Java 当我没有'；虽然我提到了代码，但我没有给出任何输入
创建的应用程序将查找数字是否为三角形。有关更多详细信息，请参阅 现在，当我在文本视图中单击按钮而不提供任何输入时，应用程序突然关闭。不应该是这样，因为我已经在代码中为空字符串使用了if语句Java 当我没有'；虽然我提到了代码，但我没有给出任何输入,java,android,Java,Android,创建的应用程序将查找数字是否为三角形。有关更多详细信息，请参阅 现在，当我在文本视图中单击按钮而不提供任何输入时，应用程序突然关闭。不应该是这样，因为我已经在代码中为空字符串使用了if语句 package com.example.numbershapes; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View;
package com.example.numbershapes;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
class Number {
int number;
public boolean isTriangular() {
int x = 1;
int triangularNmbr = 1;
while (triangularNmbr < number) {
x++;
triangularNmbr += x;
}
if(triangularNmbr == number) {
return true;
}
else {
return false;
}
}
}
public class MainActivity extends AppCompatActivity {
public void testNumber(View view)
{
EditText usersNumber =
(EditText)findViewById(R.id.usersNumber);
String message = "";
if(usersNumber.getText().toString().isEmpty()){
message = "Please enter a number";
}
Number myNumber = new Number();
myNumber.number =
Integer.parseInt(usersNumber.getText().toString());
//will display on logcat
System.out.println(myNumber.isTriangular());
if(myNumber.isTriangular()){
message = myNumber.number + " is triangular" ;
}
else{
message = myNumber.number + " is not triangular" ;
}
Toast.makeText(getApplicationContext(), message,
Toast.LENGTH_LONG).show();
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
package com.example.numbershapes；
导入android.support.v7.app.AppActivity；
导入android.os.Bundle；
导入android.view.view；
导入android.widget.EditText；
导入android.widget.Toast；
班号{
整数；
公共布尔isTriangular（）{
int x=1；
int triangularNmbr=1；
while（triangularNmbr- 应用程序关闭时的Logcat详细信息
Caused by: java.lang.NumberFormatException: For input string: ""
at java.lang.Integer.parseInt(Integer.java:620)
at java.lang.Integer.parseInt(Integer.java:643)
at stackoverflow57836483.MainActivity.testNumber(MainActivity.java:39)
myNumber.number = Integer.parseInt(usersNumber.getText().toString());
if(usersNumber.getText().toString().isEmpty()){
message = "Please enter a number";
}
public void testNumber(View view)
{
EditText usersNumber = (EditText)findViewById(R.id.usersNumber);
String message = "";
if(usersNumber.getText().toString().isEmpty()){
message = "Please enter a number";
} else { // ELSE STARTS HERE...
Number myNumber = new Number();
myNumber.number = Integer.parseInt(usersNumber.getText().toString());
//will display on logcat
System.out.println(myNumber.isTriangular());
if(myNumber.isTriangular()){
message = myNumber.number + " is triangular" ;
}
else{
message = myNumber.number + " is not triangular" ;
}
} // AND ENDS HERE
Toast.makeText(getApplicationContext(), message, Toast.LENGTH_LONG).show();
}