此代码执行但不执行操作？ [英] this code getting executed but not doing the action?

问题描述

这是用datagridview中的复选框删除数据行







private void btndelete_Click（对象发件人，EventArgs e）

{



试试

{

foreach （dataGridView1.Rows中的DataGridViewRow行）

{

object cell = row.Cells [dgvdel]。值;

if（cell ==是）

{



if（MessageBox.Show（想要删除，不要，MessageBoxButtons .YesNo）== DialogResult.OK）;

{

javidDataSet.sample_data.Rows [row.Index] .Delete（）;

sample_dataTableAdapter.Update（javidDataSet）;

}



}

}

}



catch（例外情况）

{

}





}



它没有进入消息框循环...

this is to delete the data row with checkbox in datagridview



private void btndelete_Click(object sender, EventArgs e)
{

try
{
foreach (DataGridViewRow row in dataGridView1.Rows)
{
object cell = row.Cells["dgvdel"].Value;
if (cell =="yes")
{

if (MessageBox.Show("Want to delete","Don't", MessageBoxButtons.YesNo) == DialogResult.OK) ;
{
javidDataSet.sample_data.Rows[row.Index].Delete();
sample_dataTableAdapter.Update(javidDataSet);
}

}
}
}

catch (Exception ex)
{
}


}

its not entering into the messagebox loop...

推荐答案

我们无法为您解决此问题 - 我们无法单独运行该代码并获得与您的数据相同的结果。



所以从调试器开始。

在这一行放一个断点：

We can't solve this for you - we can't run that code in isolation and get teh same results you do with your data.

So start with the debugger.
Put a breakpoint on this line:

if (cell =="yes")

并运行你的应用。当它到达断点时，它会停止，让你看看究竟发生了什么。

看看cell的内容 - 它是一个字符串吗？它在确切的文本中是否包含是，或者是字符串是，还是是？



我怀疑因为单元格是一个对象，它是在从单元格返回的值和字符串yes之间进行参考比较 - 在​​这种情况下请尝试这样做：

And run your app. when it hits the breakpoint, it will stop, and let you look at exactly what is going on.
Look at the content of "cell" - is it a string? Does it contain "yes" in that exact text, or is the string "Yes", or "YES"?

I suspect that because cell is an object, it's doing a reference comparison between the value returned from your cell and the string "yes" - in which case try this instead:

foreach (DataGridViewRow row in dataGridView1.Rows)
    {
    string cell = (string) row.Cells["dgvdel"].Value;
    if (cell.ToLower() == "yes")
        {

编译时几乎肯定会收到警告：

You are almost certainly getting a warning for this when you compile:

Possible unintended reference comparison

如果是这样，那么您应该始终将警告视为错误以避免此类问题。

If so, then you should always treat warnings as errors to avoid this kind of problem.

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