Xamarin中点击Grid3控件后如何获取Grid1和Grid2的控件值

我正在使用Grid控件，通过循环动态创建控件。现有3个Grid控件，点击Grid3中的控件后，希望获取Grid1和Grid2对应的控件值。

后台原代码 #

Dictionary<string, string[]> myDictionary3 = _Model.getRoomStatusData(_Model.RoomTypesSel, _Model.StartTimeNames);
//Grid 1 x:Name="timelist"
for (int i = 0; i < _Model.StartTimeNames.Length; i++)
{   
    Label time = new Label() { Text = _Model.StartTimeNames[i], WidthRequest = 80 };               
    timelist.Children.Add(time, i, 0);               
}

//Grid 2 x:Name="roomtype"
for (int i = 0; i < roomtypes.Length; i++)
{
    roomtype.RowDefinitions.Add(new RowDefinition());           
    Label room = new Label() { Text = _Model.RoomTypesSel[i].Name, WidthRequest = 80 };      
    roomtype.Children.Add(room, 0, i);
}


List<string[]> roomstatu = new List<string[]>()
{
    new string[] {"1","2","3","4","5","6"}, new string[] {"1","2","3","4","5","6"},new string[] {"1","2","3","4","5","6"},new string[] {"1","2","3","4","5","6"},new string[] {"1","2","3","4","5","6"},new string[] {"1","2","3","4","5","6"},new string[] {"1","2","3","4","5","6"},new string[] {"1","2","3","4","5","6"}
};
//Grid 3 x:Name="status"
int index = 0;
foreach (var item in roomstatu)
{
    status.RowDefinitions.Add(new RowDefinition());
    for (int i = 0; i < item.Length; i++)
    {
        status.ColumnDefinitions.Add(new ColumnDefinition());
        Label statuslabel = new Label() { Text = item[i], WidthRequest = 80};                           
        status.Children.Add(statuslabel, i, index);
    }
    index++;              
}

解决方案 #

核心思路是给Grid3的Label绑定点击事件，通过控件在Grid中的行列索引，关联获取Grid1和Grid2对应位置的控件值。

方法1：直接通过行列索引查找控件

修改Grid3的Label创建逻辑，添加点击事件并获取对应值：

//Grid 3 x:Name="status"
int index = 0;
foreach (var item in roomstatu)
{
    status.RowDefinitions.Add(new RowDefinition());
    for (int i = 0; i < item.Length; i++)
    {
        status.ColumnDefinitions.Add(new ColumnDefinition());
        Label statuslabel = new Label() { Text = item[i], WidthRequest = 80};                           
        
        // 添加点击手势识别器
        var tapGesture = new TapGestureRecognizer();
        tapGesture.Tapped += (sender, e) =>
        {
            var clickedLabel = sender as Label;
            if (clickedLabel == null) return;
            
            // 获取当前Label在Grid3中的行列位置
            int colIndex = Grid.GetColumn(clickedLabel);
            int rowIndex = Grid.GetRow(clickedLabel);
            
            // 获取Grid1（timelist）对应列的时间值
            var timeLabel = timelist.Children.FirstOrDefault(c => Grid.GetColumn(c) == colIndex && Grid.GetRow(c) == 0) as Label;
            string timeValue = timeLabel?.Text ?? string.Empty;
            
            // 获取Grid2（roomtype）对应行的房型值
            var roomLabel = roomtype.Children.FirstOrDefault(c => Grid.GetRow(c) == rowIndex && Grid.GetColumn(c) == 0) as Label;
            string roomTypeValue = roomLabel?.Text ?? string.Empty;
            
            // 此处可对获取到的timeValue和roomTypeValue进行业务处理
        };
        statuslabel.GestureRecognizers.Add(tapGesture);
        
        status.Children.Add(statuslabel, i, index);
    }
    index++;              
}

方法2：提前存储控件列表优化查找效率

如果控件数量较多，遍历Children集合会有性能损耗，可提前将Grid1和Grid2的控件存入列表，后续直接通过索引访问：

1. 创建Grid1时存储控件列表：

List<Label> timeLabelList = new List<Label>();
//Grid 1 x:Name="timelist"
for (int i = 0; i < _Model.StartTimeNames.Length; i++)
{   
    Label time = new Label() { Text = _Model.StartTimeNames[i], WidthRequest = 80 };               
    timelist.Children.Add(time, i, 0);
    timeLabelList.Add(time); // 存入列表
}

2. 创建Grid2时存储控件列表：

List<Label> roomLabelList = new List<Label>();
//Grid 2 x:Name="roomtype"
for (int i = 0; i < roomtypes.Length; i++)
{
    roomtype.RowDefinitions.Add(new RowDefinition());           
    Label room = new Label() { Text = _Model.RoomTypesSel[i].Name, WidthRequest = 80 };      
    roomtype.Children.Add(room, 0, i);
    roomLabelList.Add(room); // 存入列表
}

3. Grid3的点击事件中直接通过索引获取值：

//Grid 3 x:Name="status"
int index = 0;
foreach (var item in roomstatu)
{
    status.RowDefinitions.Add(new RowDefinition());
    for (int i = 0; i < item.Length; i++)
    {
        status.ColumnDefinitions.Add(new ColumnDefinition());
        Label statuslabel = new Label() { Text = item[i], WidthRequest = 80};                           
        
        var tapGesture = new TapGestureRecognizer();
        tapGesture.Tapped += (sender, e) =>
        {
            var clickedLabel = sender as Label;
            if (clickedLabel == null) return;
            
            int colIndex = Grid.GetColumn(clickedLabel);
            int rowIndex = Grid.GetRow(clickedLabel);
            
            // 直接通过索引获取值，无需遍历
            string timeValue = colIndex < timeLabelList.Count ? timeLabelList[colIndex].Text : string.Empty;
            string roomTypeValue = rowIndex < roomLabelList.Count ? roomLabelList[rowIndex].Text : string.Empty;
            
            // 业务处理逻辑
        };
        statuslabel.GestureRecognizers.Add(tapGesture);
        
        status.Children.Add(statuslabel, i, index);
    }
    index++;              
}

内容的提问来源于stack exchange，提问作者Raj