如何在多个按钮上单击显示的 TextView 整数值相乘

Question

我有 10 个按钮和 2 列，例如 5x2。这 2 列包含带有 5 个按钮的循环，每个按钮的每列都有文本视图，当用户单击这 2 列的任何按钮时，将显示 2 个文本视图整数。我想将这些显示的数字相乘以获得第三个 Textview 中的最终结果，但它没有相乘，下面是我编写的代码：

public class MultiplicationActivity extends AppCompatActivity{
    private static final int[] column1_buttonsArrays = {R.id.column1_button0, R.id.column1_button1, R.id.column1_button2, R.id.column1_button3, R.id.column1_button4};
    private Button[] c1_buttons = new Button[column1_buttonsArrays.length];
    int i1;
    private static final int[] column2_buttonsArrays = {R.id.column2_button0, R.id.column2_button1, R.id.column2_button2, R.id.column2_button3, R.id.column2_button4};
    private Button[] c2_buttons = new Button[column2_buttonsArrays.length];
    int i2;
    int num1, num2, solution1;
    @Override
        protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.multiplication);
        
           dummyTextValue1 = findViewById(R.id.dummy_value1);
           dummyTextValue2 = findViewById(R.id.dummy_value2);
           multipliedText = findViewById(R.id.multiplied_value);
        
           for(i1 = 0; i1 < column1_buttonsArrays.length; i1++) {
           c1_buttons[i1] = findViewById(column1_buttonsArrays[i1_buttons]);
           c1_buttons[i1].setOnClickListener(new View.OnClickListener() {
           @Override
             public void onClick(View view) {
             switch (view.getId()) {
             case R.id.column1_button0:
                 dummyTextValue1.setText("0");
                 break;
             case R.id.column1_button1:
                 dummyTextValue1.setText("1");
                 break;
             case R.id.column1_button2:
                 dummyTextValue1.setText("2");
                 break;
             case R.id.column1_button3:
                 dummyTextValue1.setText("3");
                 break;
             case R.id.column1_button4:
                 dummyTextValue1.setText("4");
                 break;
                }
            }
        });
    }
            for(i2 = 0; i2 < column2_buttonsArrays.length; i2++) {
            c2_buttons[i2] = findViewById(column2_buttonsArrays[i2_buttons]);
            c2_buttons[i2].setOnClickListener(new View.OnClickListener() {
            @Override
              public void onClick(View view) {
              switch (view.getId()) {
             case R.id.column2_button0:
                 dummyTextValue2.setText("0");
                 break;
             case R.id.column2_button1:
                 dummyTextValue2.setText("1");
                 break;
             case R.id.column2_button2:
                 dummyTextValue2.setText("2");
                 break;
             case R.id.column2_button3:
                 dummyTextValue2.setText("3");
                 break;
             case R.id.column2_button4:
                 dummyTextValue2.setText("4");
                 break;
                }
            }
        });
    }
    String value1 = dummyTextValue1.getText().toString();
    String value2 = dummyTextValue2.getText().toString();
    num1 = Integer.parseInt(value1);
    num2 = Integer.parseInt(value2);
    solution1 = (int) (num1 * num2);
    multipliedText.setText(solution1);
  }
}

不明白我哪里做错了。请给我一个想法或更新的代码，说明如何从 for 循环中获取乘以显示的值。提前致谢..

Answer 1

问题是您的 solution 变量是一个整数。 solution1 = (int) (num1 * num2);

在android中，TextView.setText(int resource)可以用来在TextView中设置一个String资源。您将要使用 TextView.setText(String text)。检查 documentation

你可以这样做：

multipliedText.setText(String.valueOf(solution1));

另一个问题是 multipliedText.setText() 在 Activity 创建后立即执行。例如。两个 dummyValues 都将为空。单击按钮后，您需要执行此行。

像这样：

dummyTextValue1.setOnClickListener(new View.OnClickListener(){
    @Override
    public void onClick(View v) {
        switch (view.getId()) {
             //..
        }

        String value1 = dummyTextValue1.getText().toString();
        String value2 = dummyTextValue2.getText().toString();
        updateText(value1, value2);
   }
});

private void updateText(String value1, String value2, TextView textView) {

    num1 = Integer.parseInt(value1);
    num2 = Integer.parseInt(value2);
    solution1 = (int) (num1 * num2);
    textView.setText(String.valueOf(solution1));
}

这将在每次单击其中一个按钮时调用 updateText，从而更新您的文本。祝你好运

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