else有错 应该是符号问题 可是一直找不出
package com.example.activitydemo;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends Activity implements OnClickListener {
Button btn_0;
Button btn_1;
Button btn_2;
Button btn_3;
Button btn_4;
Button btn_5;
Button btn_6;
Button btn_7;
Button btn_8;
Button btn_9;
Button btn_point;// 小数点
Button btn_divide;// 除以
Button btn_multiply;// 乘以
Button btn_minus;// 减去
Button btn_pluse;// 加
Button btn_equal;// 等于
Button btn_clear;
Button btn_del;
EditText et_input;
boolean clear_flag;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn_0 = (Button) findViewById(R.id.btn_0);
btn_1 = (Button) findViewById(R.id.btn_1);
btn_2 = (Button) findViewById(R.id.btn_2);
btn_3 = (Button) findViewById(R.id.btn_3);
btn_4 = (Button) findViewById(R.id.btn_4);
btn_5 = (Button) findViewById(R.id.btn_5);
btn_6 = (Button) findViewById(R.id.btn_6);
btn_7 = (Button) findViewById(R.id.btn_7);
btn_8 = (Button) findViewById(R.id.btn_8);
btn_9 = (Button) findViewById(R.id.btn_9);
btn_point = (Button) findViewById(R.id.btn_point);// 小数点
btn_divide = (Button) findViewById(R.id.btn_divide);// 除以
btn_multiply = (Button) findViewById(R.id.btn_multiply);// 乘以
btn_minus = (Button) findViewById(R.id.btn_minus);// 减去
btn_pluse = (Button) findViewById(R.id.btn_plus);// 加
btn_equal = (Button) findViewById(R.id.btn_equals);// 等于
btn_clear = (Button) findViewById(R.id.btn_clear);
btn_del = (Button) findViewById(R.id.btn_del);
btn_0.setOnClickListener(this);
btn_1.setOnClickListener(this);
btn_2.setOnClickListener(this);
btn_3.setOnClickListener(this);
btn_4.setOnClickListener(this);
btn_5.setOnClickListener(this);
btn_6.setOnClickListener(this);
btn_7.setOnClickListener(this);
btn_8.setOnClickListener(this);
btn_9.setOnClickListener(this);
btn_point.setOnClickListener(this);
btn_divide.setOnClickListener(this);
btn_multiply.setOnClickListener(this);
btn_minus.setOnClickListener(this);
btn_pluse.setOnClickListener(this);
btn_equal.setOnClickListener(this);
btn_clear.setOnClickListener(this);
btn_del.setOnClickListener(this);
et_input = (EditText) findViewById(R.id.et_input);
}
@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);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String str = et_input.getText().toString();
switch (v.getId()) {
case R.id.btn_0:
case R.id.btn_1:
case R.id.btn_2:
case R.id.btn_3:
case R.id.btn_4:
case R.id.btn_5:
case R.id.btn_6:
case R.id.btn_7:
case R.id.btn_8:
case R.id.btn_9:
case R.id.btn_point:
if (clear_flag) {
clear_flag = false;
str = "";
et_input.setText("");
}
et_input.setText(str + ((Button) v).getText());
break;
case R.id.btn_plus:
case R.id.btn_minus:
case R.id.btn_multiply:
case R.id.btn_divide:
if (clear_flag) {
clear_flag = false;
str = "";
et_input.setText("");
}
et_input.setText(str + " " + ((Button) v).getText() + " ");
break;
case R.id.btn_del:
if (clear_flag) {
clear_flag = false;
str = "";
et_input.setText("");
} else if (str != null && !str.equals("")) {
et_input.setText(str.substring(0, str.length() - 1));
}
break;
case R.id.btn_clear:
clear_flag = false;
str = "";
et_input.setText("");
break;
case R.id.btn_equals:
getResult();
break;
}
}
private void getResult(){
String exp = et_input.getText().toString();
if(exp==null||exp.equals("")){
return;
}
if(!exp.contains(" ")){
return;
}
if(clear_flag){
clear_flag=false;
return;
}
clear_flag=true;
double result = 0;
String s1 = exp.substring(0,exp.indexOf(" "));
String op = exp.substring(exp.indexOf(" ")+1,exp.indexOf(" ")+2);
String s2 = exp.substring(exp.indexOf(" ")+3);
if(!s1.equals("")&&!s2.equals("")){
double d1=Double.parseDouble(s1);
double d2=Double.parseDouble(s2);
if(op.equals("+")){
result=d1+d2;
}
else if(op.equals("-")){
result=d1-d2;
}
else if(op.equals("×")){
result=d1*d2;
}
else if(op.equals("÷")){
if(d2==0)
result=0;
}
else {
result=d1/d2;
}
}
if(!s1.contains(".")&&!s2.contains(".")){
int r=(int)result;
et_input.setText(r+"");
}
else
{
et_input.setText(result+"");
}
}
String exp = et_input.getText().toString();
double result = 0;
String s1 = exp.substring(0,exp.indexOf(" "));
String op = exp.substring(exp.indexOf(" ")+1,exp.indexOf(" ")+2);
String s2 = exp.substring(exp.indexOf(" ")+3);
else if(!s1.equals("")&&s2.equals("")&&!op.equals("÷")){
et_input.setText(exp);
}
else if(s1.equals("")&&!s2.equals("")){
double d2=Double.parseDouble(s2);
if(op.equals("+")){
result=0+d2;
}
else if(op.equals("-")){
result=0-d2;
}
else if(op.equals("×")){
result=0;
}
else if(op.equals("÷")){
result=0;
}
if(s2.contains(".")){
int r=(int)result;
et_input.setText(r+"");
}
else
{
et_input.setText(result+"");
}
}
else
{
et_input.setText("");
}
}
}
问题1.......else一直错（只有else一个错)
问题2......我的exp.s1.s2.op都要定义两次 如图
问题1图
问题2图 看 我定义了两次 如果把第二次定义取消 后面的s1 s2 exp op 都会出错
谢谢大家
