Question

我不知道下面代码中的问题是什么。但我知道问题出在哪里。它来自方法createTL() ..它不幸地停止。帮助我解决这个问题。我想要创建EditText视图的n行和4列。编辑：现在我初始化了et和tr ..但仍然出现错误..这是更新的代码

 public TableLayout createTL(int r)
 {
    int c=4;
LayoutParams params = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
myTL=new TableLayout(Ybus_Activity.this);
myTL.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.WRAP_CONTENT, TableRow.LayoutParams.WRAP_CONTENT));
    myTL.setStretchAllColumns(true);
TableRow[] tr = new TableRow[r];
    EditText[][] et = new EditText[r][c];
    Arrays.fill(et,"0.0");
    Arrays.fill(tr,et);
for(int i=0;i<r;i++)
    {
      for(int j=0;j<4;j++)
          {
            et[i][j].setLayoutParams(params);
            et[i][j].setWidth(100);
            et[i][j].setImeOptions(EditorInfo.IME_ACTION_NEXT);
            et[i][j].setInputType(InputType.TYPE_CLASS_NUMBER);
            et[i][j].setKeyListener(DigitsKeyListener.getInstance());
            et[i][j].setMaxLines(1);
            tr[i].addView(et[i][j]);
            myTL.addView(tr[i]);
            }
    }
//I already have LinearLayout named "main" under onCreate() method...
//main.addView(myTL);
return myTL;

}

我的Logcat :(已更新）

02-22 23:15:01.315: D/AndroidRuntime(6445): Shutting down VM
02-22 23:15:01.315: W/dalvikvm(6445): threadid=1: thread exiting with uncaught exception (group=0xb2e26288)
02-22 23:15:01.345: E/AndroidRuntime(6445): FATAL EXCEPTION: main
02-22 23:15:01.345: E/AndroidRuntime(6445): java.lang.ArrayStoreException: java.lang.String cannot be stored in an array of type android.widget.EditText[][]
02-22 23:15:01.345: E/AndroidRuntime(6445):     at java.util.Arrays.fill(Arrays.java:966)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at com.gkn.powersystemcalc.Ybus_Activity.createTL(Ybus_Activity.java:156)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at com.gkn.powersystemcalc.Ybus_Activity$2.onClick(Ybus_Activity.java:140)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at android.view.View.performClick(View.java:4084)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at android.view.View$PerformClick.run(View.java:16966)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at android.os.Handler.handleCallback(Handler.java:615)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at android.os.Handler.dispatchMessage(Handler.java:92)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at android.os.Looper.loop(Looper.java:137)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at android.app.ActivityThread.main(ActivityThread.java:4745)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at java.lang.reflect.Method.invokeNative(Native Method)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at java.lang.reflect.Method.invoke(Method.java:511)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
02-22 23:15:01.345: E/AndroidRuntime(6445):     at dalvik.system.NativeStart.main(Native Method)
02-22 23:15:01.385: W/ActivityManager(1026):   Force finishing activity com.gkn.powersystemcalc/.Ybus_Activity
02-22 23:15:01.545: D/dalvikvm(1026): GC_FOR_ALLOC freed 899K, 11% free 15374K/17159K, paused 84ms, total 86ms
02-22 23:15:02.074: W/ActivityManager(1026): Activity pause timeout for ActivityRecord{b3ac8e38 com.gkn.powersystemcalc/.Ybus_Activity}

Answer 1

您正在EditText发起一个EditText[][] et = new EditText[r][c];数组，但该数组中充满了null个对象。然后，您可以调用这些null个对象上的方法，这就是您获得NullPointerException的原因。

在调用任何方法之前，您需要使用已初始化的et对象填充EditText。

TableRow[] tr = new TableRow[r];

也是如此

修改：注意，您可能希望将返回类型更改为TableLayout，或将myTL对象添加到屏幕上显示的视图中。

难以创建表格布局？

1 个答案: