ListView android xamarin中的数据随机播放
我正在使用android xamarin中的listview。我用webview，radiogroup和3个单选按钮创建了一个自定义控件。我有一个html字符串，它被拆分以创建一个问题数组，并传递给适配器。它们将它们绑定到ListView，如屏幕截图所示。
问题是每当我滚动屏幕时，数据都会混乱，行会混乱。假设我有5个问题，按顺序A，B，C，D，E - 它可以随机变成D，B，C，D，E或E，B，C，D，E或A B E D C.不确定为什么这应该发生。尝试了一些事情，但它只是赢了工作。
我正在使用片段作为屏幕，因为我还有其他屏幕更新数据对象，后来提交给服务器。
我确信Adapter类中的代码有问题，但无法弄清楚。这是代码（**注释代码是我尝试过的旧代码。）
更新了GetView代码
public override View GetView (int position, View convertView, ViewGroup parent)
{
//var view = convertView ?? _activity.Activity.LayoutInflater.Inflate (Resource.Layout.SegmentedControl, parent, false);
View view = convertView;
ViewHolder holder = null;
Utils.WriteDebugInfo ("position - " + position + " dsadsadsadad - " + _questionList [position]);
//if (view == null) {
/*if (view != null) {
view = null;
}*/
view = _activity.Activity.LayoutInflater.Inflate (Resource.Layout.SegmentedControl, parent, false);
holder = new ViewHolder ();
holder.WebViewQuestion = view.FindViewById<WebView> (Resource.Id.segmentControlQuestionTextView);
//holder.RadioGroupToUse = view.FindViewById<RadioGroup> (Resource.Id.segmentControlRadioGroupLayout);
holder.RadioButton1 = view.FindViewById<Button> (Resource.Id.segmentControlRadio1);
holder.RadioButton2 = view.FindViewById<Button> (Resource.Id.segmentControlRadio2);
holder.RadioButton3 = view.FindViewById<Button> (Resource.Id.segmentControlRadio3);
//holder.RadioButton1.CheckedChange += ((object sender, CompoundButton.CheckedChangeEventArgs e) => {
holder.RadioButton1.Click += ((object sender, EventArgs e) => {
//if ((sender as RadioButton).Checked) {
//Utils.WriteDebugInfo ("Choice is : A ==== " + _questionArr [position]);
_activity.Activity.RunOnUiThread (() => {
holder.RadioButton2.SetBackgroundResource (0);
holder.RadioButton2.SetBackgroundColor (new Android.Graphics.Color(255,255,0,255));
holder.RadioButton3.SetBackgroundResource (0);
holder.RadioButton3.SetBackgroundColor (new Android.Graphics.Color(255,0,0,255));
//(sender as Button).SetBackgroundColor(Android.Graphics.Color.LimeGreen);
(sender as Button).SetBackgroundResource (Resource.Drawable.GreenButton_BlackBorder);
});
Utils.WriteDebugInfo ("Choice is : A ==== " + _questionList [position].QuestionText);
UpdateFeedback2Answer3String (position, 0, false);
//}
});
//holder.RadioButton2.CheckedChange += ((object sender, CompoundButton.CheckedChangeEventArgs e) => {
holder.RadioButton2.Click += ((object sender, EventArgs e) => {
//if ((sender as RadioButton).Checked) {
//Utils.WriteDebugInfo ("Choice is : B === " + _questionArr [position]);
_activity.Activity.RunOnUiThread (() => {
holder.RadioButton1.SetBackgroundResource (0);
holder.RadioButton1.SetBackgroundColor (new Android.Graphics.Color(0,255,0,255));
holder.RadioButton3.SetBackgroundResource (0);
holder.RadioButton3.SetBackgroundColor (new Android.Graphics.Color(255,0,0,255));
//(sender as Button).SetBackgroundColor(Android.Graphics.Color.Yellow);
(sender as Button).SetBackgroundResource (Resource.Drawable.YellowButton_BlackBorder);
});
Utils.WriteDebugInfo ("Choice is : A ==== " + _questionList [position].QuestionText);
UpdateFeedback2Answer3String (position, 1, false);
//}
});
//holder.RadioButton3.Click += ((object sender, CompoundButton.CheckedChangeEventArgs e) => {
holder.RadioButton3.Click += ((object sender, EventArgs e) => {
//if ((sender as RadioButton).Checked) {
//Utils.WriteDebugInfo ("Choice is : C === " + _questionArr [position]);
_activity.Activity.RunOnUiThread (() => {
holder.RadioButton1.SetBackgroundResource (0);
holder.RadioButton1.SetBackgroundColor (new Android.Graphics.Color(0,255,0,255));
holder.RadioButton2.SetBackgroundResource (0);
holder.RadioButton2.SetBackgroundColor (new Android.Graphics.Color(255,255,0,255));
//(sender as Button).SetBackgroundColor(Android.Graphics.Color.Red);
(sender as Button).SetBackgroundResource (Resource.Drawable.RedButton_BlackBorder);
});
Utils.WriteDebugInfo ("Choice is : A ==== " + _questionList [position].QuestionText);
UpdateFeedback2Answer3String (position, 2, false);
//}
});
view.Tag = holder;
//segmentControlQuestionTextView = view.FindViewById<WebView> (Resource.Id.segmentControlQuestionTextView);
/*} else {
view = convertView;
holder = view.Tag as ViewHolder;
}*/
string html_string;
html_string = "<html>" +
"<head>" +
"</head>" +
"<body style='background-color: #50b983'>" +
"<font face='ProximaNova_Regular' size='4' color='white'>{text}</font> " +
"</body>" +
"</html>";
//html_string = html_string.Replace ("{text}", _questionArr [position]);
Utils.WriteDebugInfo ("Current View : " + position);
html_string = html_string.Replace ("{text}", _questionList [position].QuestionText);
holder.WebViewQuestion.LoadData (html_string, "text/html; charset=UTF-8", null);
string feedback2Question3Answer = string.Empty;
if (ChallengeFeedbackActivity.ReviewState) {
if (ChallengeFeedbackActivity.FeedbackToReview != null && ChallengeFeedbackActivity.FeedbackToReview != null) {
//SetFragmentData (ChallengeFeedbackActivity.FeedbackToReview.UserChallengeFeedbackResponse.Feedback2Question3Answer, position);
feedback2Question3Answer = ChallengeFeedbackActivity.FeedbackToReview.UserChallengeFeedbackResponse.Feedback2Question3Answer;
}
} else {
if (AppData.Instance.FeedbackSubmissionData != null) {
feedback2Question3Answer = Utils.IsStringNullOrEmptyOrWhiteSpace(AppData.Instance.FeedbackSubmissionData.Feedback2Question3Answer)
?FeedbackSegmentedQuestionsFragment.Feedback2Answer3String:AppData.Instance.FeedbackSubmissionData.Feedback2Question3Answer;
//SetFragmentData (AppData.Instance.FeedbackSubmissionData.Feedback2Question3Answer, position);
} else {
feedback2Question3Answer = FeedbackSegmentedQuestionsFragment.Feedback2Answer3String;
}
}
if (!Utils.IsStringNullOrEmptyOrWhiteSpace (feedback2Question3Answer)) {
string[] ansarr = new string[feedback2Question3Answer.Split (',').Length];
ansarr = feedback2Question3Answer.Split (',');
switch (ansarr [position].Split (':') [1].ToLower ()) {
case "a":
_activity.Activity.RunOnUiThread (() => {
holder.RadioButton1.SetBackgroundResource (Resource.Drawable.GreenButton_BlackBorder);
//holder.RadioButton1.SetBackgroundColor (Android.Graphics.Color.LimeGreen);
holder.RadioButton2.SetBackgroundResource (0);
holder.RadioButton2.SetBackgroundColor (new Android.Graphics.Color(255,255,0,255));
holder.RadioButton3.SetBackgroundResource (0);
holder.RadioButton3.SetBackgroundColor (new Android.Graphics.Color(255,0,0,255));
});
//holder.RadioButton1.Checked = true;
//holder.RadioButton2.Checked = false;
//holder.RadioButton3.Checked = false;
break;
case "b":
_activity.Activity.RunOnUiThread (() => {
holder.RadioButton2.SetBackgroundResource (Resource.Drawable.YellowButton_BlackBorder);
//holder.RadioButton2.SetBackgroundColor (Android.Graphics.Color.Yellow);
holder.RadioButton1.SetBackgroundResource (0);
holder.RadioButton1.SetBackgroundColor (new Android.Graphics.Color(0,255,0,255));
holder.RadioButton3.SetBackgroundResource (0);
holder.RadioButton3.SetBackgroundColor (new Android.Graphics.Color(255,0,0,255));
});
//holder.RadioButton1.Checked = false;
//holder.RadioButton2.Checked = true;
//holder.RadioButton3.Checked = false;
break;
case "c":
_activity.Activity.RunOnUiThread (() => {
holder.RadioButton3.SetBackgroundResource (Resource.Drawable.RedButton_BlackBorder);
//holder.RadioButton3.SetBackgroundColor (Android.Graphics.Color.Red);
holder.RadioButton1.SetBackgroundResource (0);
holder.RadioButton1.SetBackgroundColor (new Android.Graphics.Color(0,255,0,255));
holder.RadioButton2.SetBackgroundResource (0);
holder.RadioButton2.SetBackgroundColor (new Android.Graphics.Color(255,255,0,255));
});
//holder.RadioButton1.Checked = false;
//holder.RadioButton2.Checked = false;
//holder.RadioButton3.Checked = true;
break;
default:
holder.RadioButton2.SetBackgroundResource (Resource.Drawable.YellowButton_BlackBorder);
//holder.RadioButton2.SetBackgroundColor (Android.Graphics.Color.Yellow);
holder.RadioButton1.SetBackgroundResource (0);
holder.RadioButton1.SetBackgroundColor (new Android.Graphics.Color(0,255,0,255));
holder.RadioButton3.SetBackgroundResource (0);
holder.RadioButton3.SetBackgroundColor (new Android.Graphics.Color(255,0,0,255));
//holder.RadioButton1.Checked = false;
//holder.RadioButton2.Checked = true;
//holder.RadioButton3.Checked = false;
break;
}
if (ChallengeFeedbackActivity.ReviewState) {
holder.RadioButton1.Enabled = false;
holder.RadioButton2.Enabled = false;
holder.RadioButton3.Enabled = false;
}
}
return view;
}
}
1 个答案:
答案 0 :(得分：0)
嗯，简短的回答是，只需关闭你的if (holder == null) {语句两行，这样就可以了：
if (holder == null) {
holder = new ViewHolder ();
view = _activity.Activity.LayoutInflater.Inflate (Resource.Layout.SegmentedControl, parent, false);
}
这是容易的部分（我希望），你遇到问题的原因是因为ListView中的视图被循环使用（以便保留旧值）但是它们不会被循环使用，这就是为什么你看到它表现不一致的原因。我建议你阅读ListView视图回收。这是an article我觉得有帮助。
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