为什么我画UCGUI界面的过程中STM32的定时器进不了中断服务函数？

如题，我注释了画UCGUI界面的函数，我的定时器中断服务函数就能进入了，但我在画UCGUI界面的过程中，我无法进入定时器中断服务函数！搞不懂这个是什么问题！
部分UCGUI画界面函数如下：
1.（画如下这个界面的过程中，无法进入定时器中断）：
[C] 纯文本查看 复制代码
void Draw_Check_Screen(void){int rate = Heart_Rate;int height = Height;int west = West;int east = East;if(Screen_Change == 1)  //??????????????±???{GUI_ClearRect(0,0,128,128);//????±??°????????}Draw_Header();//????????GUI_DrawBitmap(&bm30x30heart_rate,10,30);//??????????±êGUI_DrawBitmap(&bm30x30navigation,10,80);//?????¨????±êGUI_SetColor(GUI_BLUE);GUI_DrawLine(10,67,117,67);//???????????±??GUI_SetColor(GUI_WHITE);GUI_SetFont(&GUI_Font8x8);//?è??×???GUI_GotoXY(50,40);//?è???±?°??±?????GUI_DispDecMin(rate);//??????????GUI_GotoXY(50,85);//?è???±?°??±?????GUI_DispDecMin(east);//??????????????GUI_DispChars('E',1);GUI_GotoXY(90,85);//?è???±?°??±?????GUI_DispDecMin(west);//??????????????GUI_DispChars('W',1);GUI_GotoXY(50,103);//?è???±?°??±?????GUI_DispDecMin(height);//??????????????GUI_DispChars('H',1);}
2.（画如下这个界面的时候，进不了定时器中断服务函数）：
[C] 纯文本查看 复制代码
void Draw_Phone_Screen(void){char string1[15] = "Calling...";char string2[15] = "Your telegram";char string3[15] = "On the phone";char ac[] = "Select number:";char xPosition1 = 20;char yPosition1 = 68;char xPosition2 = 20;char yPosition2 = 88;char xPosition3 = 20;char yPosition3 = 108;unsigned char i;char phone[11] ;//?????????????°????for(i = 0;i <11;i++){phone = Phone_Number;//???????°????}if(Screen_Change == 1)  //??????????????±???{GUI_ClearRect(0,0,128,128);//????±??°????????}Draw_Header();//????????switch (K1_Count){case PHONE_DIALING :       //????????????GUI_DrawBitmap(&bm30x30calling,50,30);//??????????±êGUI_SetFont(&GUI_Font8x8);//?è??×???GUI_GotoXY(4,70);//?è???±?°??±?????GUI_DispString(string1);GUI_GotoXY(20,100);//?è???±?°??±?????GUI_DispString(phone);//???????°????break;case PHONE_COMING ://????????????GUI_DrawBitmap(&bm30x30incoming,50,30);//??????????±êGUI_SetFont(&GUI_Font8x8);//?è??×???GUI_GotoXY(4,70);//?è???±?°??±?????GUI_DispString(string2);GUI_GotoXY(20,100);//?è???±?°??±?????GUI_DispString(phone);//???????°????break;case PHONE_CALLING ://?????¨?°??????GUI_DrawBitmap(&bm30x30ontheline,50,30);//??????????±êGUI_SetFont(&GUI_Font8x8);//?è??×???GUI_GotoXY(4,70);//?è???±?°??±?????GUI_DispString(string3);GUI_GotoXY(20,100);//?è???±?°??±?????GUI_DispString(phone);//???????°????break;case PHONE_SCREEN ://?????¨?°???????? ????????????GUI_SetFont(&GUI_Font8x8);GUI_GotoXY(7,40);//?è???±?°??±?????GUI_DispString(ac);GUI_GotoXY(30,70);//?è???±?°??±?????GUI_DispString(number1);GUI_GotoXY(30,90);//?è???±?°??±?????GUI_DispString(number2);GUI_GotoXY(30,110);//?è???±?°??±?????GUI_DispString(number3);GUI_ClearRect(0,60,29,128);//????±??°?????????????????ò//????????????????????±êif(K2_Count == PHONE_NUMBER_1)GUI_AA_FillPolygon(Number_Select,GUI_COUNTOF(Number_Select),4 * (xPosition1),4 * (yPosition1));else if(K2_Count == PHONE_NUMBER_2)GUI_AA_FillPolygon(Number_Select,GUI_COUNTOF(Number_Select),4 * (xPosition2),4 * (yPosition2));else if(K2_Count == PHONE_NUMBER_3)GUI_AA_FillPolygon(Number_Select,GUI_COUNTOF(Number_Select),4 * (xPosition3),4 * (yPosition3));break;default :break;}}
请各位大神支招！万分感谢！