我的 try catch 功能无法按预期工作

Question

我的程序应该取给定的值并用它找到另一个值。但是，我的 try catch 语句似乎不起作用。它从不执行前 2 个 if 语句，这是程序最重要的部分。当您输入两个值时，第三个确实有效。提前致谢。

        public void calculate(View view) {
    EditText length_find = findViewById(R.id.feet);
    EditText pounds_find = findViewById(R.id.pounds);

    try {
        //int length_int = Integer.parseInt(length_find.getText().toString());
        //int pounds_int = Integer.parseInt(pounds_find.getText().toString());

        double d = .29;
        //double length = length_int;
        //double pounds = pounds_int;
        double w = 24.5 / 12;
        double h = .002 / 12;

        //This Calculates if Pounds are given
        if ((length_find).getText().toString().trim().length() == 0){
            Toast.makeText(MainActivity.this, "Given Pounds", LENGTH_LONG).show();
            int pounds_int = Integer.parseInt(pounds_find.getText().toString());
            double pounds = pounds_int;
            double v = pounds / d;
            double length = v / w / h;
            final TextView mTextView = (TextView) findViewById(R.id.length_show);
            mTextView.setText((int) length);
        }


        //This Calculates if Length is given
        if ((pounds_find).getText().toString().trim().length() == 0){
          Toast.makeText(MainActivity.this, "Given Length", LENGTH_LONG).show();
          int lenght_int = Integer.parseInt(length_find.getText().toString());
          double length = lenght_int;
          double v = length * w * h;
          double answer_pounds = v * d;
          final TextView mTextView = (TextView) findViewById(R.id.pound_show);
          mTextView.setText((int) answer_pounds);
        }
        if((pounds_find).getText().toString().trim().length() > 0 && (length_find).getText().toString().trim().length() > 0){
            Toast.makeText(MainActivity.this, "Whata hell you need me for mate!", LENGTH_LONG).show();
        }

    }
    catch(Exception ex) {
            Toast.makeText(this, "Error", Toast.LENGTH_SHORT).show();
        }

    }

Answer 1

据我了解，

(pounds_find).getText().toString().trim().length() <= 0

或

(length_find).getText().toString().trim().length() <= 0

仅当用户没有输入任何内容时才为真。如果他有，那么第三个“如果”按预期执行。但是当用户没有输入任何内容时

int length_int = Integer.parseInt(length_find.getText().toString());
int pounds_int = Integer.parseInt(pounds_find.getText().toString());

无法完成。因为它是空的。我认为这里就是这种情况。如果不是，请告诉我。如果我错了对不起。这就是我从这里理解的。如果您可以调试并具体说明场景或异常（如果它抛出任何异常），那将更有帮助