Vaadin Web应用开发教程(31):UI布局-FormLayout布局

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：

[java]
// 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.")); 

// 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."));
显示如下：

补充：Web开发 , 其他 ,

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