Question

首先我的英语不是很好，但是我会尽力而为。

我想要一个txt字段和一个指向下一页的按钮，但是文本字段必须为文本。

如果该字段为空，则该按钮不应转到另一页

希望有人能理解我

thnx

Answer 1

有帮助吗？

  Row(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: <Widget>[
              Container(
                margin: EdgeInsets.only(
                    right: 16
                ),
                child: ClipRRect(
                  borderRadius: BorderRadius.circular(16),
                  child: Image.asset(
                      'assets/photo.jpg',
                      width: 160
                  ),
                ),
              ),
              Expanded(
                child: Container(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: <Widget>[
                        Container(
                            margin: EdgeInsets.only(bottom: 16),
                            child: Text(
                              "Wonderful haircut",
                              style: TextStyle(
                                  fontSize: 20
                              ),
                            )
                        ),
                        Container(
                          child: Text(
                            "An undercut is typecally a cut done with clippers in the back.",
                            style: TextStyle(
                                fontSize: 18
                            ),
                          ),
                        ),
                        Container(
                          margin: EdgeInsets.only(top: 30),
                          padding: EdgeInsets.symmetric(vertical: 6, horizontal: 16),
                          decoration: BoxDecoration(
                              color: Colors.red,
                              borderRadius: BorderRadius.circular(16)
                          ),
                          child: Text(
                              "\$50",
                              style: TextStyle(
                                  fontSize: 20,
                                  color: Colors.white
                              )
                          ),
                        )
                      ],
                    )
                ),
              )
            ],
          )

var nextButton = document.getElementById("nextButton");
var textField = document.getElementById("textField");
textField.oninput = function() {
  if (textField.value == "") {
    nextButton.disabled = true;
  } else {
    nextButton.disabled = false;
  }
}

Answer 2

您可以在输入标记中使用require属性

<form action="test.php">
<input type="text" required>
<input type="submit">
</form>

放置邮件（必填）并提交到另一页的文本字段

2 个答案: