Android 日期/时间显示 0 而不是 12

我想知道下面的代码有什么问题：

 // Assign hour set in the picker
        c.set( Calendar.HOUR, selectedHour );
        c.set( Calendar.MINUTE, selectedMinute );

        // For alternative times
        c.add( Calendar.HOUR, SUB_SIX_HOUR );
        c.add( Calendar.MINUTE, SUB_FLAT_MINUTE );

        hour = c.get( Calendar.HOUR );
        minute = c.get( Calendar.MINUTE );
        hour = c.get( Calendar.HOUR_OF_DAY );

        StringBuilder sb4 = new StringBuilder();
        if(hour>=12){                      
          sb4.append(hour-12).append( ":" ).append(minute).append(" PM");
        }else if(hour == 0){
          sb4.append( "12" ).append( ":" ).append(minute).append( "AM" );
        }else{
          sb4.append(hour).append( ":" ).append(minute).append(" AM");
        }


        alternative.setText( "Alternative times: " + sb3 + " (9 hours)" + sb4 + " (6 hours)" );

请帮我弄清楚当计算的时间是午夜 12:00 时如何显示 12 而不是 0。谢谢！

 hour = c.get( Calendar.HOUR );
 minute = c.get( Calendar.MINUTE );
 hour = c.get( Calendar.HOUR_OF_DAY );

您正在设置hour已经设置好后再次进行。