在单声道为Android的AddTextChangedListener

我有一个数据库，我正在使用填充列表视图。在这个listview之上有一个edittext，用户在listview中搜索一个项目。根据输入，我希望对listview进行优化和过滤，以仅包含那些与输入类似的项目。这在java中很简单，但在xamarin的android中很难。这里是我的onCreate（）方法，其中数据库填充列表视图。在单声道为Android的AddTextChangedListener

string[] categories; 
protected override void OnCreate (Bundle bundle) 
{ 
    base.OnCreate (bundle); 
    SetContentView(Resource.Layout.b); 
    var destPath = Path.Combine(System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal), "DDxDDB"); 
    System.IO.Stream source = Assets.Open("DDxDDB"); 
    var dest = System.IO.File.Create (destPath); 
    source.CopyTo (dest); 
    var sql = "SELECT _id FROM Sx;"; 
    var conn = new SqliteConnection ("Data Source=" + destPath.ToString()); 
    conn.Open(); 
    var cmd = conn.CreateCommand(); 
    cmd.CommandText = sql; 
    SqliteDataReader reader = cmd.ExecuteReader(); 
    List<string> categ = new List<string>(); 
    while (reader.Read()) 
    { 
     categ.Add(reader.GetString(0)); 
    } 
    categories = categ.ToArray(); 
    ArrayAdapter<string> dataAdapter = new ArrayAdapter<String>(this, Resource.Layout.Main, categories); 
    ListView listView = (ListView) FindViewById(Resource.Id.listView1); 
    listView.Adapter = dataAdapter; 
    listView.TextFilterEnabled = true; 
    EditText myFilter = (EditText)FindViewById(Resource.Id.myFilter); 
    myFilter.AddTextChangedListener(New MyTextWatcher);  
}

这是类，我还包括在本次活动，但我不知道什么添加到代码的方法，以使我的列表视图的过滤。

public class MyTextWatcher: Java.Lang.Object, ITextWatcher 
{ 
    public void AfterTextChanged(IEditable s) {} 
    public void BeforeTextChanged(Java.Lang.ICharSequence arg0, int start, int count, int after) {} 
    public void OnTextChanged(Java.Lang.ICharSequence arg0, int start, int before, int count) {} 
}

来源

2012-12-19 user1518003

你是怎么在Android中做这件事的？也许发布你在那里做的等效代码，那么我会很容易地引导你如何在Mono for Android上做到这一点。 – Cheesebaron

这是我一直使用的例子。我的困难是可以在java中的其他方法而不是c＃中定义方法。 http://stackoverflow.com/questions/5311032/filter-text-from-listview – user1518003

在单对Android的implementaion，EditText已经有三个事件TextChanged，AfterTextChanged和BeforeTextChanged，所以你可以添加委托给每个那些。

来源

2012-12-19 18:07:56

由于aaronmix说EditText有三个事件，您可以使用，而不必实施ITextWatcher类。

所以，你可以将一个EventHandler到AfterTextChanged，并从Event的论据Editable：

var editText = FindViewById<EditText>(Resource.Id.MyEditText); 
editText.AfterTextChanged += (sender, args) => 
{ 
    //do your stuff in here 
    //args.Editable is the equivalent of the `s` argument from Java 
    //afterTextChanged(Editable s) 
};

来源

2012-12-19 23:29:25 Cheesebaron

是谢谢你们两位的帮助。我正在做类似的事情，它的效果很好。这里是：

string[] categories; 

protected override void OnCreate (Bundle bundle) 
{ 
    base.OnCreate (bundle); 
    SetContentView(Resource.Layout.b); 
    var destPath = Path.Combine(System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal), "DDxDDB"); 
    System.IO.Stream source = Assets.Open("DDxDDB"); 
    var dest = System.IO.File.Create (destPath); 
    source.CopyTo (dest); 
    var sql = "SELECT _id FROM Sx;"; 
    var conn = new SqliteConnection ("Data Source=" + destPath.ToString()); 
    conn.Open(); 
    var cmd = conn.CreateCommand(); 
    cmd.CommandText = sql; 
    SqliteDataReader reader = cmd.ExecuteReader(); 
    List<string> categ = new List<string>(); 
    while (reader.Read()) 
    { 
     categ.Add(reader.GetString(0)); 
    } 
    categories = categ.ToArray(); 
    ArrayAdapter<string> dataAdapter = new ArrayAdapter<String>(this, Resource.Layout.Main, categories); 
    ListView listView = (ListView) FindViewById(Resource.Id.listView1); 
    listView.Adapter = dataAdapter; 
    listView.TextFilterEnabled = true; 
    EditText myFilter = (EditText)FindViewById(Resource.Id.myFilter); 
    myFilter.TextChanged += new EventHandler<TextChangedEventArgs>(OnTextChange); 
} 

public void OnTextChange(object sender, EventArgs e) 
{   
    EditText myFilter = (EditText)FindViewById(Resource.Id.myFilter); 
    string val = myFilter.Text.ToString(); 
    List<string> categ2 = new List<string>(); 
    foreach (string value in categories) 
    { 
     if (value.IndexOf(val, StringComparison.CurrentCultureIgnoreCase) != -1) 
     { 
      categ2.Add(value); 
     } 
    } 
    string[] categories2 = categ2.ToArray(); 
    ArrayAdapter<string> dataAdapter = new ArrayAdapter<String>(this, Resource.Layout.Main, categories2); 
    ListView listView = (ListView) FindViewById(Resource.Id.listView1); 
    listView.Adapter = dataAdapter; 
    listView.TextFilterEnabled = true; 
}

来源

2012-12-20 00:37:22 user1518003

在单声道为Android的AddTextChangedListener

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