单击按钮时的java选择方法

Question

我通过在计算equals按钮的情况下调用这些方法，对这些方法进行了单独测试。它们很好用。我的问题是确定是否按下了乘法或加法运算符，然后调用适当的方法

我在网上搜索了一下，并在case中使用了if语句来计算乘法：

case R.id.buttonequals:
    if (v.equals(btnmult)) {
        Multiplication();
    }

    else if (v.equals(btnplus)) {
        Addition();
    }
        break;

这不管用。这似乎很合乎逻辑。如果按下equal按钮，则根据按下的内容，将调用正确的方法。我的完整代码如下：

public class MainActivity extends Activity {
// variables declared to hold buttons and text field.
Button btn0, btn1, btn2, btn3, btn4, btn5, btn6, btn7, btn8, btn9, btnc,
    btnplus, btnd, btnpnt, btnequal, btnmult;
TextView text;
int num1, num2;
String input;

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

// reference and assign the resources for the view elements
btn0 = (Button) findViewById(R.id.button0);
btn1 = (Button) findViewById(R.id.button1);
btn2 = (Button) findViewById(R.id.button2);
btn3 = (Button) findViewById(R.id.button3);
btn4 = (Button) findViewById(R.id.button4);
btn5 = (Button) findViewById(R.id.button5);
btn6 = (Button) findViewById(R.id.button6);
btn7 = (Button) findViewById(R.id.button7);
btn8 = (Button) findViewById(R.id.button8);
btn9 = (Button) findViewById(R.id.button9);
btnc = (Button) findViewById(R.id.buttonc);
text = (TextView) findViewById(R.id.textView1);
btnd = (Button) findViewById(R.id.buttondel);
btnpnt = (Button) findViewById(R.id.buttonpnt);
btnplus = (Button) findViewById(R.id.buttonplus);
btnequal = (Button) findViewById(R.id.buttonequal);
btnmult = (Button) findViewById(R.id.buttonmult);

// add the click listeners
btn0.setOnClickListener(onClickListener);
btn1.setOnClickListener(onClickListener);
btn2.setOnClickListener(onClickListener);
btn3.setOnClickListener(onClickListener);
btn4.setOnClickListener(onClickListener);
btn5.setOnClickListener(onClickListener);
btn6.setOnClickListener(onClickListener);
btn7.setOnClickListener(onClickListener);
btn8.setOnClickListener(onClickListener);
btn9.setOnClickListener(onClickListener);
btnc.setOnClickListener(onClickListener);
btnd.setOnClickListener(onClickListener);
btnpnt.setOnClickListener(onClickListener);
btnplus.setOnClickListener(onClickListener);
btnequal.setOnClickListener(onClickListener);
btnmult.setOnClickListener(onClickListener);

}



private OnClickListener onClickListener = new OnClickListener() {

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub

    switch (v.getId()) {
    case R.id.button0:

        text.setText(text.getText().toString()
                + btn0.getText().toString());

        break;

    case R.id.button1:
        text.setText(text.getText().toString()
                + btn1.getText().toString());
        break;

    case R.id.button2:
        text.setText(text.getText().toString()
                + btn2.getText().toString());
        break;

    case R.id.button3:
        text.setText(text.getText().toString()
                + btn3.getText().toString());
        break;

    case R.id.button4:
        text.setText(text.getText().toString()
                + btn4.getText().toString());
        break;

    case R.id.button5:
        text.setText(text.getText().toString()
                + btn5.getText().toString());
        break;

    case R.id.button6:
        text.setText(text.getText().toString()
                + btn6.getText().toString());
        break;

    case R.id.button7:
        text.setText(text.getText().toString()
                + btn7.getText().toString());
        break;

    case R.id.button8:
        text.setText(text.getText().toString()
                + btn8.getText().toString());
        break;

    case R.id.button9:
        text.setText(text.getText().toString()
                + btn9.getText().toString());
        break;

    case R.id.buttondel:
        String contents = text.getText().toString();

        if (contents.length() > 1) {
            text.setText(contents.substring(0, contents.length() - 1));
        } else {
            text.setText("");
        }

        break;

    case R.id.buttonc:
        text.setText("");
        break;

    case R.id.button8:
        String dot = ".";
        String concat = text.getText() + dot;
        text.setText(concat);
        break;

    case R.id.buttonplus:

        num1 = Integer.parseInt(text.getText().toString());
        num2 = Integer.parseInt(text.getText().toString());
        text.setText(text.getText() + "+");
        break;

    case R.id.buttonmult:
        num1 = Integer.parseInt(text.getText().toString());
        num2 = Integer.parseInt(text.getText().toString());
        text.setText(text.getText() + "x");
        break;

    case R.id.buttonequals:
    if (v.equals(btnmult)) {
        Multiplication();
    }

    else if (v.equals(btnplus)) {
        Addition();
    }
        break;

    }
}

};

public void Addition() {
text.setText("");
int total = num1 + num2;
text.setText(Integer.toString(total));

}

public void Multiplication() {
text.setText("");
int total = num1 * num2;
text.setText(Integer.toString(total));

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

非常感谢您的帮助，如果解决方案过于明显，我深表歉意。谢谢大家抽出时间

Answer 1

为每个按钮（乘法、除法等）添加onClickListener

还为每个组件添加一个标志

 boolean multiply = false; //same for rest

当它们被点击时，你必须将其设置为真

 case R.id.multiply:
    multiply = true;

最后，当你点击=按钮的onClick事件时

 public void onClick(View v){
     ..
     case R.id.buttonequals:
        if (multiply) {
           Multiplication();
        }

        else if (other flags) {
          Addition();
        }
       break;
 }

Answer 2

为所有按钮设置相同的安卓：onClick，例如：“单击”

然后像这样使用：

public void clicking(View v) {
 Button button = (Button) v;
switch (button.getId()) {
case R.id.button0:

    text.setText(text.getText().toString()
            + btn0.getText().toString());

    break;

case R.id.button1:
    text.setText(text.getText().toString()
            + btn1.getText().toString());
    break;
and so on...