Question

C++BUILDER中,对TEdit控件用上下左右箭头实现各个TEdit焦点的切换?

对TEdit控件用上下左右箭头实现各个TEdit焦点的切换,如何实现?

Answer 1

先手动拖入4个Edit。

H里追加：
private: // User declarations
TEdit * mpEditList[4];

FormCreate里追加：
void __fastcall TForm1::FormCreate(TObject *Sender)
{
mpEditList[0] = this->Edit1;
mpEditList[1] = this->Edit2;
mpEditList[2] = this->Edit3;
mpEditList[3] = this->Edit4;
}

4个Edit都选上，F11，OnKeyDown的消息对应同一个函数：
void __fastcall TForm1::Edit1KeyDown(TObject *Sender, WORD &Key,
TShiftState Shift)
{
TEdit * edit = (TEdit*)Sender;
long nIndex = -1;
for (long k=0; k<4; k++)
{
if (edit == mpEditList[k])
{
nIndex = k;
break;
}
}
if (nIndex == -1)
return;

long nIndexNew = nIndex;
if (Key == VK_DOWN)
{
if (nIndexNew<4-1)
nIndexNew ++;
}

if (Key == VK_UP)
{
if (nIndexNew>0)
nIndexNew --;
}

mpEditList[nIndexNew]->SetFocus();
}

VK_DOWN 等的定义查看C++builder Help:
Virtual Key Codes