如何验证是否DataGridViewCheckBoxCell被选中 [英] How to verify if a DataGridViewCheckBoxCell is Checked

问题描述

我已绑定一个数据表到 DataGridView的，这个数据表有一个名为状态列是类型布尔。我可以将值设置为真正或假通过代码就好了。

不过，我无法弄清楚如何检查，看看是否给定的行已经被选中。这是我想使用和编译它显示错误指定的强制转换无效的代码。

任何帮助，将不胜感激。

 如果（rowIndex位置> = 0）
 {
 VAR cbxCell =（DataGridViewCheckBoxCell）dgvScan.Rows [rowIndex位置] .Cells [ 状态]; 
 
如果（（布尔）cbxCell.Value）
 {
 //做的东西
} 
，否则
 {
 / /做其他的东西
} 
} 
  

解决方案

问题是，对于一个DataGridCheckBoxColumn默认FALSE值为null，并且默认TRUE值为True布尔值。这会导致一个问题，因为布尔值不为空。你能解决这个问题的方法有两种：！

 如果（cbxCell.Value = NULL&放大器;及（布尔）cbxCell.Value ）
 {
做的东西; 
} 
  

另一种方式来解决这个设置列的TrueValue属性一些值。这可以在设计时进行，如下所示：

然后，你可以写：

 如果（（字符串）cbxCell.Value ==T）
 {
做的东西; 
} 
  

这工作，因为字符串是空。

请注意：即使我设置FalseValue为f假值似乎仍然是空的，所以我建议忽略了FalseValue财产

另一个注意：如果你把东西TrueValue如上然后学尝试删除它，真值变为零（哎哟），requireing您删除列，然后才能将其恢复到初始状态重新添加它。或者你可以在代码如下更改：

 （（DataGridViewCheckBoxColumn）DataGridView1.Columns [选择]）TrueValue =真正的
  

I have bound a data table to a DataGridView, this data table has a column called "Status" which is of type Boolean. I can set the value to true or false just fine via code.

However, I can't figure out how to check to see if the given row is already checked or not. This is the code I am trying to use and compiling it shows the error "the specified cast is invalid".

Any help would be appreciated.

if (rowIndex >= 0)
{
    var cbxCell = (DataGridViewCheckBoxCell)dgvScan.Rows[rowIndex].Cells["Status"];

    if ((bool)cbxCell.Value)
    {
        // Do stuff
    }
    else
    {
        // Do other stuff
    }
}

解决方案

The problem is that the default FALSE value for a DataGridCheckBoxColumn is null, and the Default TRUE value is the boolean value True. This causes a problem because boolean values are not nullable. You can solve this problem two ways:

    if (cbxCell.Value != null && (bool)cbxCell.Value)
    {
        do stuff;
    }

The other way to solve this is set the TrueValue property of the column to some value. This can be done at design time as shown:

Then you can write:

    if ((string)cbxCell.Value == "T")
    {
        do stuff;
    }

This works because Strings are nullable.

Please note: Even though I set the FalseValue to be F the false value still seems to be null, so I suggest ignoring the FalseValue property.

One other note: IF you put something in TrueValue as above and then attemp to erase it, True value becomes null (ouch), requireing you to delete the column and then re-add it in order to restore it to the default condition. Or you can change it in code as follows:

((DataGridViewCheckBoxColumn)DataGridView1.Columns["Selected"]).TrueValue = true

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