Question

我得到两个EditText的整数，并在其中一个上应用textWatch，将它们相乘并将文本设置为另一个EditText。它通常工作正常但当其中一个编辑字段变空时，同时遇到退格应用程序崩溃。

protected final TextWatcher getValueWatcher = new TextWatcher() {
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    }
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        int qty = Integer.parseInt(s.toString());
        int unitPrice = Integer.parseInt(unitPriceEdit.getText().toString());
        if (s.length() > 0)
        totalPriceEdit.setText(String.valueOf(qty * unitPrice));
    }
    public void afterTextChanged(Editable s) {
    }
};

logcat的

java.lang.NumberFormatException: Invalid int: "" at 
java.lang.Integer.invalidInt(Integer.java:138) at 
java.lang.Integer.parseInt(Integer.java:358) at 
java.lang.Integer.parseInt(Integer.java:334) at 
com.example.fani.project.MainActivity$2.onTextChanged(MainActivity.java:90) 
at android.widget.TextView.sendOnTextChanged(TextView.java:7679) at 
android.widget.TextView.handleTextChanged(TextView.java:7739)

Answer 1

将代码替换为如下

protected final TextWatcher getValueWatcher = new TextWatcher() {
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    }
    public void onTextChanged(CharSequence s, int start, int before, int count) {
      if (s.length() > 0){
        int qty = Integer.parseInt(s.toString());
        int unitPrice = Integer.parseInt(unitPriceEdit.getText().toString());
        totalPriceEdit.setText(String.valueOf(qty * unitPrice));
      }
    }
    public void afterTextChanged(Editable s) {
    }
};

在解析之前检查字符串的长度..

Answer 2

修改你的onTextChanged（）：

public void onTextChanged(CharSequence s, int start, int before, int count) {
    if (s.length() > 0){
        int qty = Integer.parseInt(s.toString());
        int unitPrice = Integer.parseInt(unitPriceEdit.getText().toString());
        totalPriceEdit.setText(String.valueOf(qty * unitPrice));
    }
}

Answer 3

由于

var owl;

$(document).ready(function() {
    owl = $("#owl-demo");
    owl.owlCarousel({
        navigation: false,
        slideSpeed: 300,
        paginationSpeed: 400,
        singleItem: true,
        afterInit: afterOWLinit
    });

    function afterOWLinit() {
        ...
    }

});

而发生

空指针错误在您的代码中更改此内容。

s.length > 0

要

 if (s.length() > 0)
    totalPriceEdit.setText(String.valueOf(qty * unitPrice));
 }

将字符串转换为Integer时的NumberFormatException

3 个答案: