این سورس کدها:
Button btn0,btn1,btn2,btn3,btn4,btn5,btn6,btn7,btn8,btn9,btnDat,btnSum,btnMenha,btnTaghsim,
btnZarb,btnDeleteCalc,btnMosavi;
EditText txtNumbers;
String operation="";
Double Number1,Number2;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnstxt();
btn0.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
txtNumbers.setText(0);
}
});
btn1.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
txtNumbers.setText(1);
}
});
btn2.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
txtNumbers.setText(2);
}
});
btn3.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
txtNumbers.setText(3);
}
});
btn4.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
txtNumbers.setText(4);
}
});
btn5.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
txtNumbers.setText(5);
}
});
btn6.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
txtNumbers.setText(6);
}
});
btn7.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
txtNumbers.setText(7);
}
});
btn8.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
txtNumbers.setText(8);
}
});
btn9.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
txtNumbers.setText(2);
}
});
btnDat.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
txtNumbers.setText(".");
}
});
btnSum.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Number1=Double.parseDouble(txtNumbers.getText().toString());;
operation="+";
txtNumbers.setText("");
}
});
btnMenha.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Number1=Double.parseDouble(txtNumbers.getText().toString());;
operation="-";
txtNumbers.setText("");
}
});
btnTaghsim.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Number1=Double.parseDouble(txtNumbers.getText().toString());
operation="/";
txtNumbers.setText("");
}
});
btnZarb.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Number1=Double.parseDouble(txtNumbers.getText().toString());
operation="*";
txtNumbers.setText("");
}
});
btnDeleteCalc.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
txtNumbers.setText("");
}
});
}


@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);
}
///این تابع برای تعریف دقیق دکمه ها و یک جعبه متن بود
public void btnstxt() {
btn0=(Button)findViewById(R.id.btn0);
btn1=(Button)findViewById(R.id.btn1);
btn2=(Button)findViewById(R.id.btn2);
btn3=(Button)findViewById(R.id.btn3);
btn4=(Button)findViewById(R.id.btn4);
btn5=(Button)findViewById(R.id.btn5);
btn6=(Button)findViewById(R.id.btn6);
btn7=(Button)findViewById(R.id.btn7);
btn8=(Button)findViewById(R.id.btn8);
btn9=(Button)findViewById(R.id.btn9);
btnDat=(Button)findViewById(R.id.btnDat);
btnSum=(Button)findViewById(R.id.btnSum);
btnMenha=(Button)findViewById(R.id.btnMenha);
btnTaghsim=(Button)findViewById(R.id.btnTaghsim);
btnZarb=(Button)findViewById(R.id.btnZarb);
btnDeleteCalc=(Button)findViewById(R.id.btnDeleteCalc);
btnMosavi=(Button)findViewById(R.id.btnMosavi);
txtNumbers=(EditText)findViewById(R.id.txtNumbers);
}
}
ببخشید که همه رو کپی کردم،راستش برای اولین باره که این سوال رو میپرسم و لوگ ها هم نمیدونم کجاست که براتون بذارم.!!
این برنامه هیچ خطایی هم نداره.