我创建了一个添加两个数字的应用程序但是当编辑文本为空时按下按钮的应用程序一直停止

Posted 2021-05-03

这是我的代码，但是当我按下按钮而不给数字应用程序整天停止时请告诉我我能为此做些什么代码如下

公共类MainActivity扩展Activity {TextView结果;

EditText editText1, editText2;
Button btnadd;


@Override

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);






             editText1 = (EditText) findViewById(R.id.editText1);
             editText2 = (EditText) findViewById(R.id.editText2);
             btnadd = (Button) findViewById(R.id.btnadd);
             result = (TextView) findViewById(R.id.textviewresult);


             btnadd.setOnClickListener(new View.OnClickListener()




             {
                 @Override
                 public void onClick(View view) {








                     int a = Integer.parseInt(editText1.getText().toString());
                     int b = Integer.parseInt(editText2.getText().toString());

                     int add = a + b;



                     result.setText("Answer: " + String.valueOf(add));


             }
             });

答案

试试这个，也限制编辑文本只允许数字..

`````````````````
int a = 0;
int b = 0;

if(!editText1.getText().toString().trim().equalsIgnoreCase(""))
    a = Integer.parseInt(editText1.getText().toString());
if(!editText2.getText().toString().trim().equalsIgnoreCase(""))
    b = Integer.parseInt(editText2.getText().toString());

int add = a + b;
result.setText("Answer: " + String.valueOf(add));
```````````````````````

另一答案

问题是Integer.parseInt无法解析空字符串

所以我查了一下

Check if EditText is empty.

我修改了你的代码

public class MainActivity extends AppCompatActivity {

TextView result;
EditText editText1, editText2;
Button btnadd;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    editText1 = (EditText) findViewById(R.id.editText1);
    editText2 = (EditText) findViewById(R.id.editText2);
    btnadd = (Button) findViewById(R.id.btnadd);
    result = (TextView) findViewById(R.id.textviewresult);


    btnadd.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            int a;
            int b;
            if (editText1.getText().toString().matches("")) {

                a=0;
            } else{
             a = Integer.parseInt(editText1.getText().toString());
            }

            if (editText2.getText().toString().matches("")) {
                b = 0;
            }else {
                b = Integer.parseInt(editText2.getText().toString());
            }

            int add = a + b;


            result.setText("Answer: " + String.valueOf(add));


        }

    });
}

}

另一答案

private void intiView() {
    edt1 = findViewById(R.id.edt1);
    edt2 = findViewById(R.id.edt2);
    btnSum = findViewById(R.id.btnSum);
    txtAns=findViewById(R.id.txtAns);
    btnSum.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (!edt1.getText().toString().isEmpty() && !edt2.getText().toString().isEmpty()) {
                sum = Integer.parseInt(edt1.getText().toString()) + Integer.parseInt(edt2.getText().toString());
                Toast.makeText(Main2Activity.this, "Sum of two nos: " + sum, Toast.LENGTH_LONG).show();
                txtAns.setText(""+sum);
            } else if (edt1.getText().toString().isEmpty()) {
                edt1.setError("Please enter no1 ");
            } else if (edt2.getText().toString().isEmpty()) {
                edt2.setError("Please enter no2 ");

            }
        }
    });
}