Question

所以这是我到目前为止的代码：

Button calculate = (Button)findViewById(R.id.calculate);
    calculate.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            EditText sun = (EditText)findViewById(R.id.sun1);
            EditText mon = (EditText)findViewById(R.id.mon1);
            EditText tue = (EditText)findViewById(R.id.tue1);
            EditText wed = (EditText)findViewById(R.id.wed1);
            EditText thu = (EditText)findViewById(R.id.thu1);
            EditText fri = (EditText)findViewById(R.id.fri1);
            EditText sat = (EditText)findViewById(R.id.sat1);
            EditText wage = (EditText)findViewById(R.id.wage);

            double sun1 = Double.parseDouble(sun.getText().toString());
            double mon1 = Double.parseDouble(mon.getText().toString());
            double tue1 = Double.parseDouble(tue.getText().toString());
            double wed1 = Double.parseDouble(wed.getText().toString());
            double thu1 = Double.parseDouble(thu.getText().toString());
            double fri1 = Double.parseDouble(fri.getText().toString());
            double sat1 = Double.parseDouble(sat.getText().toString());
            double wage1 = Double.parseDouble(wage.getText().toString());
            TextView hours = (TextView)findViewById(R.id.hours);
            TextView income = (TextView)findViewById(R.id.Income);  
            if(wage.getText().length()==0){
                Toast.makeText(getContext(), "Enter the wage", Toast.LENGTH_SHORT).show();
            }
            else{
            Calculator calc = new Calculator(sun1,mon1,tue1,wed1,thu1,fri1,sat1,wage1);
            hours.setText(calc.hours()+"");
            income.setText(calc.calc()+"");
            }

正如您所看到的，每当用户将任何字段留空时，我都希望显示一个Toast。在这种情况下，我只使用工资对象来显示我失败的地方。我也尝试过wage.getText（）。toString（）。equals（＆＃34;＆＃34;）仍然我的应用程序崩溃了。也许这是吐司课，我错了。在maketoast中使用（this）而不是getContext（）也没有帮助。有什么建议？

Answer 1

您收到了错误消息，因为findViewById(...)并未绑定到正确的this。它应该在onClick监听器之外。

通常，我会做类似以下的事情：

public class MainActivity extends Activity {

private EditText sun;
private EditText mon;
private EditText tue;
private EditText wed;
private EditText thu;
private EditText fri;
private EditText sat;
private EditText wage;

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

    instantiateViews();
}

private void instantiateViews() {

    sun  = (EditText) findViewById(R.id.sun1);
    mon  = (EditText) findViewById(R.id.mon1);
    tue  = (EditText) findViewById(R.id.tue1);
    wed  = (EditText) findViewById(R.id.wed1);
    thu  = (EditText) findViewById(R.id.thu1);
    fri  = (EditText) findViewById(R.id.fri1);
    sat  = (EditText) findViewById(R.id.sat1);
    wage = (EditText) findViewById(R.id.wage);
}

//Write whatever other code you would here
}

此外，我建议您使用TextUtils.isEmpty优先于当前方法检查wage是否为空。

使用toast处理空的EditText

1 个答案: