Question

我正在创建一个应用程序，其中三个cell?.imageView?.image = UIImage(named: "Default")和三个tabs为三个选项卡分别创建，三个选项卡代表bmi计算器，长度转换器和重量转换器。没有任何计算按钮可以在任何片段中使用

我尝试从fragments设置onclick，并且覆盖xml文件中的onclick方法

fragment.java

我希望从@Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Inflate the layout for this fragment return inflater.inflate(R.layout.fragment_fragment_1, container, false); } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); height = height.findViewById(R.id.height); weight = weight.findViewById(R.id.weight); result = result.findViewById(R.id.result); calc = calc.findViewById(R.id.calc); calc.setOnClickListener(new View.OnClickListener() { String heightStr = height.getText().toString(); String weightStr = weight.getText().toString(); @Override public void onClick(View arg0) { // here you set what you want to do when user clicks your button, // e.g. launch a new activity if (Objects.equals(heightStr, "") || !Objects.equals(weightStr, "")) { float heightValue = Float.parseFloat(heightStr); float weightValue = Float.parseFloat(weightStr); float bmi = weightValue / (heightValue * heightValue); displayBMI(bmi); } else { result.setText(getString(R.string.Enter_height)); } } private void displayBMI(float bmi) { String bmiLabel; if (Float.compare(bmi, 15f) <= 0) { bmiLabel = getString(R.string.severely_underweight); } else if (Float.compare(bmi, 15f) > 0 && Float.compare(bmi, 16f) <= 0) { bmiLabel = getString(R.string.very_underweight); } else if (Float.compare(bmi, 16f) > 0 && Float.compare(bmi, 18.5f) <= 0) { bmiLabel = getString(R.string.underweight); } else if (Float.compare(bmi, 18.5f) > 0 && Float.compare(bmi, 25f) <= 0) { bmiLabel = getString(R.string.normal_weight); } else if (Float.compare(bmi, 25f) > 0 && Float.compare(bmi, 30f) <= 0) { bmiLabel = getString(R.string.over_weight); } else if (Float.compare(bmi, 30f) > 0 && Float.compare(bmi, 35f) <= 0) { bmiLabel = getString(R.string.first_class_obese); } else if (Float.compare(bmi, 35f) > 0 && Float.compare(bmi, 40f) <= 0) { bmiLabel = getString(R.string.second_class_obese); } else { bmiLabel = getString(R.string.third_class_obese); } bmiLabel = bmi + "\n" + bmiLabel; result.setText(bmiLabel); } }) ; }和button: "@id calc"的{{1}}字段中输入的值中单击editText来计算bmi

Answer 1

您的代码有一些错误。在不更改代码逻辑的情况下，我已将其修复。

由于您提供的详细信息还不够，因此我不得不在这里假设一些事情，

变量result在片段的XML文件中的类型为TextView，其ID为result。
变量height，weight在您的Fragment的XML文件中的类型为EditText（如上所述），其ID为height和weight。
变量calc在片段的XML文件中的类型为Button，其ID为calc。

您的应用程序中的Objects是什么？我看不到它的声明或在哪里初始化。除非我们知道它是什么，否则不初始化此代码将不起作用

String heightStr;
String weightStr;

EditText height;
EditText weight;
TextView result;

Button calc;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle 
savedInstanceState) {

    View view = inflater.inflate(R.layout.fragment_fragment_1, container, false);

    height = (EditText) view.findViewById(R.id.height);
    weight = (EditText) view.findViewById(R.id.weight);

    result = (TextView) view.findViewById(R.id.result);

    calc = (Button) view.findViewById(R.id.calc);

    calc.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // here you set what you want to do when user clicks your button,
            // e.g. launch a new activity

            heightStr = height.getText().toString();
            weightStr = weight.getText().toString();

            if (Objects.equals(heightStr, "") || !Objects.equals(weightStr, "")) {
                float heightValue = Float.parseFloat(heightStr);
                float weightValue = Float.parseFloat(weightStr);
                float bmi = weightValue / (heightValue * heightValue);
                displayBMI(bmi);
            } else {
                result.setText(getString(R.string.Enter_height));
            }
        }
    });
    return view;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}


private void displayBMI(float bmi) {

    String bmiLabel;

    if (Float.compare(bmi, 15f) <= 0) {
        bmiLabel = getString(R.string.severely_underweight);
    } else if (Float.compare(bmi, 15f) > 0 && Float.compare(bmi, 16f) <= 0) {
        bmiLabel = getString(R.string.very_underweight);
    } else if (Float.compare(bmi, 16f) > 0 && Float.compare(bmi, 18.5f) <= 0) {
        bmiLabel = getString(R.string.underweight);
    } else if (Float.compare(bmi, 18.5f) > 0 && Float.compare(bmi, 25f) <= 0) {
        bmiLabel = getString(R.string.normal_weight);
    } else if (Float.compare(bmi, 25f) > 0 && Float.compare(bmi, 30f) <= 0) {
        bmiLabel = getString(R.string.over_weight);
    } else if (Float.compare(bmi, 30f) > 0 && Float.compare(bmi, 35f) <= 0) {
        bmiLabel = getString(R.string.first_class_obese);
    } else if (Float.compare(bmi, 35f) > 0 && Float.compare(bmi, 40f) <= 0) {
        bmiLabel = getString(R.string.second_class_obese);
    } else {
        bmiLabel = getString(R.string.third_class_obese);
    }

    bmiLabel = bmi + "\n" + bmiLabel;
    result.setText(bmiLabel);

}

Answer 2

尝试在按钮单击时在Xml中添加onClick方法。

android:onClick="onButtonClick"

在片段内部创建与XML中提到的方法相同的方法。

public void onButtonClick(View view){
    //add your code here.
}

如何在选项卡式活动的片段中获取“计算按钮”

2 个答案: