Question

我必须编辑文本，如果我点击添加按钮而不在edittext中输入任何内容，我会得到fc。

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.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;;

    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);
        a = e1.getText().toString();
        b = e2.getText().toString();

    }

    public void doSomething(View v) {
        AlertDialog.Builder a1 = new AlertDialog.Builder(c);

        if (v.getId() == R.id.add) {
            if (a==null & b==null) {
Log.e("hash","asdasd");
                // 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 {

            int result = Integer.parseInt(a) + Integer.parseInt(b);
            t1.setText(Integer.toString(result));
        }
    }

}

Answer 1

请删除“public void doSomething（View v）”的内容，

在下面的活动的oncreate（）上使用onclicklistener按钮，

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

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
 if( e1.getText().toString().equals("") ||  e2.getText().toString().equals(""))
{
          new AlertDialog.Builder(MainActivity.this)
            .setTitle("INPUT ALERT")
            .setIcon(R.drawable.galleryalart)
            .setMessage("PLEASE ENTER THE INPUT??")

            .setPositiveButton("OK", new OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // TODO Auto-generated method stub  


            }
        }).create().show();

        }
  else {

        int result = Integer.parseInt( e2.getText().toString()) + Integer.parseInt( e2.getText().toString());
        t1.setText(result+"");
    }   

        }
    });

如果用户未输入所需信息，如何显示警报

1 个答案: