Question

package com.mg.numbergenerator;

import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import java.util.Random; 
import android.text.InputFilter;
import android.text.Spanned;


public class Main extends Activity {

    EditText min;
    EditText max;

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

      final  Random r = new Random();


    min = (EditText) findViewById (R.id.editText1);
    max = (EditText) findViewById (R.id.editText2);

      final  TextView TextView1 = (TextView) findViewById(R.id.textView1);

     final EditText et1 = (EditText) findViewById(R.id.editText1);
     final EditText et2 = (EditText) findViewById(R.id.editText2);

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

            @SuppressLint("NewApi") @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub

                int number = min + r.nextInt( max - min +1); //error HERE
                TextView1.setText(String.valueOf(number));

            }
        });


    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

Answer 1

min = (EditText) findViewById (R.id.editText1);

min是您正在对其进行数学运算的EdiTtext对象

  int number = min + r.nextInt( max - min +1);

而是从editText获取文本。使用Integer.parseInt(min.getText().toString)。

  try
  {
  int minnumber =  Integer.parseInt(min.getText().toString);
  int maxnumber = Integer.parseInt(max.getText().toString);
  // do operation with minnumber and maxnumber 
  int number = minnumber+ r.nextInt( maxnumber - minnumber +1);
  }
  catch(NumberFormatException e) // thrown if number entered in edittext is not int.
  {
       e.printStacktrace();
  }

http://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html#parseInt(java.lang.String)

Answer 2

你不能只对EditText进行数学运算，它只是一个放置一些值的容器。使用下面的代码从EditText中获取值。

   int min_value= Integer.parseInt(min.getText().toString());
   int max_value= Integer.parseInt(max.getText().toString());

然后使用此值计算数学运算。

int number = min_value +r.nextInt(max_value - min_value + 1 );

为什么我会收到此错误以及如何解决此问题？运算符 - 未定义参数类型android.widget.EditText，android.widget.EditText

2 个答案: