CAknFloatingPointQueryDialog 浮点数位数的问题

[Juncof]

CAknFloatingPointQueryDialog* input=CAknFloatingPointQueryDialog::NewL(value);
input->PrepareLC(R_DLG_FLOATINPUT);
input->SetMinimumAndMaximum(info.iFloatMin,info.iFloatMax);
if(input->RunLD())
{
}
当定义资源R_DLG_FLOATINPUT的最大长度为12时，对话框可以显示value的初始值，当改为12以上时就不能显示，问一下为什么，怎么改进?
如下是资源：
RESOURCE DIALOG r_dlg_floatinput
{
flags=EGeneralQueryFlags;
buttons=R_AVKON_SOFTKEYS_OK_CANCEL;
items=
{
DLG_LINE
{
type=EAknCtQuery;
id = EGeneralQuery;
control=AVKON_DATA_QUERY
{
layout=EFloatingPointLayout;
control=FLPTED
{ maxlength=12; min=0; max=9999999999.9; default = 0; };
};
}
};
}