计算器运算结果都是零
不管什么运算，点击等号 都是0，怎么解决啊？
Java4Android
2015-11-29
2 回答
为什么运行结果总是0呢，有时候还推出
package com.example.administrator.calculator;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
Button btn_0; //0数字按钮
Button btn_1; //1数字按钮
Button btn_2; //2数字按钮
Button btn_3; //3数字按钮
Button btn_4; //4数字按钮
Button btn_5; //5数字按钮
Button btn_6; //6数字按钮
Button btn_7; //7数字按钮
Button btn_8; //8数字按钮
Button btn_9; //9数字按钮
Button btn_point; //point按钮
Button btn_clear; //清除按钮
Button btn_del; //删除按钮
Button btn_plus; //加按钮
Button btn_minus; //减按钮
Button btn_multiply; //乘按钮
Button btn_divide; //除按钮
Button btn_equle; //等于按钮
EditText et_input; //显示输入的数字
boolean clear_flag;//清空标识
@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);
btn_clear = (Button) findViewById(R.id.btn_clear);
btn_del = (Button) findViewById(R.id.btn_del);
btn_plus = (Button) findViewById(R.id.btn_pluse);
btn_minus = (Button) findViewById(R.id.btn_minus);
btn_multiply = (Button) findViewById(R.id.btn_multiply);
btn_divide = (Button) findViewById(R.id.btn_divide);
btn_equle = (Button) findViewById(R.id.btn_equal);
//以上为实例化按钮
et_input = (EditText) findViewById(R.id.et_input);
//实例化显示屏
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_clear.setOnClickListener(this);
btn_del.setOnClickListener(this);
btn_plus.setOnClickListener(this);
btn_minus.setOnClickListener(this);
btn_multiply.setOnClickListener(this);
btn_divide.setOnClickListener(this);
btn_equle.setOnClickListener(this);
//以上为给按钮设置监听事件
et_input.setOnClickListener(this);
//以上为给文本框设置监听事件
}
@Override
public void onClick(View v) {
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_pluse:
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_clear:
clear_flag = false;
str = "";
et_input.setText(" ");
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_equal:
getResult();
default:
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(" "));//运算符前边的字符串
String op = exp.substring(exp.indexOf(" ")+1,exp.indexOf("")+2);//运算符
String s2 = exp.substring(exp.indexOf(" ")+3);//运算符后边的字串
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+"");
}
}else if (!s1.equals("")&&!s2.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("");
}
}
}
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