计算器功能

Question

我试图获得简单的按钮总和的计算器功能。在这一个文本字段中将显示一个接一个地用+符号分隔的数字，一个计算按钮将显示结果。我被困在找ans()函数中的总和。请帮忙或建议。

我的Sum按钮调用功能sumclicked和Equals按钮调用result

public void result(View v) { // This will only display the resut

    TextView answer = (TextView)findViewById(R.id.output);
    answer.setText(String.valueOf(ans()));

}


public int ans()
{ // This is just for calculating the sum value to display
    int ans=0;

    int num2=0;

    int sum=sumclicked()+num2;
    num2=sum=ans;


    return ans;

     }


public void sumclicked (View v)
{ // This is display of textfield. Eg 55 + 12 + 99 

    EditText value=(EditText)findViewById(R.id.input);
    String ans=value.getText().toString();


    String ans1= ans +"+";

    TextView tempview = (TextView)findViewById(R.id.input);
    tempview.setText(ans1);

}

public int sumclicked()
{ // This parses each string digit to int and returns it for getting the summation done.

    EditText value=(EditText)findViewById(R.id.input);
    String ans=value.getText().toString();
    Integer ans1=Integer.parseInt(ans);
    return ans1;
}