Question

我有按钮和textView。当我点击按钮时，timePicker将显示出来。但是，当我完成设置一小时和一分钟并将在TextView中显示它时，它很遗憾地停止

我的代码：

protected Dialog onCreateDialog(int id) {
    switch (id) {
    case TIME_DIALOG_ID:
        return new TimePickerDialog(this, timePickerListener, hour, minute, true);
    }
    return null;
}
private TimePickerDialog.OnTimeSetListener timePickerListener = 
        new TimePickerDialog.OnTimeSetListener() { 
        public void onTimeSet(TimePicker view, int selectedHour,int selectedMinute) {

        hour = selectedHour;
        minute = selectedMinute;

        //error here================= What's Wrong?
        tvDisplayTime.setText(new StringBuilder().append(pad(hour)).append(":")
       .append(pad(minute)));
        }}; 
       // ===============================
private static String pad(int c) {
    if (c >= 10)
       return String.valueOf(c);
    else
       return "0" + String.valueOf(c);
}
}

为什么当我尝试从TimePicker设置小时和分钟并在TextView中显示总是错误？

请帮忙......

记录：

07-27 18:14:24.661: E/SpannableStringBuilder(7324): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length 07-27 18:14:24.661: E/SpannableStringBuilder(7324): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length 07-27 18:14:30.901: D/AndroidRuntime(7324): Shutting down VM 07-27 18:14:30.901: W/dalvikvm(7324): threadid=1: thread exiting with uncaught exception (group=0x42034438) 07-27 18:14:30.911: E/AndroidRuntime(7324): FATAL EXCEPTION: main 07-27 18:14:30.911: E/AndroidRuntime(7324): java.lang.NullPointerException 07-27 18:14:30.911: E/AndroidRuntime(7324): at com.example.b_timepicker.MainActivity$1.onTimeSet(MainActivity.java:98) 07-27 18:14:30.911: E/AndroidRuntime(7324): at android.app.TimePickerDialog.tryNotifyTimeSet(TimePickerDialog.java:201) 07-27 18:14:30.911: E/AndroidRuntime(7324): at android.app.TimePickerDialog.onClick(TimePickerDialog.java:165) 07-27 18:14:30.911: E/AndroidRuntime(7324): at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:167) 07-27 18:14:30.911: E/AndroidRuntime(7324): at android.os.Handler.dispatchMessage(Handler.java:99) 07-27 18:14:30.911: E/AndroidRuntime(7324): at android.os.Looper.loop(Looper.java:137) 07-27 18:14:30.911: E/AndroidRuntime(7324): at android.app.ActivityThread.main(ActivityThread.java:4963) 07-27 18:14:30.911: E/AndroidRuntime(7324): at java.lang.reflect.Method.invokeNative(Native Method) 07-27 18:14:30.911: E/AndroidRuntime(7324): at java.lang.reflect.Method.invoke(Method.java:511) 07-27 18:14:30.911: E/AndroidRuntime(7324): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038) 07-27 18:14:30.911: E/AndroidRuntime(7324): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805) 07-27 18:14:30.911: E/AndroidRuntime(7324): at dalvik.system.NativeStart.main(Native Method)

Answer 1

请确保您正确声明tvDisplayTime TextView，因此当您致电setText()时，它不会为空。还要确保在正确的布局上定义了tvDisplayTime。

android：textView不能从TimePicker设置文本时间

1 个答案: