在 Android 中如何检查无线电组中的单选按钮是否被检查？

我需要设置验证，用户必须填写/选择页面中的所有细节。如果任何字段是空的想要显示 Toast message to fill.现在我需要在 RadioGroup.中为 RadioButton设置验证，我尝试了这个代码，但是没有正常工作。给我正确的建议。谢谢。

// get selected radio button from radioGroup
int selectedId = gender.getCheckedRadioButtonId();
// find the radiobutton by returned id
selectedRadioButton = (RadioButton)findViewById(selectedId);
// do what you want with radioButtonText (save it to database in your case)
radioButtonText = selectedRadioButton.getText().toString();


if(radioButtonText.matches(""))
{
Toast.makeText(getApplicationContext(), "Please select Gender", Toast.LENGTH_SHORT).show();
Log.d("QAOD", "Gender is Null");
}
else
{
Log.d("QAOD", "Gender is Selected");
}
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小开

Use the isChecked() function for every radioButton you have to check.

RadioButton maleRadioButton, femaleRadioButton;


maleRadioButton = (RadioButton) findViewById(R.id.maleRadioButton);
femaleRadioButton = (RadioButton) findViewById(R.id.femaleRadioButton);

Then use the result for your if/else case consideration.

if (maleRadioButton.isChecked() || femaleRadioButton.isChecked()) {
Log.d("QAOD", "Gender is Selected");
} else {
Toast.makeText(getApplicationContext(), "Please select Gender", Toast.LENGTH_SHORT).show();
Log.d("QAOD", "Gender is Null");
}
小开

Try to use the method isChecked();

Like,

selectedRadioButton.isChecked() -> returns boolean.

Refere here for more details on Radio Button

小开
最佳答案

If you want to check on just one RadioButton you can use the isChecked function

if(radioButton.isChecked())
{
// is checked
}
else
{
// not checked
}

and if you have a RadioGroup you can use

if (radioGroup.getCheckedRadioButtonId() == -1)
{
// no radio buttons are checked
}
else
{
// one of the radio buttons is checked
}
小开

All you need to do is use getCheckedRadioButtonId() and isChecked() method,

if(gender.getCheckedRadioButtonId()==-1)
{
Toast.makeText(getApplicationContext(), "Please select Gender", Toast.LENGTH_SHORT).show();
}
else
{
// get selected radio button from radioGroup
int selectedId = gender.getCheckedRadioButtonId();
// find the radiobutton by returned id
selectedRadioButton = (RadioButton)findViewById(selectedId);
Toast.makeText(getApplicationContext(), selectedRadioButton.getText().toString()+" is selected", Toast.LENGTH_SHORT).show();
}

https://developer.android.com/guide/topics/ui/controls/radiobutton.html

小开

I used the id's of my radiobuttons to compare with the id of the checkedRadioButton that I got using mRadioGroup.getCheckedRadioButtonId()

Here is my code:

mRadioButton1=(RadioButton)findViewById(R.id.first);
mRadioButton2=(RadioButton)findViewById(R.id.second);
mRadioButton3=(RadioButton)findViewById(R.id.third);
mRadioButton4=(RadioButton)findViewById(R.id.fourth);


mNextButton=(Button)findViewById(R.id.next_button);


mNextButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int selectedId=mRadioGroup.getCheckedRadioButtonId();


int n=0;
if(selectedId==R.id.first){n=1;}


else if(selectedId==R.id.second){n=2;}


else if(selectedId==R.id.third){n=3;}


else if(selectedId==R.id.fourth){n=4;}
//. . . .
}
小开

try to use this

<RadioGroup
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<RadioButton
android:id="@+id/standard_delivery"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/Standard_delivery"
android:checked="true"
android:layout_marginTop="4dp"
android:layout_marginLeft="15dp"
android:textSize="12dp"
android:onClick="onRadioButtonClicked"
/>


<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/Midnight_delivery"
android:checked="false"
android:layout_marginRight="15dp"
android:layout_marginTop="4dp"
android:textSize="12dp"
android:onClick="onRadioButtonClicked"
android:id="@+id/midnight_delivery"
/>
</RadioGroup>

this is java class

public void onRadioButtonClicked(View view) {
// Is the button now checked?
boolean checked = ((RadioButton) view).isChecked();


// Check which radio button was clicked
switch(view.getId()) {
case R.id.standard_delivery:
if (checked)
Toast.makeText(DishActivity.this," standard delivery",Toast.LENGTH_LONG).show();
break;
case R.id.midnight_delivery:
if (checked)
Toast.makeText(DishActivity.this," midnight delivery",Toast.LENGTH_LONG).show();
break;
}
}
小开

My answer is according to the documentation, which works fine.

1) In xml file include android:onClick="onRadioButtonClicked" as shown below:

<RadioGroup
android:id="@+id/rg1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:gravity="center">
<RadioButton
android:id="@+id/b1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="onCreateOptionsMenu()"
android:onClick="onRadioButtonClicked"
/>
<RadioButton
android:id="@+id/b2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="onCreateMenu()"
android:onClick="onRadioButtonClicked"
/>
</RadioGroup>

2) In Java file implement onRadioButtonClicked method outside onCreate() method as shown below:

public void onRadioButtonClicked(View view) {
// Is the button now checked?
boolean checked = ((RadioButton) view).isChecked();


// Check which radio button was clicked
switch(view.getId()) {
case R.id.b1:
if (checked)
{
Log.e("b1", "b1" );
break;
}
case R.id.b2:
if (checked)
break;
}
}
小开

I used the following and it worked for me. I used a boolean validation function where if any Radio Button in a Radio Group is checked, the validation function returns true and a submission is made. if returned false, no submission is made and a toast to "Select Gender" is shown:

  1. MainActivity.java

    public class MainActivity extends AppCompatActivity {
private RadioGroup genderRadioGroup;


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


//Initialize Radio Group And Submit Button
genderRadioGroup=findViewById(R.id.gender_radiogroup);
AppCompatButton submit = findViewById(R.id.btnSubmit);


//Submit Radio Group using Submit Button
submit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//Check Gender radio Group For Selected Radio Button
if(genderRadioGroup.getCheckedRadioButtonId()==-1){//No Radio Button Is Checked
Toast.makeText(getApplicationContext(), "Please Select Gender", Toast.LENGTH_LONG).show();
}else{//Radio Button Is Checked
RadioButton selectedRadioButton = findViewById(genderRadioGroup.getCheckedRadioButtonId());
gender = selectedRadioButton == null ? "" : selectedRadioButton.getText().toString().trim();
}
//Validate
if (validateInputs()) {
//code to proceed when Radio button is checked
}
}
}
//Validation - No process is initialized if no Radio button is checked
private boolean validateInputs() {
if (genderRadioGroup.getCheckedRadioButtonId()==-1) {
return false;
}
return true;
}
}

  2. In activity_main.xml:

    <LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">


<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/gender"/>


<RadioGroup
android:id="@+id/gender_radiogroup"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">


<RadioButton
android:id="@+id/male"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/male"/>


<RadioButton
android:id="@+id/female"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/female""/>


</RadioGroup>


<android.support.v7.widget.AppCompatButton
android:id="@+id/btnSubmit"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/submit"/>


</LinearLayout>

If no gender radio button is selected, then the code to proceed will not run.

I hope this helps.

小开 
  rgrp.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup radioGroup, int i) {
switch(i) {
case R.id.type_car:
num=1;
Toast.makeText(getApplicationContext()," Car",Toast.LENGTH_LONG).show();
break;
case R.id.type_bike:
num=2;
Toast.makeText(getApplicationContext()," Bike",Toast.LENGTH_LONG).show();
break;
}
}
});
小开 
mRadioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup radioGroup, int i) {
if (mRadioButtonMale.isChecked()) {
text = "male";
} else {
text = "female";
}
}
});

OR

 mRadioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup radioGroup, int i) {
if (mRadioButtonMale.isChecked()) { text = "male"; }
if(mRadioButtonFemale.isChecked()) { text = "female"; }
}
});
小开 
radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup radioGroup, int checkedId) {
checkedId = radioGroup.getCheckedRadioButtonId();


switch (checkedId) {
case R.id.expert_rb:
// do something
break;
case R.id.no_expert_rb:
// do something else
break;
                   

}
}
});

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