QTextEdit

main.cpp

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#include <QTextEdit>
#include <QVBoxLayout>
#include <QPushButton>
#include <QLabel>
#include <qapplication.h>

void setupTextEditDemo(QWidget *parent) {
    QVBoxLayout *layout = new QVBoxLayout(parent);

    // --- 1. 创建多行文本框 ---
    QTextEdit *textEdit = new QTextEdit(parent);
    textEdit->setPlaceholderText("请输入详细描述内容（支持 HTML 标签）...");

    // 设置一些初始内容
    textEdit->setPlainText("这是一段纯文本初始内容。");

    // --- 2. 控制按钮：插入 HTML 内容 ---
    QPushButton *btnHtml = new QPushButton("插入红色加粗文字", parent);
    QObject::connect(btnHtml, &QPushButton::clicked, [textEdit]() {
        // append 是在末尾追加，insertHtml 是在光标处插入
        textEdit->insertHtml("<b style='color:red;'> [新内容] </b>");
    });

    // --- 3. 统计字数的标签 ---
    QLabel *countLabel = new QLabel("当前字数：10", parent);

    // --- 4. 信号：textChanged ---
    // 注意：QTextEdit 的 textChanged() 信号不带参数，需要手动获取文本
    QObject::connect(textEdit, &QTextEdit::textChanged, [textEdit, countLabel]() {
        // toPlainText() 获取不带格式的纯文字
        QString content = textEdit->toPlainText();
        countLabel->setText(QString("当前字数：%1").arg(content.length()));
    });

    // --- 5. 清空按钮 ---
    QPushButton *btnClear = new QPushButton("清空全部", parent);
    QObject::connect(btnClear, &QPushButton::clicked, [textEdit]() {
        textEdit->clear();
    });

    layout->addWidget(new QLabel("多行编辑器："));
    layout->addWidget(textEdit);
    layout->addWidget(countLabel);
    layout->addWidget(btnHtml);
    layout->addWidget(btnClear);
}
int main(int argc, char *argv[]) {
    QApplication a(argc, argv);

    QWidget w;
    w.setWindowTitle("QLineEdit 深度测试");
    w.resize(400, 300);

    // 调用我们的函数
    setupTextEditDemo(&w);

    w.show();
    return a.exec();
}