如何从 CEdit 控件获取文本 [英] How to get text from CEdit control

问题描述

我是 ATL 的新人.所以请原谅我提出这个问题.

I'm a new guy with ATL. So forgive me to ask this question.

问题描述:一个 CEdit 控件被添加到 ATL 对话框类中.它附加在对话框初始化函数中.

Problem description: One CEdit control is added into a ATL dialog class. It's attached in the dialog initialize function.

//Define the edit control
ATLControls::CEdit  m_txtInput;

//In the OnInitDialog function
m_txtInput.Attach(GetDlgItem(IDC_INPUT_LINE));

m_txtInput.SetWindowText(_T("New directory"));

//In the public memeber function of the dialog GetInput()
//I have tried three kinds of method to get the text. But all of them are throw an 
//assert exception, IsWindow() failed. 
//1.
GetDlgItemText(IDC_INPUT_LINE, input);
//2.
ZeroMemory(m_lptstrInput, MAX_PATH);
m_txtInput.GetLine(0, m_lptstrInput, MAX_PATH);
//3.
BSTR input; 
m_txtInput.GetWindowText(input);

这里是关于如何从获取文本的主题CEdit 但它不起作用.

Here is a topic about how to get text from CEdit but it is not working.

为什么CEdit控件可以通过SetWindowText()函数设置文本，但不能通过GetWindowText()函数获取文本>?这真的让我很困惑.如果有人能帮我解释一下，非常感谢.

Why the CEdit control could be set text with the function SetWindowText() but can't get the text by the function GetWindowText()? It's really confuse me. Thanks a lot if someone could explain it for me.

推荐答案

CEdit 不是 ATL 类.命名空间 ATLControls 来自哪里?有一个具有此名称的 WTL 类，从中获取文本很容易:

CEdit is not an ATL class. Where the namespace ATLControls comes from? There is a WTL class with this name and getting text from it is easy:

    ATLASSERT(Edit.IsWindow()); // Make sure the control holds a handle
    CString sWindowText;
    Edit.GetWindowText(sWindowText);

GetWindowText 方法来自 ATL 并且封装了 GetWindowTextLength 和 GetWindowText API.后一篇 MSDN 文章也有一段代码片段展示了典型用法.

The method GetWindowText is coming from ATL however and wraps GetWindowTextLength and GetWindowText API. The latter MSDN article also has a code snippet showing typical usage.

既然您提到 IsWindow 对您不起作用，那么最可能的问题是您的编辑控件包装类变量没有实际控件的句柄，因此从无到有获取文本不可能.

Since you mention that IsWindow does not work for you, the most likely problem is that your edit control wrapper class variable just does not have a handle of a real control, and hence getting text from nothing is impossible.

这篇关于如何从 CEdit 控件获取文本的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！