel=0
11-04 08:42:04.841: D/PreferencesActivity(6236): getDropDownView: 3
11-04 08:42:04.851: D/PreferencesActivity(6236): populateView: position=3, resid=2130837640, sel=0
11-04 08:42:04.851: D/PreferencesActivity(6236): getDropDownView: 4
11-04 08:42:04.851: D/PreferencesActivity(6236): populateView: position=4, resid=2130837721, sel=0
11-04 08:42:04.851: D/PreferencesActivity(6236): getDropDownView: 5
11-04 08:42:04.862: D/PreferencesActivity(6236): populateView: position=5, resid=2130837513, sel=0
11-04 08:42:04.862: D/PreferencesActivity(6236): getDropDownView: 6
11-04 08:42:04.862: D/PreferencesActivity(6236): populateView: position=6, resid=2130837507, sel=0
11-04 08:42:04.881: D/PreferencesActivity(6236): getDropDownView: 0
11-04 08:42:04.881: D/PreferencesActivity(6236): getDropDownView: 1
11-04 08:42:04.881: D/PreferencesActivity(6236): getDropDownView: 2
11-04 08:42:04.881: D/PreferencesActivity(6236): getDropDownView: 3
11-04 08:42:04.891: D/PreferencesActivity(6236): getDropDownView: 4
11-04 08:42:04.891: D/PreferencesActivity(6236): getDropDownView: 5
11-04 08:42:04.891: D/PreferencesActivity(6236): getDropDownView: 6
11-04 08:42:04.891: D/PreferencesActivity(6236): getDropDownView: 0
11-04 08:42:04.891: D/PreferencesActivity(6236): getDropDownView: 1
11-04 08:42:04.891: D/PreferencesActivity(6236): getDropDownView: 2
11-04 08:42:04.891: D/PreferencesActivity(6236): getDropDownView: 3
11-04 08:42:04.891: D/PreferencesActivity(6236): getDropDownView: 4
11-04 08:42:04.891: D/PreferencesActivity(6236): getDropDownView: 5
11-04 08:42:04.901: D/PreferencesActivity(6236): getDropDownView: 0
11-04 08:42:04.901: D/PreferencesActivity(6236): getDropDownView: 1
11-04 08:42:04.901: D/PreferencesActivity(6236): getDropDownView: 2
11-04 08:42:04.901: D/PreferencesActivity(6236): getDropDownView: 3
11-04 08:42:04.911: D/PreferencesActivity(6236): getDropDownView: 4
11-04 08:42:04.911: D/PreferencesActivity(6236): getDropDownView: 5
11-04 08:42:04.911: D/PreferencesActivity(6236): getDropDownView: 6
11-04 08:42:04.921: D/PreferencesActivity(6236): getDropDownView: 0
11-04 08:42:04.921: D/PreferencesActivity(6236): getDropDownView: 1
11-04 08:42:04.921: D/PreferencesActivity(6236): getDropDownView: 2
11-04 08:42:04.931: D/PreferencesActivity(6236): getDropDownView: 3
11-04 08:42:04.931: D/PreferencesActivity(6236): getDropDownView: 4
11-04 08:42:04.931: D/PreferencesActivity(6236): getDropDownView: 5
11-04 08:42:04.931: D/PreferencesActivity(6236): getDropDownView: 6
11-04 08:42:13.646: D/PreferencesActivity(6236): getDropDownView: 6

因此，它构建了前 7 个单选按钮，并选择了第一个。所以我然后单击按钮 2 到 4。日志中没有显示任何内容。接下来，我将视图一直向下滚动并返回到顶部。日志显示：

11-04 09:09:52.662: D/PreferencesActivity(6262): getDropDownView: 6
11-04 09:09:52.662: D/PreferencesActivity(6262): getDropDownView: 7
11-04 09:09:52.671: D/PreferencesActivity(6262): populateView: position=7, resid=2130837707, sel=0
11-04 09:09:52.701: D/PreferencesActivity(6262): getDropDownView: 8
11-04 09:09:52.701: D/PreferencesActivity(6262): populateView: position=8, resid=2130837709, sel=0
11-04 09:09:52.701: D/PreferencesActivity(6262): getDropDownView: 9
11-04 09:09:52.721: D/PreferencesActivity(6262): populateView: position=9, resid=2130837653, sel=0
11-04 09:09:52.721: D/PreferencesActivity(6262): getDropDownView: 10
11-04 09:09:52.721: D/PreferencesActivity(6262): populateView: position=10, resid=2130837705, sel=0
11-04 09:09:52.721: D/PreferencesActivity(6262): getDropDownView: 11
11-04 09:09:52.732: D/PreferencesActivity(6262): populateView: position=11, resid=2130837651, sel=0
11-04 09:09:52.912: D/PreferencesActivity(6262): getDropDownView: 12
11-04 09:09:52.912: D/PreferencesActivity(6262): populateView: position=12, resid=2130837514, sel=0
11-04 09:09:52.932: D/PreferencesActivity(6262): getDropDownView: 13
11-04 09:09:52.932: D/PreferencesActivity(6262): populateView: position=13, resid=2130837677, sel=0
11-04 09:09:52.942: D/PreferencesActivity(6262): getDropDownView: 14
11-04 09:09:52.961: D/PreferencesActivity(6262): populateView: position=14, resid=2130837717, sel=0
11-04 09:09:53.042: D/PreferencesActivity(6262): getDropDownView: 15
11-04 09:09:53.042: D/PreferencesActivity(6262): populateView: position=15, resid=2130837593, sel=0
11-04 09:09:53.072: D/PreferencesActivity(6262): getDropDownView: 16
11-04 09:09:53.072: D/PreferencesActivity(6262): populateView: position=16, resid=2130837689, sel=0
11-04 09:09:53.082: D/PreferencesActivity(6262): getDropDownView: 17
11-04 09:09:53.092: D/PreferencesActivity(6262): populateView: position=17, resid=2130837712, sel=0
11-04 09:09:53.092: D/PreferencesActivity(6262): getDropDownView: 13
11-04 09:09:53.092: D/PreferencesActivity(6262): getDropDownView: 12
11-04 09:09:54.762: D/PreferencesActivity(6262): getDropDownView: 11
11-04 09:09:54.802: D/PreferencesActivity(6262): getDropDownView: 10
11-04 09:09:54.862: D/PreferencesActivity(6262): getDropDownView: 9
11-04 09:09:54.862: D/PreferencesActivity(6262): getDropDownView: 8
11-04 09:09:54.872: D/PreferencesActivity(6262): getDropDownView: 7
11-04 09:09:54.952: D/PreferencesActivity(6262): getDropDownView: 6
11-04 09:09:54.952: D/PreferencesActivity(6262): getDropDownView: 5
11-04 09:09:54.952: D/PreferencesActivity(6262): getDropDownView: 4
11-04 09:09:55.092: D/PreferencesActivity(6262): getDropDownView: 3
11-04 09:09:55.092: D/PreferencesActivity(6262): getDropDownView: 2
11-04 09:09:55.111: D/PreferencesActivity(6262): getDropDownView: 1
11-04 09:09:55.111: D/PreferencesActivity(6262): getDropDownView: 0
11-04 09:09:55.111: D/PreferencesActivity(6262): getDropDownView: 5

单击第二个按钮会导致这些日志条目：（看来我之前的点击都在排队等待某事......）

11-04 09:10:56.248: D/PreferencesActivity(6262): Button Clicked: true
11-04 09:10:56.248: D/PreferencesActivity(6262): Button Clicked: false
11-04 09:10:56.252: D/PreferencesActivity(6262): defIdx=1
11-04 09:10:56.325: D/PreferencesActivity(6262): Button Clicked: true
11-04 09:10:56.325: D/PreferencesActivity(6262): Button Clicked: false
11-04 09:10:56.325: D/PreferencesActivity(6262): defIdx=2
11-04 09:10:56.332: D/PreferencesActivity(6262): Button Clicked: true
11-04 09:10:56.332: D/PreferencesActivity(6262): Button Clicked: false
11-04 09:10:56.332: D/PreferencesActivity(6262): defIdx=3
11-04 09:10:56.352: D/PreferencesActivity(6262): Button Clicked: true
11-04 09:10:56.352: D/PreferencesActivity(6262): Button Clicked: false
11-04 09:10:56.352: D/PreferencesActivity(6262): defIdx=4

现在第 5 个按钮 (idx = 4) 已被选中。

从现在开始，点击任何按钮都可以正常工作。按钮被选中，旧按钮被取消选中。

我该如何进行这项工作？

【问题讨论】：

标签： android radio-button spinner

【解决方案1】：

您正在缓存Views。不要那样做。微调器本身会回收Views，因此您对它们的缓存会产生冲突。您需要查看Android中常用的ViewHolder模式，并了解如何正确使用回收的View（convertView参数）。

【讨论】：

是的。甚至没有注意到它正在这样做。（我继承的旧代码。bleh。）一旦我开始正确使用 convertView，困难的部分是让旧的 Radio Button 取消选中。最终使用 adapter.notifyDataSetChanged 来更新列表。