如何验证 EditText。应用程序在提交时崩溃，EditText 中没有任何值
How can I validate EditText. App is getting crashed on submit without any value in EditText
我正在尝试验证 EditText 以进行强制检查。所以我用 hasText() 函数创建了 Validation.java 。即使在使用这个之后，当没有值在 EditText 中传递而不是显示警告时，我的应用程序也会崩溃。
在下面附上我的代码。
Homescreen.class
package com.test.tax;
import android.content.Intent;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextWatcher;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import android.text.Editable;
import java.text.DecimalFormat;
import static com.test.tax.R.id.editText;
import static java.lang.Math.round;
public class HomeScreen extends AppCompatActivity {
public static String Buy_Price = "a";
public static String Sell_Price = "b";
public static String QUANTITY = "c";
public static String BROKERAGE = "d";
public static String ActualProfitLoss_String = "e";
public static String TurnOver_String = "f";
public static String STT_String = "g";
public static String ServiceTax_String = "h";
public static String TotalCharge_String = "i";
public static String x = "j";
private static String Strin ;
EditText editText;
EditText editText2;
EditText editText3;
EditText editText4;
Button btnSubmit;
boolean doubleBackToExitPressedOnce = false;
@Override
public void onBackPressed() {
if (doubleBackToExitPressedOnce) {
super.onBackPressed();
return;
}
this.doubleBackToExitPressedOnce = true;
Toast.makeText(this, "Please click BACK again to exit", Toast.LENGTH_SHORT).show();
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
doubleBackToExitPressedOnce=false;
}
}, 2000);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home_screen);
}
public void calculateProfit(View view) {
Intent intent = new Intent(this, displayProfit.class);
Bundle extras =new Bundle();
editText=(EditText) findViewById(R.id.editText);
editText.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
Validation.hasText(editText);
}
public void beforeTextChanged(CharSequence s, int start, int count, int after){}
public void onTextChanged(CharSequence s, int start, int before, int count){}
});
editText4=(EditText) findViewById(R.id.editText4);
editText4.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
Validation.hasText(editText4);
}
public void beforeTextChanged(CharSequence s, int start, int count, int after){}
public void onTextChanged(CharSequence s, int start, int before, int count){}
});
editText2=(EditText) findViewById(R.id.editText2);
editText2.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
Validation.hasText(editText2);
}
public void beforeTextChanged(CharSequence s, int start, int count, int after){}
public void onTextChanged(CharSequence s, int start, int before, int count){}
});
editText3=(EditText) findViewById(R.id.editText3);
editText3.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
Validation.hasText(editText3);
}
public void beforeTextChanged(CharSequence s, int start, int count, int after){}
public void onTextChanged(CharSequence s, int start, int before, int count){}
});
btnSubmit = (Button) findViewById(R.id.button);
btnSubmit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
/*
Validation class will check the error and display the error on respective fields
but it won't resist the form submission, so we need to check again before submit
*/
}
});
Log.d(Strin, "editText ::::");
String buyPriceString = editText3.getText().toString();
Float BuyPrice = Float.parseFloat(buyPriceString);
String quantityString = editText2.getText().toString();
Float Quantity = Float.parseFloat(quantityString);
String sellPriceString = editText4.getText().toString();
Float SellPrice = Float.parseFloat(sellPriceString);
String brokerageString = editText.getText().toString();
Float Brokerage = Float.parseFloat(brokerageString);
Log.d(Strin, "SellPrice ::::"+SellPrice);
Log.d(Strin, "BuyPrice ::::"+BuyPrice);
Log.d(Strin, "Quantity ::::"+Quantity);
Log.d(Strin, "Brokerage ::::"+Brokerage);
double TurnOver=(BuyPrice*Quantity)+(SellPrice*Quantity);
double TurnOver1=roundTwoDecimals(TurnOver);
Log.d(Strin, "TurnOver ::::"+TurnOver);
double Sell1 =SellPrice-(SellPrice*(Brokerage/100));
Log.d(Strin, "Sell1 ::::"+Sell1);
double Buy1 = BuyPrice+(BuyPrice*(Brokerage/100));
Log.d(Strin, "Buy1 ::::"+Buy1);
double TotalBrokerage = ((Sell1*Brokerage/100)+(Buy1*Brokerage/100));
Log.d(Strin, "TotalBrokerage ::::"+TotalBrokerage);
double STT = (Quantity*(SellPrice-(SellPrice*(Brokerage/100))))*(.025/100);
double STT1 = roundTwoDecimals(STT);
Log.d(Strin, "STT ::::"+STT);
double TrnxChrge = TurnOver*(0.00275/100);
Log.d(Strin, "TrnxChrge ::::"+TrnxChrge);
double ServiceTax = (TotalBrokerage+STT)*(.15);
double ServiceTax1 = roundTwoDecimals(ServiceTax);
Log.d(Strin, "ServiceTax ::::"+ServiceTax);
double SEBICharge = (TurnOver*(.0002/100));
Log.d(Strin, "SEBICharge ::::"+SEBICharge);
double TotalCharge = ServiceTax+TrnxChrge+SEBICharge+STT;
double TotalCharge1 = roundTwoDecimals(TotalCharge);
Log.d(Strin, "TotalCharge ::::"+TotalCharge);
double NetProfit = (Sell1-Buy1)*Quantity;
Log.d(Strin, "NetProfit ::::"+NetProfit);
double ActualProfitLoss = (NetProfit -TotalCharge);
double ActualProfitLoss1 = roundTwoDecimals(ActualProfitLoss);
String ActualProfitLossString=Double.toString(ActualProfitLoss1);
String TurnOverString=Double.toString(TurnOver1);
String STTString=Double.toString(STT1);
String ServiceTaxString=Double.toString(ServiceTax1);
String TotalChargeString=Double.toString(TotalCharge1);
Log.d(Strin, "Pavi ::::"+ActualProfitLossString);
extras.putString(ActualProfitLoss_String,ActualProfitLossString);
extras.putString(TurnOver_String,TurnOverString);
extras.putString(STT_String,STTString);
extras.putString(ServiceTax_String,ServiceTaxString);
extras.putString(TotalCharge_String,TotalChargeString);
extras.putString(Buy_Price,buyPriceString);
extras.putString(Sell_Price,sellPriceString);
extras.putString(BROKERAGE,brokerageString);
extras.putString(QUANTITY,quantityString);
Log.d(Strin, "buyPrice ::::"+ActualProfitLoss);
// intent.putExtra(Sell_Price,sellPriceString);
// intent.putExtra(QUANTITY,quantity);
intent.putExtras(extras);
startActivity(intent);
}
private double roundTwoDecimals(double d) {
DecimalFormat twoDForm = new DecimalFormat("#.##");
return Double.valueOf(twoDForm.format(d));
}
}
Validation.java
public class Validation {
public static boolean hasText(EditText editText) {
String text = editText.getText().toString().trim();
editText.setError(null);
// length 0 means there is no text
if (text.length() == 0) {
editText.setError("REQUIRED_Data");
return false;
}
return true;
}
}
调试日志：
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.test.tax, PID: 3290
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
at android.view.View.performClick(View.java:5610)
at android.view.View$PerformClick.run(View.java:22265)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:5610)
at android.view.View$PerformClick.run(View.java:22265)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Caused by: java.lang.NumberFormatException: empty String
at java.lang.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1071)
at java.lang.Float.parseFloat(Float.java:459)
at com.test.tax.HomeScreen.calculateProfit(HomeScreen.java:121)
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:5610)
at android.view.View$PerformClick.run(View.java:22265)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Disconnected from the target VM, address: 'localhost:8601', transport: 'socket'
您的问题显示在
Caused by: java.lang.NumberFormatException: empty String
at java.lang.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1071)
at java.lang.Float.parseFloat(Float.java:459)
at com.test.tax.HomeScreen.calculateProfit(HomeScreen.java:121)
at java.lang.reflect.Method.invoke(Native Method)
您在 calculateProfit 中的一个 parseFloat 方法正在抛出这个。这是由于有一个空字符串。
在解析为浮点数之前，将所有空字符串转换为零如：
buyPriceString = buyPriceString.length() > 0 ? buyPriceString : "0";
这一行有错误（任何类似的行都会抛出同样的错误）
Float BuyPrice = Float.parseFloat(buyPriceString);
在 Validation.hasText() 的帮助下使用它之前，您必须始终检查 EditText 中是否输入了值。
例如，像 So，这些行：
String buyPriceString = editText3.getText().toString();
Float BuyPrice = Float.parseFloat(buyPriceString);
应该是这样
if(Validation.hasText(editText3)){
String buyPriceString = editText3.getText().toString();
Float BuyPrice = Float.parseFloat(buyPriceString);
}
并且记得对所有其他 edittexts
此外，您可能希望将 Validation.hasText() 的工作方式更改为以下方式：
if (text.equals("") ) {
editText.setError("REQUIRED_Data");
return false;
}
我正在尝试验证 EditText 以进行强制检查。所以我用 hasText() 函数创建了 Validation.java 。即使在使用这个之后，当没有值在 EditText 中传递而不是显示警告时，我的应用程序也会崩溃。 在下面附上我的代码。
Homescreen.class
package com.test.tax;
import android.content.Intent;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextWatcher;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import android.text.Editable;
import java.text.DecimalFormat;
import static com.test.tax.R.id.editText;
import static java.lang.Math.round;
public class HomeScreen extends AppCompatActivity {
public static String Buy_Price = "a";
public static String Sell_Price = "b";
public static String QUANTITY = "c";
public static String BROKERAGE = "d";
public static String ActualProfitLoss_String = "e";
public static String TurnOver_String = "f";
public static String STT_String = "g";
public static String ServiceTax_String = "h";
public static String TotalCharge_String = "i";
public static String x = "j";
private static String Strin ;
EditText editText;
EditText editText2;
EditText editText3;
EditText editText4;
Button btnSubmit;
boolean doubleBackToExitPressedOnce = false;
@Override
public void onBackPressed() {
if (doubleBackToExitPressedOnce) {
super.onBackPressed();
return;
}
this.doubleBackToExitPressedOnce = true;
Toast.makeText(this, "Please click BACK again to exit", Toast.LENGTH_SHORT).show();
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
doubleBackToExitPressedOnce=false;
}
}, 2000);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home_screen);
}
public void calculateProfit(View view) {
Intent intent = new Intent(this, displayProfit.class);
Bundle extras =new Bundle();
editText=(EditText) findViewById(R.id.editText);
editText.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
Validation.hasText(editText);
}
public void beforeTextChanged(CharSequence s, int start, int count, int after){}
public void onTextChanged(CharSequence s, int start, int before, int count){}
});
editText4=(EditText) findViewById(R.id.editText4);
editText4.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
Validation.hasText(editText4);
}
public void beforeTextChanged(CharSequence s, int start, int count, int after){}
public void onTextChanged(CharSequence s, int start, int before, int count){}
});
editText2=(EditText) findViewById(R.id.editText2);
editText2.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
Validation.hasText(editText2);
}
public void beforeTextChanged(CharSequence s, int start, int count, int after){}
public void onTextChanged(CharSequence s, int start, int before, int count){}
});
editText3=(EditText) findViewById(R.id.editText3);
editText3.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
Validation.hasText(editText3);
}
public void beforeTextChanged(CharSequence s, int start, int count, int after){}
public void onTextChanged(CharSequence s, int start, int before, int count){}
});
btnSubmit = (Button) findViewById(R.id.button);
btnSubmit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
/*
Validation class will check the error and display the error on respective fields
but it won't resist the form submission, so we need to check again before submit
*/
}
});
Log.d(Strin, "editText ::::");
String buyPriceString = editText3.getText().toString();
Float BuyPrice = Float.parseFloat(buyPriceString);
String quantityString = editText2.getText().toString();
Float Quantity = Float.parseFloat(quantityString);
String sellPriceString = editText4.getText().toString();
Float SellPrice = Float.parseFloat(sellPriceString);
String brokerageString = editText.getText().toString();
Float Brokerage = Float.parseFloat(brokerageString);
Log.d(Strin, "SellPrice ::::"+SellPrice);
Log.d(Strin, "BuyPrice ::::"+BuyPrice);
Log.d(Strin, "Quantity ::::"+Quantity);
Log.d(Strin, "Brokerage ::::"+Brokerage);
double TurnOver=(BuyPrice*Quantity)+(SellPrice*Quantity);
double TurnOver1=roundTwoDecimals(TurnOver);
Log.d(Strin, "TurnOver ::::"+TurnOver);
double Sell1 =SellPrice-(SellPrice*(Brokerage/100));
Log.d(Strin, "Sell1 ::::"+Sell1);
double Buy1 = BuyPrice+(BuyPrice*(Brokerage/100));
Log.d(Strin, "Buy1 ::::"+Buy1);
double TotalBrokerage = ((Sell1*Brokerage/100)+(Buy1*Brokerage/100));
Log.d(Strin, "TotalBrokerage ::::"+TotalBrokerage);
double STT = (Quantity*(SellPrice-(SellPrice*(Brokerage/100))))*(.025/100);
double STT1 = roundTwoDecimals(STT);
Log.d(Strin, "STT ::::"+STT);
double TrnxChrge = TurnOver*(0.00275/100);
Log.d(Strin, "TrnxChrge ::::"+TrnxChrge);
double ServiceTax = (TotalBrokerage+STT)*(.15);
double ServiceTax1 = roundTwoDecimals(ServiceTax);
Log.d(Strin, "ServiceTax ::::"+ServiceTax);
double SEBICharge = (TurnOver*(.0002/100));
Log.d(Strin, "SEBICharge ::::"+SEBICharge);
double TotalCharge = ServiceTax+TrnxChrge+SEBICharge+STT;
double TotalCharge1 = roundTwoDecimals(TotalCharge);
Log.d(Strin, "TotalCharge ::::"+TotalCharge);
double NetProfit = (Sell1-Buy1)*Quantity;
Log.d(Strin, "NetProfit ::::"+NetProfit);
double ActualProfitLoss = (NetProfit -TotalCharge);
double ActualProfitLoss1 = roundTwoDecimals(ActualProfitLoss);
String ActualProfitLossString=Double.toString(ActualProfitLoss1);
String TurnOverString=Double.toString(TurnOver1);
String STTString=Double.toString(STT1);
String ServiceTaxString=Double.toString(ServiceTax1);
String TotalChargeString=Double.toString(TotalCharge1);
Log.d(Strin, "Pavi ::::"+ActualProfitLossString);
extras.putString(ActualProfitLoss_String,ActualProfitLossString);
extras.putString(TurnOver_String,TurnOverString);
extras.putString(STT_String,STTString);
extras.putString(ServiceTax_String,ServiceTaxString);
extras.putString(TotalCharge_String,TotalChargeString);
extras.putString(Buy_Price,buyPriceString);
extras.putString(Sell_Price,sellPriceString);
extras.putString(BROKERAGE,brokerageString);
extras.putString(QUANTITY,quantityString);
Log.d(Strin, "buyPrice ::::"+ActualProfitLoss);
// intent.putExtra(Sell_Price,sellPriceString);
// intent.putExtra(QUANTITY,quantity);
intent.putExtras(extras);
startActivity(intent);
}
private double roundTwoDecimals(double d) {
DecimalFormat twoDForm = new DecimalFormat("#.##");
return Double.valueOf(twoDForm.format(d));
}
}
Validation.java
public class Validation {
public static boolean hasText(EditText editText) {
String text = editText.getText().toString().trim();
editText.setError(null);
// length 0 means there is no text
if (text.length() == 0) {
editText.setError("REQUIRED_Data");
return false;
}
return true;
}
}
调试日志：
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.test.tax, PID: 3290
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
at android.view.View.performClick(View.java:5610)
at android.view.View$PerformClick.run(View.java:22265)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:5610)
at android.view.View$PerformClick.run(View.java:22265)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Caused by: java.lang.NumberFormatException: empty String
at java.lang.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1071)
at java.lang.Float.parseFloat(Float.java:459)
at com.test.tax.HomeScreen.calculateProfit(HomeScreen.java:121)
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:5610)
at android.view.View$PerformClick.run(View.java:22265)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Disconnected from the target VM, address: 'localhost:8601', transport: 'socket'
您的问题显示在
Caused by: java.lang.NumberFormatException: empty String
at java.lang.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1071)
at java.lang.Float.parseFloat(Float.java:459)
at com.test.tax.HomeScreen.calculateProfit(HomeScreen.java:121)
at java.lang.reflect.Method.invoke(Native Method)
您在 calculateProfit 中的一个 parseFloat 方法正在抛出这个。这是由于有一个空字符串。
在解析为浮点数之前，将所有空字符串转换为零如：
buyPriceString = buyPriceString.length() > 0 ? buyPriceString : "0";
这一行有错误（任何类似的行都会抛出同样的错误）
Float BuyPrice = Float.parseFloat(buyPriceString);
在 Validation.hasText() 的帮助下使用它之前，您必须始终检查 EditText 中是否输入了值。
例如，像 So，这些行：
String buyPriceString = editText3.getText().toString();
Float BuyPrice = Float.parseFloat(buyPriceString);
应该是这样
if(Validation.hasText(editText3)){
String buyPriceString = editText3.getText().toString();
Float BuyPrice = Float.parseFloat(buyPriceString);
}
并且记得对所有其他 edittexts
此外，您可能希望将 Validation.hasText() 的工作方式更改为以下方式：
if (text.equals("") ) {
editText.setError("REQUIRED_Data");
return false;
}