Question

我正在研究一个计算器应用程序，我正在尝试从两个不同的TextView中获取两个字符串值并将它们转换为双精度数，因此我可以对它们进行操作。问题是，当我尝试将字符串转换为双精度数时，它不起作用，并且会使应用程序崩溃。我在try catch块中尝试过它，每次都有一个NumberFormatException。以下是无法正常工作的行：

readRecords

以下是完整代码：

    double doubleContents1 = Double.parseDouble(stringContents1);
// convert first value from string to double
    double doubleContents2 = Double.parseDouble(stringContents2);
// convert second value from string to double

logcat：

public void sendMessageEquals(View view) {
        TextView textView2 = (TextView) findViewById(R.id.textView2);
    // this is the first textview, for the first number
        TextView textView3 = (TextView) findViewById(R.id.textView3);
    // second textview for the second number
        TextView textView4 = (TextView) findViewById(R.id.textView4);
    // third textview for displaying the result from the first two
        String stringContents1 = (String) textView2.getText();
    // get the value from the first textview
        String stringContents2 = (String) textView3.getText();
    // get the value from the second textview
        double doubleContents1 = Double.parseDouble(stringContents1);
    // convert first value from string to double
        double doubleContents2 = Double.parseDouble(stringContents2);
    // convert second value from string to double

        if (operator.equals("+")) {
            Double doubleContents3 = doubleContents1 + doubleContents2;
            String stringContents3 = Double.toString(doubleContents3);
            textView4.setText(stringContents3);
            state = "Phase1";
        }
        else if (operator.equals("-")) {
            Double doubleContents3 = doubleContents1 - doubleContents2;
            String stringContents3 = Double.toString(doubleContents3);
        }
        else if (operator.equals("*")) {
            Double doubleContents3 = doubleContents1 * doubleContents2;
            String stringContents3 = Double.toString(doubleContents3);
        }
        else if (operator.equals("/")) {
            if (doubleContents2 != 0) {
                Double doubleContents3 = doubleContents1 / doubleContents2;
                String stringContents3 = Double.toString(doubleContents3);
            }

        }
        else {
            state = "Phase1";
        }

    }

Answer 1

logcat异常表示您的字符串是“操作数1：”，因此无法将其解析为[Tag 1]=>"Tag 1", [Tag 2]=>"Tag 2"。
您应该从Double而不是EditText中获取值。

Answer 2

我的申请中有一个类似的例子。这对我有用：

 double doubleContents1 = Double.parseDouble(textView2.getText().toString());

 double doubleContents2 = Double.parseDouble(textView2.getText().toString());

如果这个剂量有帮助，请通过编辑您的问题发布您的logcat，以便我们查看此错误

如何从TextView中获取字符串并转换为double而不会崩溃？

2 个答案: