zoukankan      html  css  js  c++  java
  • WPF DataGrid点击有效区域Check

    1、DataGrid注册左键事件,点击有效区域Check

    //在窗体Load中增加
    this.dataGrid.AddHandler(DataGrid.MouseLeftButtonDownEvent, new MouseButtonEventHandler(this.DataGrid_MouseLeftSingleButtonDown), true);
    
    //添加右键事件
    private void DataGrid_MouseLeftSingleButtonDown(){
        if(Utility.ignoreDataGridMouseLeftSingleButtonDown(sender,e) == false){
            SelectedChange();
        }		
    } 
    
    //DataGrid 点击检查判断
    //用户是否点击在了DataGrid有效区域,而不是表格内空白,滚动条,列名等无效区域
    //返回值true:忽略该鼠标点击事件
    public static bool ignoreDataGridMouseLeftSingleButtonDown(object sender,MouseButtonEventArgs e){
        DataGrid grid = sender as DataGrid;
        if(grid == null || (grid.DataContext == null && grid.ItemsSource == null)){
            return true;
        }
        bool isDataContextNull = false;
        if(grid.DataContext == null && grid.ItemsSource != null){
            isDataContextNull = true;
            grid.DataContext = grid.ItemsSource;
        }
        bool ignored = false;
        Point p = e.GetPosition(grid);
        if(grid.VerticalScrollBarVisibility == ScrollBarVisibility.Visible){
            if(p.X > grid.ActualWidth - SystemParameters.VerticalScrollBarWidth){
                ignored = true;
            }
        }
        
        if(ignored == false && grid.HorizontalScrollBarVisibility == ScrollBarVisibility.Visible){
            if(p.Y > grid.ActualHeight - SystemParameters.HorizontalScrollBarWidth ||
               p.Y < grid.ColumnHeaderHeight){
                ignored = true;
            }
        }
        
        //点击在表头
        if(ignored == false){
            DataGridColumnHeadersPresenter headerPresenter = FindVisualChild<DataGridColumnHeadersPresenter>(grid);
            if(p.Y < headerPresenter.ActualHeight){
                ignored = true;
            }
        }
        
        //数据行是否显示满了 是否有空白区域
        if(ignored == false){
            //其绑定的上下文不是一个List类型
            if(grid.DataContext.GetType().GetProperty("Count") ==null){
               if(isDataContextNull){
                   grid.DataContext = null;
               } 
                return ture;
            }
             //如果有数据  计算是否点在空白区域
        int count;
        if(int.TryParse(grid.DataContext.GetType().GetProperty("Count").GetValue(grid.DataContext).ToString(), out count)){
            double totalHeight = 0;
            for(int i=0;i<count ; i++){
                DataGridRow row = (DataGridRow)grid.ItemContainerGenerator.ContainerFromIndex(i);
                if(row != null){
                    totalHeight += row.ActualHeight;
                }
            }
            if(totalHeight +grid.ColumnHeaderHeight < p.Y){
               ignored = true; 
            }
        }       
        }
        if(isDataContextNull){
            grid.DataContext = null;
        }
        return ignored;   
    }
    
    public static T FindVisualChild<T>(DependencyObject current) where T :DependencyObject{
        if(current == null) return null;
        int childCount = VisualTreeHelper.GetChildrenCount(current);
        for(int i=0; i< childCount; i++){
           DependencyObject child = VisualTreeHelper.GetChild(current, i);
            if(child is T)return (T)child;
            T result = FindVisualChild<T>(child);
            if(result != null) return result;        
        }
        return null;
    }
    
    
  • 相关阅读:
    Matplotlib.pyplot 三维绘图
    Matplotlib.pyplot 二维绘图
    面对对象进阶
    面对对象基础
    python安装第三方模块
    json & pickle
    os模块
    sys模块
    正则表达式
    Python2与Python3的编码差异
  • 原文地址:https://www.cnblogs.com/DingGuo/p/14515661.html
Copyright © 2011-2022 走看看