Question

执行一些操作后，我无法在TextField中显示double值处理它。基本上，我只是将Celcius转变为 FarenHeit在转换器应用程序中。这是代码


   double c = Double.parseDouble(t1.getString());
   double f = c * (9.0D/5.0D) + 32.0D;


Netbeans is giving me the following runtime error

TRACE: , Exception caught in Display class
java.lang.IllegalArgumentException
        at javax.microedition.lcdui.TextField.setCharsImpl(), bci=127
        at javax.microedition.lcdui.TextField.setString(), bci=37
        at ConverterMain.convert(ConverterMain.java:139)
        at ConverterMain.commandAction(ConverterMain.java:66)
        at javax.microedition.lcdui.Display$ChameleonTunnel.callScreenListener(), bci=46
        at com.sun.midp.chameleon.layers.SoftButtonLayer.processCommand(), bci=74
        at com.sun.midp.chameleon.layers.SoftButtonLayer.commandSelected(), bci=11
        at com.sun.midp.chameleon.layers.MenuLayer.keyInput(), bci=290
        at com.sun.midp.chameleon.CWindow.keyInput(), bci=38
        at javax.microedition.lcdui.Display$DisplayEventConsumerImpl.handleKeyEvent(), bci=17
        at com.sun.midp.lcdui.DisplayEventListener.process(), bci=277
        at com.sun.midp.events.EventQueue.run(), bci=179
        at java.lang.Thread.run(Thread.java:619)

Answer 1

setString

f+""

表示在字段

中设置时将其转换为字符串

Answer 2

用如此少的代码很难说清楚。如果我是你，我会添加几个日志，如

System.out.println(t1.getString());
double c = Double.parseDouble(t1.getString());
System.out.println(c);
double f = c * (9.0D/5.0D) + 32.0D;
System.out.println(f);

你确定t1.getString（）是一个有效的Double吗？尝试使用try-catch块

J2ME双值问题

2 个答案: