在 android 中使用数字选择器添加或减去 TextView 的整数值

Question

我有两个数字选择器，例如：阅读数字选择器和诗歌数字选择器，每个学生默认获得 10 分，每当学生犯错时，数字选择器增加，分数应该减少（0.5）分，示例下面给出的代码，请帮助如何实现这个特定的方法。两个数字选择器都有递增和递减方法，两个数字选择器都应该增加或减少相同的文本视图，默认值为 10。

public class MainActivity extends AppCompatActivity {
    private NumberPicker readingPicker;
    private NumberPicker poempicker;
    private TextView pointsTextView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        readingPicker = findViewById(R.id.reading_picker);
        poempicker = findViewById(R.id.poem_picker);

        // increase or decrease value of points text view (10 default) using below number pickers.
        pointsTextView = findViewById(R.id.ten_points);

        readingPicker.setValueChangedListener(new ValueChangedListener() {
            @Override
            public void valueChanged(int value, ActionEnum action) {
                switch (action){
                    case INCREMENT:
                        // TODO: decrease value of pointsTextView by 0.5
                        break;
                    case DECREMENT:
                        // TODO: increase value of pointsTextView by 0.5

                }

            }
        });

        // after getting the value from above reading picker

        poempicker.setValueChangedListener(new ValueChangedListener() {
            @Override
            public void valueChanged(int value, ActionEnum action) {
                switch (action) {
                    case INCREMENT:
                        // TODO: decrease value of same pointsTextView by 0.5
                        break;
                    case DECREMENT:
                        // TODO: increase value of same pointsTextView by 0.5
                }


            }
        });
    }
}

我能够使用阅读数字选择器进行减法，但在那之后，我对如何获取 textview 的当前值并使用第二个数字选择器进一步减去有点困惑。

Answer 1

 readingPicker.setValueChangedListener(new ValueChangedListener() {
            @Override
            public void valueChanged(int value, ActionEnum action) {
                switch (action) {
                    case INCREMENT:
                        double currentValue = Double.parseDouble(pointsTextView.getText().toString());
                        currentValue = currentValue + 0.5;
                        pointsTextView.setText(String.valueOf(currentValue));
                        break;
                    case DECREMENT:
                        double currentValue1 = Double.parseDouble(pointsTextView.getText().toString());
                        currentValue1 = currentValue1 - 0.5;
                        pointsTextView.setText(String.valueOf(currentValue1));

                }

            }
        });

这样可以达到你想要的效果。获取 pointsTextView 的当前值，然后对其进行加减运算，然后再次将该值设置为 pointsTextView .

在 android 中使用数字选择器添加或减去 TextView 的整数值

Add or Subtract the Integer Value of TextView using Number Picker in android

android

increment

textview

decrement

numberpicker