Auto Expand Flex Tree Nodes After Data Binding

In Flex, you can bind data to a Tree component by setting the dataProvider, and you can automatically expand tree nodes by setting the openItems property. The specific steps are as follows:

1. Set the data to be bound as an array and assign it to the Tree component’s dataProvider property. For example:

var treeData:Array = [
    {label:"Node 1", children:[
        {label:"Child Node 1"},
        {label:"Child Node 2"}
    ]},
    {label:"Node 2", children:[
        {label:"Child Node 3"},
        {label:"Child Node 4"}
    ]}
];

myTree.dataProvider = treeData;

1. Specify the path of the node to be automatically expanded and assign it to the openItems property. For example, to expand the first node and its first child node, you can set it like this:

myTree.openItems = [treeData[0], treeData[0].children[0]];

1. After the nodes in the Tree component have finished rendering, the specified node path will be automatically expanded.

By following the above steps, you can bind data to the Tree component in Flex and automatically expand tree nodes.