Question

我正在研究简单的计算器程序。我试着编写一个代码，它会返回我按下的按钮的ID（+， - ，*或/）。

我做了什么，我使用了2个TEXTBOX，其中一个将保留一个数字＆amp; ＆＃34; =＆＃34;按钮会做数学＆amp;在TX1上显示结果。我试着使用SWITCH选项。出于某种原因，当我按下＆＃34; =＆＃34;它没有用。

我将感谢你们的帮助。

import android.app.Activity;  
import android.content.Intent;  
import android.os.Bundle;  
import android.view.Menu;  
import android.view.MenuItem;  
import android.view.View;  
import android.widget.Button;  
import android.widget.TextView;

public class MainActivity extends Activity implements android.view.View.OnClickListener {  
private Button B1,B2,B3,B4,B5,B6,B7,B8,B9,B0;   
private Button BMINUS,BSHAVE,BDIVIDE,BBACK,BCLEAR,BPOINT,BDUAL,BPLUS;  
private TextView TVDISPLAY,TVDISPLAY2;  
double x=0,y=0,z=0;


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

    B1 = (Button) findViewById(R.id.bt1);
    B1.setOnClickListener(this);
    B2 = (Button) findViewById(R.id.bt2);
    B2.setOnClickListener(this);
    B3 = (Button) findViewById(R.id.bt3);
    B3.setOnClickListener(this);
    B4 = (Button) findViewById(R.id.bt4);
    B4.setOnClickListener(this);
    B5 = (Button) findViewById(R.id.bt5);
    B5.setOnClickListener(this);
    B6 = (Button) findViewById(R.id.bt6);
    B6.setOnClickListener(this);
    B7 = (Button) findViewById(R.id.bt7);
    B7.setOnClickListener(this);
    B8 = (Button) findViewById(R.id.bt8);
    B8.setOnClickListener(this);
    B9 = (Button) findViewById(R.id.bt9);
    B9.setOnClickListener(this);
    B0 = (Button) findViewById(R.id.bt0);
    B0.setOnClickListener(this);
    BMINUS = (Button) findViewById(R.id.btsub);
    BMINUS.setOnClickListener(this);
    BSHAVE = (Button) findViewById(R.id.btequal);
    BSHAVE.setOnClickListener(this);
    BPLUS= (Button) findViewById(R.id.btadd);
    BPLUS.setOnClickListener(this);
    BDIVIDE= (Button) findViewById(R.id.btdivide);
    BDIVIDE.setOnClickListener(this);
    BBACK= (Button) findViewById(R.id.btback);
    BBACK.setOnClickListener(this);
    BCLEAR = (Button) findViewById(R.id.btclear);
    BCLEAR.setOnClickListener(this);
    BPOINT = (Button) findViewById(R.id.btpoint);
    BPOINT.setOnClickListener(this);
    BDUAL = (Button) findViewById(R.id.btdual);
    BDUAL.setOnClickListener(this);
    TVDISPLAY = (TextView) findViewById(R.id.TV1);
    TVDISPLAY.setOnClickListener(this);
    TVDISPLAY.setText(" ");
    TVDISPLAY.setVisibility(View.VISIBLE); // textview visible
    TVDISPLAY2 = (TextView) findViewById(R.id.TV2);
    TVDISPLAY2.setOnClickListener(this);
    TVDISPLAY2.setText(" ");
    TVDISPLAY2.setVisibility(View.INVISIBLE); // textview2 invisible

}

@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;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

public void OnClickListener(){

}

@Override
public void onClick(View v) {       

     final int id = v.getId();
        switch (id) {
        case R.id.bt0:             
            if (TVDISPLAY.getVisibility() == View.VISIBLE) {
            TVDISPLAY.setText(TVDISPLAY.getText() + "0");   
            }
            else {
                TVDISPLAY2.setText(TVDISPLAY2.getText() + "0"); 
            }
            break;
        case R.id.bt1:         
            if (TVDISPLAY.getVisibility() == View.VISIBLE) {
                TVDISPLAY.setText(TVDISPLAY.getText() + "1");   
                }
                else {
                    TVDISPLAY2.setText(TVDISPLAY2.getText() + "1"); 
                }
                break;              
        case R.id.bt2:
            if (TVDISPLAY.getVisibility() == View.VISIBLE) {
                TVDISPLAY.setText(TVDISPLAY.getText() + "2");   
                }
                else {
                    TVDISPLAY2.setText(TVDISPLAY2.getText() + "2"); 
                }
                break;
        case R.id.bt3:
            if (TVDISPLAY.getVisibility() == View.VISIBLE) {
                TVDISPLAY.setText(TVDISPLAY.getText() + "3");   
                }
                else {
                    TVDISPLAY2.setText(TVDISPLAY2.getText() + "3"); 
                }
                break;
        case R.id.bt4:
            if (TVDISPLAY.getVisibility() == View.VISIBLE) {
                TVDISPLAY.setText(TVDISPLAY.getText() + "4");   
                }
                else {
                    TVDISPLAY2.setText(TVDISPLAY2.getText() + "4"); 
                }
                break;
        case R.id.bt5:
            if (TVDISPLAY.getVisibility() == View.VISIBLE) {
                TVDISPLAY.setText(TVDISPLAY.getText() + "5");   
                }
                else {
                    TVDISPLAY2.setText(TVDISPLAY2.getText() + "5"); 
                }
                break;
        case R.id.bt6:
            if (TVDISPLAY.getVisibility() == View.VISIBLE) {
                TVDISPLAY.setText(TVDISPLAY.getText() + "6");   
                }
                else {
                    TVDISPLAY2.setText(TVDISPLAY2.getText() + "6"); 
                }
                break;
        case R.id.bt7:
            if (TVDISPLAY.getVisibility() == View.VISIBLE) {
                TVDISPLAY.setText(TVDISPLAY.getText() + "7");   
                }
                else {
                    TVDISPLAY2.setText(TVDISPLAY2.getText() + "7"); 
                }
                break;
        case R.id.bt8:
            if (TVDISPLAY.getVisibility() == View.VISIBLE) {
                TVDISPLAY.setText(TVDISPLAY.getText() + "8");   
                }
                else {
                    TVDISPLAY2.setText(TVDISPLAY2.getText() + "8"); 
                }
                break;
        case R.id.bt9:
            if (TVDISPLAY.getVisibility() == View.VISIBLE) {
                TVDISPLAY.setText(TVDISPLAY.getText() + "9");   
                }
                else {
                    TVDISPLAY2.setText(TVDISPLAY2.getText() + "9"); 
                }
                break;
        case R.id.btadd: // add function
            AddFunc(x);                         break;
        case R.id.btclear: // clear
            TVDISPLAY.setText(" "); 
            TVDISPLAY2.setText(" ");            break;
        case R.id.btback: // back
            BackFunc();                         break;
        case R.id.btdivide: // divide
            DevFunc(id);                        break;      
        case R.id.btdual: // Kefel
            DualFuncdual(id);                   break;
        case R.id.btequal: // Shave             
            EqualFunc(v);                   break;
        case R.id.btpoint: // Nekuda
            TVDISPLAY.setText(TVDISPLAY.getText() + ".");   
            Nekuda();                           break;// will check if there is a point in the number
        case R.id.btsub: // Sub
            SubFunc(id);

            Intent intent = new Intent(this,MainActivity.class);
            intent = intent.putExtra("TVDISPLAY", TVDISPLAY.getText().toString());

        }       
}   

private double EqualFunc(View v) { 
    // will get the id of the button that pressed
    // check which button is pressed by id.
    Button clickedButton = (Button) v;
    switch (clickedButton.getId()) {

    case R.id.btadd:    // add        
        y=Double.parseDouble(TVDISPLAY2.getText().toString());      
        z=x+y;     
            TVDISPLAY.setVisibility(View.VISIBLE);
            TVDISPLAY2.setVisibility(View.INVISIBLE);
            TVDISPLAY.setText(Double.toString(z));

    break;

    case R.id.btsub:     // sub

        y=Double.parseDouble(TVDISPLAY2.getText().toString());      
    z=x-y;     
        TVDISPLAY.setVisibility(View.VISIBLE);
        TVDISPLAY2.setVisibility(View.INVISIBLE);
        TVDISPLAY.setText(Double.toString(z));
    break;

    case R.id.btdual: // dual

        y=Double.parseDouble(TVDISPLAY2.getText().toString());      
        z=x*y;     
        TVDISPLAY.setVisibility(View.VISIBLE);
        TVDISPLAY2.setVisibility(View.INVISIBLE);
        TVDISPLAY.setText(Double.toString(z));

    break;

    case (R.id.btdivide):    // divide

        y=Double.parseDouble(TVDISPLAY2.getText().toString());      
        z=x/y;     
        TVDISPLAY.setVisibility(View.VISIBLE);
        TVDISPLAY2.setVisibility(View.INVISIBLE);
        TVDISPLAY.setText(Double.toString(z));
    }
    return z;       
}

private double SubFunc(double x2) { // still empty

    x=Double.parseDouble(TVDISPLAY.getText().toString());
    TVDISPLAY.setVisibility(View.INVISIBLE);
    TVDISPLAY2.setVisibility(View.VISIBLE);
    return R.id.btsub;  
}

private double DevFunc(double x2) {// still empty
    x=Double.parseDouble(TVDISPLAY.getText().toString());
    TVDISPLAY.setVisibility(View.INVISIBLE);
    TVDISPLAY2.setVisibility(View.VISIBLE);
    return R.id.btdivide;
}   

private double DualFuncdual(double x2) {            
    x=Double.parseDouble(TVDISPLAY.getText().toString());
    TVDISPLAY.setVisibility(View.INVISIBLE);
    TVDISPLAY2.setVisibility(View.VISIBLE);
    return R.id.btdual;
}

private double AddFunc( double x2) { // doesn't work.
    x=Double.parseDouble(TVDISPLAY.getText().toString());
    TVDISPLAY.setVisibility(View.INVISIBLE);
    TVDISPLAY2.setVisibility(View.VISIBLE);
    return x;
}

}

Answer 1

尝试声明android：onClick =“btn1”或btn2或btn3等......

要获得他们的功能，您需要做的就是声明

public void btn1（查看v）

{

//在这里运作

}

Answer 2

您可以尝试Mike发布的代码。或者你可以这样做：

clickedButton.setOnClickListener(new View.OnClickListener() {
         public void onClick(View v) {
             // Perform action on click
         }
     });

每次按下按钮＆＃39;点击按钮＆＃39;单击，方法＆＃39; onClick（查看v）＆＃39;被称为

或者你可以实现界面＆＃39; OnClickListener＆＃39;在你的课堂上，将听众注册到你的班级，如下所示：

 clickedButton.setOnClickListener(this);

然后，关于方法＆＃39; public void onClick（View v）＆＃39;你可以这样做：

public void onClick(View v) {
   switch(v.getId()){
    case R.id.clickedButtonId :
      //Do Stuff
      break;

    default:
      break;
   }
}

如何找到按下哪个按钮？（android）

2 个答案: