Question

我在公共类中声明了一个变量，然后为该变量分配了if语句，但是在我计算时并没有从if语句获取值。怎么解决呢？这里的完整代码https://pastebin.com/yuaMx4Mk谢谢

    double doubleJarak=Double.parseDouble(jarak);
    double doublewaktu=Double.parseDouble(waktu);
    //SPinner Code
    MaterialSpinner spinner = (MaterialSpinner) findViewById(R.id.spinner);
    spinner.setItems("Premium Rp 7.000", "Pertalite Rp 7.650", "Pertamax Rp 9.850", "Pertamax Turbo Rp 11.200");
    spinner.setOnItemSelectedListener(new MaterialSpinner.OnItemSelectedListener<String>() {

        @Override public void onItemSelected(MaterialSpinner view, int position, long id, String item) {
            //Snackbar.make(view, "Clicked " + item, Snackbar.LENGTH_LONG).show();
            if(position==0)
                hargaBBM=7000;
            else if(position==1)
                hargaBBM=7650;
            else if(position==2)
                hargaBBM=9850;
            else
                hargaBBM=11200;
        }
    });
    MaterialSpinner spinner2 = (MaterialSpinner) findViewById(R.id.spinner2);
    spinner2.setItems("Honda", "Yamaha", "Kawasaki", "Suzuki", "Lainnya");
    spinner2.setOnItemSelectedListener(new MaterialSpinner.OnItemSelectedListener<String>() {

        @Override public void onItemSelected(MaterialSpinner view, int position2, long id, String item) {
            //Snackbar.make(view, "Clicked " + item + position2, Snackbar.LENGTH_LONG).show();
            if (position2==0){
                MaterialSpinner spinner3 = (MaterialSpinner) findViewById(R.id.spinner3);
                spinner3.setItems("Revo 110 FI", "Blade 125 FI", "Supra X 125 FI");
                spinner3.setOnItemSelectedListener(new MaterialSpinner.OnItemSelectedListener<String>() {
                    @Override public void onItemSelected(MaterialSpinner view, int position, long id, String item) {
                        //Snackbar.make(view, "Clicked " + item, Snackbar.LENGTH_LONG).show();
                        if(position==0){
                            iritHonda=62200;
                        }else if(position==1){
                            iritHonda=61800;
                        }else if(position==2){
                            iritHonda=61800;
                        }
                    }
                });

            }
        }
    });
    totalHarga=iritHonda*hargaBBM;
    TextView Harga=(TextView)findViewById(R.id.totalHarga);
    Harga.setText(Double.toString(totalHarga));

}

}

Answer 1

您的问题是这些函数是回调。选择项目后，将异步调用它们。它们不返回值。在实际调用它们之前，不能使用它们设置的变量。这意味着所有在onCreate末尾使用它们的代码都位于错误的位置，需要在两个微调程序的处理程序内部调用它（因此，当任何一个微调程序更改时，它都可以更改）。

如何从java的If语句中的变量中获取值

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