今天小编给大家分享一下Android如何实现房贷计算器的相关知识点，内容详细，逻辑清晰，相信大部分人都还太了解这方面的知识，所以分享这篇文章给大家参考一下，希望大家阅读完这篇文章后有所收获，下面我们一起来了解一下吧。
fangdai（activity）
package com.example.myapplication_one;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.text.Editable;import android.text.TextUtils;import android.text.TextWatcher;import android.view.View;import android.widget.ArrayAdapter;import android.widget.Button;import android.widget.CheckBox;import android.widget.EditText;import android.widget.RadioGroup;import android.widget.Spinner;import android.widget.TextView;import android.widget.Toast;public class fangdai extends AppCompatActivity { //声明用到的所有控件 Spinner spinner1; Spinner spinner2; EditText row1edit; EditText row2edit; Button total; RadioGroup radioGroup; CheckBox checkBox1; CheckBox checkBox2; EditText row4edit; EditText row5edit; Button detail; TextView totalcal; TextView alldetail; private void initSpinner(){ //初始化控件 spinner1= (Spinner) findViewById(R.id.sp1); spinner2= (Spinner) findViewById(R.id.sp2); //建立数据源 String[] years=getResources().getStringArray(R.array.years); String[] baserates=getResources().getStringArray(R.array.baserate); //声明一个下拉列表的数组适配器并绑定数据源 ArrayAdapter<String> yearAdapter=new ArrayAdapter<String>(this,R.layout.support_simple_spinner_dropdown_item,years); ArrayAdapter<String> baserateAdapter=new ArrayAdapter<String>(this,R.layout.support_simple_spinner_dropdown_item,baserates); //绑定Adapter到控件 spinner1.setAdapter(yearAdapter); spinner2.setAdapter(baserateAdapter); //设置默认选择第一项 spinner1.setSelection(0); spinner2.setSelection(0); //设置 spinner1.setPrompt("请选择贷款年限"); spinner2.setPrompt("请选择基准利率"); } //声明下列函数中要用到的变量 double intotal,backtotal,extra,pertime;//贷款总额，还款总额，利息，每月还款总额 int month;//月份 String buytotal;//购房总额 String percent;//贷款百分比 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.fangdai); //初始化控件 initSpinner(); row1edit= (EditText) findViewById(R.id.row1edit); row2edit= (EditText) findViewById(R.id.row2edit); total= (Button) findViewById(R.id.totalcal); radioGroup= (RadioGroup) findViewById(R.id.radiogroup); checkBox1= (CheckBox) findViewById(R.id.check1); checkBox2= (CheckBox) findViewById(R.id.check2); totalcal= (TextView) findViewById(R.id.showtotal); detail= (Button) findViewById(R.id.detail); alldetail= (TextView) findViewById(R.id.alldetail); row4edit= (EditText) findViewById(R.id.row4label); row5edit= (EditText) findViewById(R.id.row5label); //给第一个计算按钮添加点击监听 total.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { buytotal=row1edit.getText().toString(); percent=row2edit.getText().toString(); if(TextUtils.isEmpty(buytotal)||TextUtils.isEmpty(percent))//判断前两个输入框是否非空 { Toast.makeText(fangdai.this,"购房总价和按揭部分信息填写完整",Toast.LENGTH_LONG).show(); }else if(fangdaitext.isNum(buytotal)==false||fangdaitext.isNum(percent)==false){//判断输入的是否是数字 Toast.makeText(fangdai.this,"包含不合法的输入信息",Toast.LENGTH_LONG).show(); } else if(Double.parseDouble(percent)>100){//判断百分比部分输入是否大于100% Toast.makeText(fangdai.this,"按揭部分不能超过100%",Toast.LENGTH_LONG).show(); } else if(fangdaitext.isNum(buytotal)&&fangdaitext.isNum(percent)) { intotal=(Double.parseDouble(buytotal)*Double.parseDouble(percent)*0.01); totalcal.setText("您的贷款总额为"+String.format("%.2f",intotal)+"万元"); } } }); detail.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { //first,second为商贷和公积金贷所填数值 String first=row4edit.getText().toString(); String second=row5edit.getText().toString(); //firstrate和secondrate为商贷和公积金的年利率 double firstrate=Double.parseDouble(spinner2.getSelectedItem().toString().substring(20,24))*0.01; double secondrate=Double.parseDouble(spinner2.getSelectedItem().toString().substring(31,35))*0.01; //获取下拉列表的年份求得月份 String year=spinner1.getSelectedItem().toString(); month=Integer.parseInt(year.substring(0,year.length()-1))*12; //两种贷款的月利率 double firstmonthrate=firstrate/12; double secondmonthrate=secondrate/12; if(totalcal.getText().toString().equals("其中贷款部分为：***万")){//判断是否计算过贷款总额 Toast.makeText(fangdai.this,"请先计算贷款总额",Toast.LENGTH_LONG).show(); }else if(row1edit.getText().toString().equals(buytotal)==false||row2edit.getText().toString().equals(percent)==false){//监听贷款总额和按揭部分数值是否发生变化 Toast.makeText(fangdai.this,"检查到您的购房总价或按揭部分数据更改，请重新计算贷款总额",Toast.LENGTH_LONG).show(); } else if(checkBox1.isChecked()==false&&checkBox2.isChecked()==false)//监听勾选的多选框 { Toast.makeText(fangdai.this,"请勾选贷款种类",Toast.LENGTH_LONG).show(); }else if(checkBox1.isChecked()&&checkBox2.isChecked()==false){ //等额本息贷款算法 if(radioGroup.getCheckedRadioButtonId()==R.id.btn1){ pertime=intotal*firstmonthrate*Math.pow((1+firstmonthrate),month)/(Math.pow(1+firstmonthrate,month)-1); backtotal=pertime*month; extra=backtotal-intotal; alldetail.setText("您的贷款总额为"+String.format("%.2f",intotal)+"万元\n还款总额为"+String.format("%.2f",backtotal)+"万元\n其中利息总额为"+String.format("%.2f",extra)+"万元\n还款总时间为"+month+"月\n每月还款金额为"+String.format("%.2f",pertime*10000)+"元"); }else{//等额本金贷款算法 double[] array=new double[month]; double sum=0; for(int i=0;i<month;i++) { array[i]=intotal/month+(intotal-sum)*firstmonthrate; sum+=array[i]; } String text=""; for(int i=0;i<month;i++){ text+="\n第"+(i+1)+"个月应还金额为："+String.format("%.2f",array[i]*10000); } backtotal=sum; extra=backtotal-intotal; alldetail.setText("您的贷款总额为"+String.format("%.2f",intotal)+"万元\n还款总额为"+String.format("%.2f",backtotal)+"万元\n其中利息总额为"+String.format("%.2f",extra)+"万元\n还款总时间为"+month+"月\n每月还款金额如下："+text); } }else if(checkBox1.isChecked()==false&&checkBox2.isChecked()){ if(radioGroup.getCheckedRadioButtonId()==R.id.btn1){ pertime=intotal*secondmonthrate*Math.pow((1+secondmonthrate),month)/(Math.pow(1+secondmonthrate,month)-1); backtotal=pertime*month; extra = backtotal - intotal; alldetail.setText("您的贷款总额为" + String.format("%.2f",intotal) + "万元\n还款总额为"+String.format("%.2f",backtotal)+"万元\n其中利息总额为"+String.format("%.2f",extra)+"万元\n还款总时间为"+month+"月\n每月还款金额为"+String.format("%.2f",pertime*10000)+"元"); }else{ double[] array=new double[month]; double sum=0; for(int i=0;i<month;i++) { array[i]=intotal/month+(intotal-sum)*secondmonthrate; sum+=array[i]; } String text=""; for(int i=0;i<month;i++){ text+="\n第"+(i+1)+"个月应还金额为："+String.format("%.2f",array[i]*10000)+"元"; } backtotal=sum; extra=backtotal-intotal; alldetail.setText("您的贷款总额为"+String.format("%.2f",intotal)+"万元\n还款总额为"+String.format("%.2f",backtotal)+"万元\n其中利息总额为"+String.format("%.2f",extra)+"万元\n还款总时间为"+month+"月\n每月还款金额如下："+text); } }else if(checkBox1.isChecked()&&checkBox2.isChecked()){ if(radioGroup.getCheckedRadioButtonId()==R.id.btn1){ if(TextUtils.isEmpty(first)||TextUtils.isEmpty(second)){ Toast.makeText(fangdai.this,"请将空信息填写完整",Toast.LENGTH_LONG).show(); }else if(fangdaitext.isNum(first)==false||fangdaitext.isNum(second)==false){ Toast.makeText(fangdai.this,"包含不合法的输入信息",Toast.LENGTH_LONG).show(); }else if(Double.parseDouble(first)+Double.parseDouble(second)!=Double.parseDouble(String.format("%.2f",intotal))){ Toast.makeText(fangdai.this,"填写的两项贷款总额不等于初始贷款额度，请重新填写",Toast.LENGTH_LONG).show(); }else{ double p1=Double.parseDouble(first); double p2=Double.parseDouble(second); double pertime1=p1*firstmonthrate*Math.pow((1+firstmonthrate),month)/(Math.pow(1+firstmonthrate,month)-1); double pertime2=p2*secondmonthrate*Math.pow((1+secondmonthrate),month)/(Math.pow(1+secondmonthrate,month)-1); pertime=pertime1+pertime2; backtotal=pertime*month; extra=backtotal-intotal; alldetail.setText("您的贷款总额为" + String.format("%.2f",intotal) + "万元\n还款总额为"+String.format("%.2f",backtotal)+"万元\n其中利息总额为"+String.format("%.2f",extra)+"万元\n还款总时间为"+month+"月\n每月还款金额为"+String.format("%.2f",pertime*10000)+"元"); } }else{ if(first.equals("请输入商业贷款总额（单位万）")||second.equals("请输入公积金贷款总额（单位万）")){ Toast.makeText(fangdai.this,"请将空信息填写完整",Toast.LENGTH_LONG).show(); }else if(fangdaitext.isNum(first)==false||fangdaitext.isNum(second)==false){ Toast.makeText(fangdai.this,"包含不合法的输入信息",Toast.LENGTH_LONG).show(); }else if(Double.parseDouble(first)+Double.parseDouble(second)!=Double.parseDouble(String.format("%.2f",intotal))){ Toast.makeText(fangdai.this,"填写的两项贷款总额不等于初始贷款额度，请重新填写",Toast.LENGTH_LONG).show(); }else{ double p1=Double.parseDouble(first); double p2=Double.parseDouble(second); double[] array1=new double[month]; double[] array2=new double[month]; double sum1=0,sum2=0; for(int i=0;i<month;i++) { array1[i]=p1/month+(p1-sum1)*firstmonthrate; array2[i]=p2/month+(p2-sum2)*secondmonthrate; Toast.makeText(fangdai.this,array1[i]+" "+array2[i],Toast.LENGTH_LONG); sum1+=array1[i]; sum2+=array2[i]; } String text=""; for(int i=0;i<month;i++){ text+="\n第"+(i+1)+"个月应还金额为："+String.format("%.2f",(array1[i]+array2[i])*10000)+"元"; } backtotal=sum1+sum2; extra=backtotal-intotal; alldetail.setText("您的贷款总额为"+String.format("%.2f",intotal)+"万元\n还款总额为"+String.format("%.2f",backtotal)+"万元\n其中利息总额为"+String.format("%.2f",extra)+"万元\n还款总时间为"+month+"月\n每月还款金额如下："+text); } } } } }); row1edit.addTextChangedListener(new TextWatcher() { int oldlength=0; @Override public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) { } @Override public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {//强制用户不能输入非数字和小数点之外的字符 int length = charSequence.length(); if (length > oldlength) { char newchar = charSequence.charAt(i); if ((newchar < '0' && newchar > '9') && newchar != '.') { if (i != length - 1) row1edit.setText(charSequence.subSequence(0, i).toString() + charSequence.subSequence(i + 1, length).toString()); else row1edit.setText(charSequence.subSequence(0, length - 1)); } } oldlength=length; } @Override public void afterTextChanged(Editable editable) { } }); row2edit.addTextChangedListener(new TextWatcher() { int oldlength=0; @Override public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) { } @Override public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) { int length=charSequence.length(); if(length>oldlength) { char newchar = charSequence.charAt(i); if ((newchar < '0' && newchar > '9') && newchar != '.') { if (i != length - 1) row2edit.setText(charSequence.subSequence(0, i).toString() + charSequence.subSequence(i + 1, length).toString()); else row2edit.setText(charSequence.subSequence(0, length - 1)); } } oldlength=length; } @Override public void afterTextChanged(Editable editable) { } }); row4edit.addTextChangedListener(new TextWatcher() { int oldlength=0; @Override public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) { } @Override public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) { int length=charSequence.length(); if(length>oldlength) { char newchar = charSequence.charAt(i); if ((newchar < '0' && newchar > '9') && newchar != '.') { if (i != length - 1) row4edit.setText(charSequence.subSequence(0, i).toString() + charSequence.subSequence(i + 1, length).toString()); else row4edit.setText(charSequence.subSequence(0, length - 1)); } } oldlength=length; } @Override public void afterTextChanged(Editable editable) { } }); row5edit.addTextChangedListener(new TextWatcher() { int oldlength=0; @Override public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) { } @Override public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) { int length=charSequence.length(); if(length>oldlength) { char newchar = charSequence.charAt(i); if ((newchar < '0' && newchar > '9') && newchar != '.') { if (i != length - 1) row5edit.setText(charSequence.subSequence(0, i).toString() + charSequence.subSequence(i + 1, length).toString()); else row5edit.setText(charSequence.subSequence(0, length - 1)); } } oldlength=length; } @Override public void afterTextChanged(Editable editable) { } }); }}fangdaitext（activity）
package com.example.myapplication_one;public class fangdaitext { public static boolean isNum(String string){ int flag=0; if(string.charAt(0)=='0'&&string.charAt(1)!='.') return false; if(string.charAt(0)=='.') return false; for(int i=0;i<string.length();i++) { if((string.charAt(i)<'0'||string.charAt(i)>'9')&&string.charAt(i)!='.') return false; else if(string.charAt(i)=='.') { flag++; if(flag>1) return false; } } return true; }}fangdai.xml
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="16dp" android:focusableInTouchMode="true" android:focusable="true" tools:context="com.example.myapplication_one.fangdai"> <ScrollView android:layout_width="match_parent" android:layout_height="wrap_content"> <RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content"> <RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/relativeLayout1"> <TextView android:id="@+id/row1label" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="购房总价：" android:layout_centerVertical="true" android:textSize="18sp" /> <EditText android:id="@+id/row1edit" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_centerVertical="true" android:hint="请输入购房总价（单位万）" android:singleLine="true" android:textSize="16dp" android:background="@drawable/edittext_style" android:padding="5dp" android:gravity="right" android:layout_toRightOf="@+id/row1label" android:layout_toLeftOf="@+id/row1endlabel" android:inputType="numberDecimal"/> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="万" android:textSize="18sp" android:layout_marginLeft="10dp" android:layout_centerVertical="true" android:layout_alignParentEnd="true" android:id="@+id/row1endlabel" android:layout_alignParentRight="true" /> </RelativeLayout> <RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/relativeLayout2" android:layout_below="@+id/relativeLayout1" android:layout_marginTop="20dp"> <TextView android:id="@+id/row2label" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="按揭部分：" android:layout_centerVertical="true" android:textSize="18sp" /> <EditText android:id="@+id/row2edit" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_centerVertical="true" android:hint="请输入按揭百分比" android:singleLine="true" android:textSize="16dp" android:background="@drawable/edittext_style" android:padding="5dp" android:gravity="right" android:layout_toRightOf="@+id/row2label" android:layout_toLeftOf="@+id/row2endlabel" android:inputType="numberDecimal"/> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=" %" android:textSize="18sp" android:layout_marginLeft="10dp" android:layout_centerVertical="true" android:layout_alignParentEnd="true" android:id="@+id/row2endlabel" android:layout_alignParentRight="true" /> </RelativeLayout> <Button android:id="@+id/totalcal" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/relativeLayout2" android:layout_marginTop="15dp" android:background="@drawable/btn_style" android:text="计算贷款总额" /> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="其中贷款部分为：***万" android:layout_below="@+id/totalcal" android:layout_marginTop="10dp" android:textSize="16sp" android:id="@+id/showtotal"/> <RelativeLayout android:id="@+id/relativeLayout3" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/showtotal" android:layout_marginTop="10dp"> <TextView android:id="@+id/row3label" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="还款方式：" android:textSize="16sp" android:layout_centerVertical="true"/> <RadioGroup android:id="@+id/radiogroup" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_toRightOf="@+id/row3label" android:orientation="horizontal"> <RadioButton android:id="@+id/btn1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="等额本息" android:checked="true"/> <RadioButton android:id="@+id/btn2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="等额本金" android:layout_marginLeft="10dp"/> </RadioGroup> </RelativeLayout> <RelativeLayout android:id="@+id/relativeLayout4" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/relativeLayout3"> <CheckBox android:id="@+id/check1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="商贷： "/> <EditText android:id="@+id/row4label" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_centerVertical="true" android:hint="请输入商业贷款总额（单位万）" android:singleLine="true" android:textSize="16dp" android:background="@drawable/edittext_style" android:padding="5dp" android:gravity="right" android:layout_toRightOf="@+id/check1" android:layout_toLeftOf="@+id/row4endlabel" android:inputType="numberDecimal"/> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="万" android:textSize="18sp" android:layout_marginLeft="10dp" android:layout_centerVertical="true" android:layout_alignParentEnd="true" android:id="@+id/row4endlabel"/> </RelativeLayout> <RelativeLayout android:id="@+id/relativeLayout5" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/relativeLayout4" android:layout_marginTop="5dp"> <CheckBox android:id="@+id/check2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="公积金："/> <EditText android:id="@+id/row5label" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_centerVertical="true" android:hint="请输入公积金贷款总额（单位万）" android:singleLine="true" android:textSize="16dp" android:background="@drawable/edittext_style" android:padding="5dp" android:gravity="right" android:layout_toRightOf="@+id/check2" android:layout_toLeftOf="@+id/row5endlabel" android:inputType="numberDecimal"/> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="万" android:textSize="18sp" android:layout_marginLeft="10dp" android:layout_centerVertical="true" android:layout_alignParentEnd="true" android:id="@+id/row5endlabel" /> </RelativeLayout> <RelativeLayout android:id="@+id/relativeLayout6" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@id/relativeLayout5" android:layout_marginTop="10dp"> <TextView android:id="@+id/row6label" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="贷款年限：" android:textSize="16sp" android:layout_centerVertical="true"/> <Spinner android:id="@+id/sp1" android:layout_centerVertical="true" android:layout_width="match_parent" android:layout_height="wrap_content" android:spinnerMode="dialog" android:layout_toRightOf="@+id/row6label"> </Spinner> </RelativeLayout> <RelativeLayout android:id="@+id/relativeLayout7" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/relativeLayout6" android:layout_marginTop="10dp"> <TextView android:id="@+id/row7label" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="基准利率：" android:layout_centerVertical="true" android:textSize="16sp"/> <Spinner android:id="@+id/sp2" android:layout_width="match_parent" android:layout_height="wrap_content" android:spinnerMode="dialog" android:layout_centerVertical="true" android:layout_toRightOf="@+id/row7label"> </Spinner> </RelativeLayout> <Button android:id="@+id/detail" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/relativeLayout7" android:layout_marginTop="15dp" android:background="@drawable/btn_style" android:text="计算还款明细"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="还款总额为：***万\n其中利息总额为：***万\n月供（每月还款额）为：***" android:layout_below="@+id/detail" android:layout_marginTop="10dp" android:textSize="16sp" android:id="@+id/alldetail"/> </RelativeLayout> </ScrollView></RelativeLayout>edittext_style.xml
<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:state_focused="true"> <shape> <corners android:radius="5dp"/> <stroke android:width="1dp" android:color="#00DDFF"/> </shape> </item> <item android:state_focused="false"> <shape> <corners android:radius="5dp"/> <stroke android:width="1dp" android:color="#000000"/> </shape> </item></selector>btn_style.xml
<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:state_pressed="true"> <shape> <solid android:color="#808080"/> <corners android:radius="2dp"/> <stroke android:width="1dp" android:color="@color/teal_200"/> </shape> </item> <item android:state_pressed="false"> <shape> <solid android:color="#33E3F3"/> <corners android:radius="2dp"/> <stroke android:width="1dp" android:color="#07AC78"/> </shape> </item></selector>dimens.xml
<resources> <!-- Default screen margins, per the Android Design guidelines. --> <dimen name="activity_horizontal_margin">16dp</dimen> <dimen name="activity_vertical_margin">16dp</dimen></resources>
以上就是“Android如何实现房贷计算器”这篇文章的所有内容，感谢各位的阅读！相信大家阅读完这篇文章都有很大的收获，小编每天都会为大家更新不同的知识，如果还想学习更多的知识，请关注编程网行业资讯频道。
