c# how do i check if datasource is null?

i have a control on a winform called chart1.

i would like to know whether chart开发者_如何转开发1.DataSource is empty

how do i check it?

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If the DataSource is a DataTable, you can check first that the DataTable is not null, and secondly that its Rows.Count > 0.

If the DataSource is a DataSet, you check for null, then tables, then rows.

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Check to see if it is null.

if(chart1.DataSource == null)
{
 // Do something
}

If you know what the DataSource is, then you can cast it and check to see if it is empty or not. For example:

List<String> strings = new List<String>() { "a", "b" };

// Set chart1.DataSource to strings... then later on
if(chart1.DataSource != null)
{
   List<String> boundStrings = chart1.DataSource as List<String>;
   if(boundStrings != null && boundStrings.Count > 0)
   {
      // do something
   }
}

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personally id check the datasource for null BEFORE I bind it to chart so I don't have to worry about chart1 dealing with a null datasource

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if (chart1.DataSource == null)
{
    // The DataSource is empty
}