Question

我是android的新手，我正在尝试使用radiogroups的示例程序。我在放射组下面宣布了2个单选按钮。我想要选择哪个单选按钮 RadioGroup中。希望在Anonymous类new onClickListener的if和elseif条件中使用它。

我试图声明一个整数变量radio_selected并获取radgrp.getCheckedRadioButtonId（）的返回值 radio_selected = radgrp.getCheckedRadioButtonId（）;并在if和else if条件中使用常量进行比较，

if（radio_selected == R.id.rdb1＆amp;＆amp;（edit1.getText（）。toString（）。equals（“admin”））＆amp;＆amp;（edit2.getText（）。toString（）。等于（ “管理员”）））

我试图打印radio_selected的值。它打印我-1意味着空选。但是radgrp.getCheckedRadioButtonId（）;返回一个整数值。但是上面的程序编译并正常工作，但我想知道为什么我不能使用radio_selected常量来进行比较？

.java文件

package android.button;


import android.app.Activity;

import android.os.Bundle;

import android.text.Editable;

import android.text.method.KeyListener;

import android.util.Log;

import android.view.KeyEvent;

import android.view.View;

import android.view.View.OnClickListener;

import android.view.View.OnKeyListener;

import android.widget.Button;

import android.widget.EditText;

import android.widget.RadioGroup;

import android.widget.Toast;

import android.widget.RadioGroup.OnCheckedChangeListener;


public class Android_eg2 extends Activity {


/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

final int radio_selected;


final EditText edit1 = (EditText)findViewById(R.id.txt1);

final EditText edit2 = (EditText)findViewById(R.id.txt2);

edit2.setOnKeyListener(new OnKeyListener() {


public boolean onKey(View v, int keyCode, KeyEvent event) {

// TODO Auto-generated method stub

if(edit2.getText().toString().length()>5){

Toast.makeText(getApplicationContext(), "EXCEEDED the MAX LIMIT", Toast.LENGTH_LONG).show();

}

return false;

}

});

final RadioGroup radgrp = (RadioGroup)findViewById(R.id.rad);

//radio_selected = radgrp.getCheckedRadioButtonId();

Button bt = (Button)findViewById(R.id.button);

bt.setOnClickListener(new OnClickListener() {


public void onClick(View v) {

//System.out. println(radgrp.getCheckedRadioButtonId());

//System.out.println(radio_selected);

// TODO Auto-generated method stub

if(R.id.button == v.getId()){

if( radgrp.getCheckedRadioButtonId() == R.id.rdb1 && (edit1.getText().toString().equals("admin")) && (edit2.getText().toString().equals("admin"))){

Toast.makeText(getApplicationContext(),"LOGIN SUCCESS FOR ADMIN",Toast.LENGTH_LONG).show();

Log.v("TAG","In admin");

}

else if(radgrp.getCheckedRadioButtonId() == R.id.rdb2 && (edit1.getText().toString().equalsIgnoreCase("user")) && (edit2.getText().toString().equalsIgnoreCase("user"))){

Toast.makeText(getApplicationContext(),"LOGIN SUCCESS FOR USER",Toast.LENGTH_LONG).show();

Log.v("TAG","In user");

}

else{

Toast.makeText(getApplicationContext(),"INVALID ENTRY",Toast.LENGTH_LONG).show();

Log.v("TAG","Invalid");

}

}

}

});


radgrp.setOnCheckedChangeListener(new OnCheckedChangeListener() {


public void onCheckedChanged(RadioGroup group, int checkedId) {

// TODO Auto-generated method stub

switch(checkedId){

case R.id.rdb1:

//Toast.makeText(getApplicationContext(),"ADMIN",Toast.LENGTH_LONG).show();

case R.id.rdb2:

//Toast.makeText(getApplicationContext(),"USER",Toast.LENGTH_LONG).show();

}

}

});

}

}

main.xml文件

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>

<TextView 

android:layout_width="wrap_content" 

android:layout_height="wrap_content" 

android:text="Welcome to wipro"

/>


<LinearLayout

android:orientation="vertical"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

>


<RadioGroup

android:id="@+id/rad"

android:layout_width="wrap_content" 

android:layout_height="wrap_content" 

android:orientation="horizontal"

>

<RadioButton

android:id="@+id/rdb1"

android:layout_width="wrap_content" 

android:layout_height="wrap_content"

android:text = "Admin"

>

</RadioButton>

<RadioButton

android:id="@+id/rdb2"

android:layout_width="wrap_content" 

android:layout_height="wrap_content"

android:text = "User"

>

</RadioButton>

</RadioGroup>


<LinearLayout

android:orientation="horizontal"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

>




<TextView 

android:id="@+id/lbl1"

android:layout_width="100dp"

android:layout_height="wrap_content"

android:text="USER NAME"

android:textSize="6pt"

android:textColor = "#00aa00"

>


</TextView>


<EditText

android:id="@+id/txt1"

android:layout_width="100dp"

android:layout_height="wrap_content"

android:text=""

android:textSize="6pt"

android:textColor = "#aa0000"

>

</EditText>


</LinearLayout>


<LinearLayout

android:orientation="horizontal"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

>

<TextView

android:id="@+id/lbl2"

android:layout_width="100dp"

android:layout_height="wrap_content"

android:text="PASSWORD"

android:textSize="6pt"

android:textColor="#00aa00"

android:layout_weight="1"


>


</TextView>


<EditText

android:id="@+id/txt2"

android:layout_width="100dp"

android:layout_height="wrap_content"

android:text=""

android:textSize="6pt"

android:textColor = "#aa0000"

android:password = "true"

>

</EditText>


</LinearLayout>


</LinearLayout>


<LinearLayout

android:orientation="horizontal"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

>

<Button

android:id="@+id/button"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="SUBMIT"

>

</Button>


</LinearLayout>


</LinearLayout>

R.java文件

/* AUTO-GENERATED FILE. DO NOT MODIFY.

*

* This class was automatically generated by the

* aapt tool from the resource data it found. It

* should not be modified by hand.

*/


package android.button;


public final class R {

public static final class attr {

}

public static final class drawable {

public static final int icon=0x7f020000;

}

public static final class id {

public static final int button=0x7f050007;

public static final int lbl1=0x7f050003;

public static final int lbl2=0x7f050005;

public static final int rad=0x7f050000;

public static final int rdb1=0x7f050001;

public static final int rdb2=0x7f050002;

public static final int txt1=0x7f050004;

public static final int txt2=0x7f050006;

}

public static final class layout {

public static final int main=0x7f030000;

}

public static final class string {

public static final int app_name=0x7f040001;

public static final int hello=0x7f040000;

}

}

Answer 1

  boolean rad1,rad2=false;

 radio1.setOnCheckedChangeListener(new OnCheckedChangeListener() {

        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            // TODO Auto-generated method stub
            if(radio1.isChecked())
            {
                rad1=true;
            }

        }
    });
radio2.setOnCheckedChangeListener(new OnCheckedChangeListener() {

        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            // TODO Auto-generated method stub
            ifradio2.isChecked())
            {
                rad2=true;
            }

        }
    });

Answer 2

嘿安格斯我觉得你几乎是对的。您的radio_selected变量打印该值的原因是因为您正在尝试获取在创建活动时选择了哪个单选按钮且没有选定的单选按钮，因此其值将为-1。

除此之外，我建议您在活动类中实现OnCheckedChangeListener，这将允许您覆盖onCheckedChanged方法以捕获单选按钮的选择。在您的情况下，您将radio_selected声明为最终变量，这是一个错误！最终意味着一旦定义了该变量，它的值就不能改变，所以即使它有效，它也会第一次工作而不是再次工作。因此，通过这些建议，您的活动可能如下所示：

//all of the imports 

public class TestActivity extends Activity implements OnCheckedChangeListener{

private int radio_selected;//now radio_selected is a class variable
/** Called when the activity is first created. */

@Override
public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    final EditText edit1 = (EditText)findViewById(R.id.txt1);
    final EditText edit2 = (EditText)findViewById(R.id.txt2);
    edit2.setOnKeyListener(new OnKeyListener() {
        public boolean onKey(View v, int keyCode, KeyEvent event) 
        {
        // TODO Auto-generated method stub
            if(edit2.getText().toString().length()>5)
            {
                Toast.makeText(getApplicationContext(), "EXCEEDED the MAX LIMIT", Toast.LENGTH_LONG).show();
            }
        return false;
        }
    });

    final RadioGroup radgrp = (RadioGroup)findViewById(R.id.rad);
    Button bt = (Button)findViewById(R.id.button);
    bt.setOnClickListener(new OnClickListener() 
    {
        public void onClick(View v) 
        {
            System.out. println(radgrp.getCheckedRadioButtonId());
            System.out.println(radio_selected);
            // TODO Auto-generated method stub
            if(R.id.button == v.getId())
            {
                if( radgrp.getCheckedRadioButtonId() == R.id.rdb1 && (edit1.getText().toString().equals("admin")) && (edit2.getText().toString().equals("admin")))
                {
                    Toast.makeText(getApplicationContext(),"LOGIN SUCCESS FOR ADMIN",Toast.LENGTH_LONG).show();
                    Log.v("TAG","In admin");
                }
                else if(radgrp.getCheckedRadioButtonId() == R.id.rdb2 &&   (edit1.getText().toString().equalsIgnoreCase("user")) && (edit2.getText().toString().equalsIgnoreCase("user")))
                {
                    Toast.makeText(getApplicationContext(),"LOGIN SUCCESS FOR USER",Toast.LENGTH_LONG).show();
                    Log.v("TAG","In user");
                }
                else{
                    Toast.makeText(getApplicationContext(),"INVALID ENTRY",Toast.LENGTH_LONG).show();
                    Log.v("TAG","Invalid");
                }
            }
        }
    });
    radgrp.setOnCheckedChangeListener(this); //you set this activity as the listener for the events on the radio group...
}

@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
    // TODO Auto-generated method stub
    switch(checkedId){

    case R.id.rdb1:
        radio_selected = R.id.rdb1;
        Toast.makeText(getApplicationContext(),"ADMIN",Toast.LENGTH_LONG).show();

    case R.id.rdb2:
        radio_selected = R.id.rdb2;
        Toast.makeText(getApplicationContext(),"USER",Toast.LENGTH_LONG).show();
    }
    }
}

请注意，每当选择一个单选按钮时，我都会设置radio_selected的值，这样一旦按下提交按钮，它就会被更新。我希望我已经足够清楚，代码仍然可以改进，但这是另一个答案;）干杯！

Answer 3

   RadioGroup radioGroup ;
   radioGroup  = (RadioGroup)findViewById(R.id.radioGroup);
   radioGroup.setOnCheckedChangeListener(new OnCheckedChangeListener() {


  public void onCheckedChanged(RadioGroup group, int checkedId) {
  switch(checkedId){
    case R.id.radio1:
   Toast.makeText(getApplicationContext(),"RadioButton1selected",Toast.LENGTH_LONG.show();
  case R.id.radio2:
  Toast.makeText(getApplicationContext(),"RadioButton2selected",Toast.LENGTH_LONG).show();}

选择Radiogroup中的单选按钮

.java文件

main.xml文件

R.java文件

3 个答案: