我正在制作一个计算器应用程序，其中我想显示一个警告是用户将任何东西除以零.REST一切正常但我用户将任何东西除以零，应该提出警告
package com.example.calculator;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class Calci extends Activity {
TextView t1;
EditText e1, e2;
Button add, sub, mul, div;
Context c = this;
String b, a;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_calci);
e1 = (EditText) findViewById(R.id.EditText01);
e2 = (EditText) findViewById(R.id.EditText02);
add = (Button) findViewById(R.id.add);
sub = (Button) findViewById(R.id.sub);
mul = (Button) findViewById(R.id.mul);
div = (Button) findViewById(R.id.div);
t1 = (TextView) findViewById(R.id.textView1);
div.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
a = e1.getText().toString();
b = e2.getText().toString();
AlertDialog.Builder a1 = new AlertDialog.Builder(c);
try{
if (a.equals("") || b.equals("")) {
// AlertDialog.Builder a1 = new AlertDialog.Builder(c);
// Setting Dialog Title
a1.setTitle("Alert Dialog");
// Setting Dialog Message
a1.setMessage("PLEASE ENTER SOMETHING");
a1.setPositiveButton("yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int button1) {
// if this button is clicked, close
// current activity
dialog.cancel();
}
});
// Showing Alert Message
AlertDialog alertDialog = a1.create();
a1.show();
}
}
catch (ArithmeticException e) {
Log.d("ERROR", "msg");
}
// if (b.equals(0)) {
// a1.setTitle("INVALID");
// a1.setMessage("CAnnot divide by zero");
// a1.setPositiveButton("YES",
// new DialogInterface.OnClickListener() {
// public void onClick(DialogInterface dialog,
// int button1) {
// // if this button is clicked, close
// // current activity
// dialog.cancel();
// }
//
// });
// AlertDialog alertDialog = a1.create();
// a1.show();
Log.d("sadasd", "msg");
int result = Integer.parseInt(a) / Integer.parseInt(b);
t1.setText(Integer.toString(result));
InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(add.getWindowToken(),
InputMethodManager.RESULT_UNCHANGED_SHOWN);
}
});
mul.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
a = e1.getText().toString();
b = e2.getText().toString();
if (a.equals("") || b.equals("")) {
AlertDialog.Builder a1 = new AlertDialog.Builder(c);
// Setting Dialog Title
a1.setTitle("Alert Dialog");
// Setting Dialog Message
a1.setMessage("PLEASE ENTER SOMETHING");
a1.setPositiveButton("yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int button1) {
// if this button is clicked, close
// current activity
dialog.cancel();
}
});
// Showing Alert Message
AlertDialog alertDialog = a1.create();
a1.show();
}
else {
Log.d("sadasd", "msg");
int result = Integer.parseInt(a) * Integer.parseInt(b);
t1.setText(Integer.toString(result));
InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(add.getWindowToken(),
InputMethodManager.RESULT_UNCHANGED_SHOWN);
}
}
});
sub.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
a = e1.getText().toString();
b = e2.getText().toString();
if (a.equals("") || b.equals("")) {
AlertDialog.Builder a1 = new AlertDialog.Builder(c);
// Setting Dialog Title
a1.setTitle("Alert Dialog");
// Setting Dialog Message
a1.setMessage("PLEASE ENTER SOMETHING");
a1.setPositiveButton("yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int button1) {
// if this button is clicked, close
// current activity
dialog.cancel();
}
});
// Showing Alert Message
AlertDialog alertDialog = a1.create();
a1.show();
}
else {
Log.d("sadasd", "msg");
int result = Integer.parseInt(a) - Integer.parseInt(b);
t1.setText(Integer.toString(result));
InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(add.getWindowToken(),
InputMethodManager.RESULT_UNCHANGED_SHOWN);
}
}
});
add.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
a = e1.getText().toString();
b = e2.getText().toString();
if (a.equals("") || b.equals("")) {
AlertDialog.Builder a1 = new AlertDialog.Builder(c);
// Setting Dialog Title
a1.setTitle("Alert Dialog");
// Setting Dialog Message
a1.setMessage("PLEASE ENTER SOMETHING");
a1.setPositiveButton("yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int button1) {
// if this button is clicked, close
// current activity
dialog.cancel();
}
});
// Showing Alert Message
AlertDialog alertDialog = a1.create();
a1.show();
}
else {
Log.d("sadasd", "msg");
int result = Integer.parseInt(a) + Integer.parseInt(b);
t1.setText(Integer.toString(result));
InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(add.getWindowToken(),
InputMethodManager.RESULT_UNCHANGED_SHOWN);
}
}
});
}
}
我正在制作一个计算器应用程序，我想在其中显示警告，用户将任何东西除以零。
答案 0 :(得分：0)
勾选Div按钮onClick（）函数。
String divd = edittext.getText().toString();
if(divd.equals("0")){
Toast.makeText(ActivityName.this, "You are dividing by 0", Toast.LENGTH_LONG).show();
return;
}
答案 1 :(得分：0)
简单，只需添加一个条件
div.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
a = e1.getText().toString();
b = e2.getText().toString();
AlertDialog.Builder a1 = new AlertDialog.Builder(c);
try{
if (a.equals("") || b.equals("") || b.equals("0")) {
........
.........
或者你可以这样做
if (a.equals("") || b.equals("") {
.......
.......
}else if (b.equals("0")){
AlertDialog.Builder a1 = new AlertDialog.Builder(calci.this);
a1.setTitle("INVALID");
a1.setMessage("CAnnot divide by zero");
a1.setPositiveButton("YES",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int button1) {
// if this button is clicked, close
// current activity
dialog.cancel();
}
});
AlertDialog alertDialog = a1.create();
a1.show();
}else{
....
....
}
答案 2 :(得分：0)
a = e1.getText().toString();
b = e2.getText().toString();
AlertDialog.Builder a1 = new AlertDialog.Builder(c);
try{
if b.equals("0")) {
// AlertDialog.Builder a1 = new AlertDialog.Builder(c);
// Setting Dialog Title
a1.setTitle("Alert Dialog");
// Setting Dialog Message
a1.setMessage("You are dividing by 0");
a1.setPositiveButton("OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int button1) {
// if this button is clicked, close
// current activity
dialog.cancel();
}
});
// Showing Alert Message
AlertDialog alertDialog = a1.create();
a1.show();
}
}
catch (ArithmeticException e) {
Log.d("ERROR", "msg");
}
答案 3 :(得分：0)
尝试实现EditText Change Listener
textMessage = (EditText)findViewById(R.id.textMessage);
textMessage.addTextChangedListener(new TextWatcher(){
public void afterTextChanged(Editable s) {
}
public void beforeTextChanged(CharSequence s, int start, int count, int after){}
public void onTextChanged(CharSequence s, int start, int before, int count){
if(s.toString.equal("0")){
Toast.makeText(c, "You are dividing by 0", Toast.LENGTH_LONG).show();
}
}
});