Shulou(Shulou.com)06/02 Report--

This article mainly introduces the Flex data binding skills, which have certain reference value, interested friends can refer to, I hope you have a lot of gains after reading this article, let Xiaobian take you to understand.

Flex Data Binding Tips

There is an easy way to activate/deactivate controls by checking them. For example, suppose you have a DataGrid and buttons that manipulate data. Some of these buttons are only available when a row is selected, others are only available when a row is not selected, and others are only available when a row is selected.

problem

To do this, you may need to write if statements or use Flex data binding to set a variable and then adjust the value of the variable in your code. It's like this:

program code

[Bindable]privatevarsomethingSelected:Boolean=false;

That's a good idea. All controls that depend on the selected state of the DataGrid are bound to a variable. Changing this variable changes the active state of the control. However, you still need to decide when to change this variable. For example:

program code

privatefunctionpublishItem():void{ //gettheselecteditem //publishit grid.selectedItem=-1;//cleartheselection somethingSelected=false; }

Let's complicate things a little bit, assuming that the selected row contains a particular value and that a button is activated. Now you don't just have to pay attention to the variable somethingSelected, you also have to pay attention to this additional check. In other words, you need to set another variable in the publishItem() function. The more constraints there are, the more complex the function becomes.

Flex data binding is a simpler approach

Here's a simpler way. Now that the button is bound to the somethingSelected variable, all that remains is to bind the somethingSelected variable to the state of the DataGrid. You can use the tag:

program code

The somethingSelected value is now bound to the selected state of the DataGrid. Select a row somethingSelected value will become true, and then all tags with enabled="{somethingSelected}" will be activated, all tags with enabled="{! button for "somethingSelected}" is disabled.

The source of a Bingding tag does not have to be a variable. It can be an expression, as shown below. Here source is a simple condition to determine whether the selectedIndex of DataGrid is greater than or equal to 0.

Here's a slightly more complicated example:

program code

If the value of a field in a record of DataGrid is 1, the variable codeOnePicked will change to true.

program code

Here, CheckBox will be selected and buttons will be disabled as long as the selected record code field in DataGrid is 1.

Flex Data Binding Summary

If you have controls in your application that depend on selected state or other UI states, try using tabs to keep your code clean and easier to read and expand.

Thank you for reading this article carefully. I hope that the article "What are the skills of Flex data binding" shared by Xiaobian will be helpful to everyone. At the same time, I hope that everyone will support you more and pay attention to the industry information channel. More relevant knowledge is waiting for you to learn!

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