也许这是一个愚蠢的问题，但我不能想怎么解决它，如果它不是创建一个方法。也许有一个自然的方式来做到这一点，就像在C为例。这里的问题：

我有一个变种：

 双A;
 

和我想只有2或3位小数表现出来。当我试图表现出来：

  Text.setText（价值一：+将String.valueOf（一））;
 

它给这样的：

的价值：5.234966145

和我想只是

值：5.23

在不改变的实际值，因此它显示的大致数目，但工作原理与实数。

  Text.setText（的String.Format（一个价值：％.2f，一））;
 

Maybe this is a silly question, but I cannot guess how to solve it if it's not creating a method. Maybe there's a "natural way" to do it, like in C for example. Here's the problem:

I have a var:

double a;

And I want to show it only with 2 or 3 decimals. When I try to show it:

Text.setText("Value of a: " + String.valueOf(a));

It gives something like:

Value of a: 5.234966145

And i would want just

Value of a: 5.23

Without changing the real value of a so it shows the approximate number but works with the real number.

Text.setText( String.format( "Value of a: %.2f", a ) );