Smart Gwt List Grid:How to check selected records

I am using smart gwt 2.5 List grid. In this I am using check box for simple selection.below is the code for that:

    getGrid().setSelectionAppearance(SelectionAppearance.CHECKBOX);
        getGrid().setSelectionType(SelectionStyle.SIMPLE);

I am using data source for the list grid.For feeding data calling this method:

 public void setTestData(DataClass[] testData) {
    setAttribute("testData", testData, true);
}

My grid is rendering data properly.Now I want to set checked some of records (Row) depending i开发者_如何学Pythonn some condition.Lets say I want row number 1 and 5 should be checked.

For this after feeding data to data source I write code like below to check data:

    getGrid().selectRecord(1);` 
    getGrid().selectRecord(5);

But is not doing any checked operations to check box.I am not getting at what point I am doing mistake. same thing when I tried with out data source and I feed data to list grid simply by setdata It was working. Please help me out.Thanks in advance

When you use a DataSource, including a clientOnly DataSource, fetching data is asynchronous, so your selectRecord() calls are happening when data is not loaded yet. Wait for DataArrived before attempting to select records.

One work around which is working for me is that: I removed selection appearance and selected type from my grid and took a column for check box like below:

    NTListGridField customCheckBoxField = new NTListGridField("select", "Select", 25);
        customCheckBoxField.setAlign(Alignment.LEFT);
        customCheckBoxField.setType(ListGridFieldType.BOOLEAN);
        customCheckBoxField.setCanFilter(false);
        customCheckBoxField.setCanEdit(true);
        customCheckBoxField.setCanToggle(true);

Now for selecting records,

record.setAttribute("select", true);