FormLayout布局为使用表单(Form)时的缺省布局方式。它通常将Field组件的标题和输入域并排以两列的方式显示,并可以显示可选的必填标识。在用户输入错误时显示错误提示。
Form本身可以有标题,错误提示,表单尾注等,具体参见Vaadin Web应用开发教程(23):UI组件-Form组件
FormLayout布局的基本用法如下:
// A FormLayout used outside the context of a Form FormLayout fl = new FormLayout(); // Make the FormLayout shrink to its contents fl.setSizeUndefined(); TextField tf = new TextField("A Field"); fl.addComponent(tf); // Mark the first field as required tf.setRequired(true); tf.setRequiredError("The Field may not be empty."); TextField tf2 = new TextField("Another Field"); fl.addComponent(tf2); // Set the second field straing to error state with a message. tf2.setComponentError( new UserError("This is the error indicator of a Field."));