检查 Java 中的 RadioButtons 是否未被选中

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英文:

Checking if RadioButtons are not checked in java

问题

我正在学习 Android,在 Java 中制作一个类似图片中所示的简单计算器。我的计算器

尝试运行应用时,两个单选按钮都没有被选中,因此当我按下“计算”按钮时,应用程序会关闭。

我尝试进行一个判断,如果两个按钮都没有被选中,应用程序会显示一个 Toast,但是应用程序无论如何都会关闭。

这是判断的代码(其中 btnSumar 和 btnRestar 是 RadioButtons):

if (!btnSumar.isChecked() && !btnRestar.isChecked()) {
    Toast.makeText(MainActivity.this, "Please, select one option", Toast.LENGTH_SHORT).show();
}

这在我看来是合理的,但它不起作用。

谢谢您的帮助!

以下是 logcat 日志:

2020-09-06 18:51:48.814 10245-10245/com.triopsstudio.seccion01 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.triopsstudio.seccion01, PID: 10245
java.lang.IllegalStateException: Could not execute method for android:onClick
    at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:414)
    at android.view.View.performClick(View.java:7448)
    at android.view.View.performClickInternal(View.java:7425)
    at android.view.View.access$3600(View.java:810)
    at android.view.View$PerformClick.run(View.java:28305)
    at android.os.Handler.handleCallback(Handler.java:938)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:223)
    at android.app.ActivityThread.main(ActivityThread.java:7656)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
 Caused by: java.lang.reflect.InvocationTargetException
    at java.lang.reflect.Method.invoke(Native Method)
    at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:409)
    at android.view.View.performClick(View.java:7448)
    at android.view.View.performClickInternal(View.java:7425)
    at android.view.View.access$3600(View.java:810)
    at android.view.View$PerformClick.run(View.java:28305)
    at android.os.Handler.handleCallback(Handler.java:938)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:223)
    at android.app.ActivityThread.main(ActivityThread.java:7656)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
 Caused by: java.lang.NumberFormatException: For input string: ""
    at java.lang.Integer.parseInt(Integer.java:627)
    at java.lang.Integer.parseInt(Integer.java:650)
    at com.triopsstudio.seccion01.MainActivity.Calcular(MainActivity.java:53)
英文:

I'm learning android making a simple calculator in Java like the one in the image. my calculator

When I try the app, neither of the Radio Buttons are checked, so when I press the 'calculate' button the app shuts down.

I tried making a comprobation and if neither of the buttons are checked the app shows a Toast but the app shuts down anyway.

This is the comprobation code (where btnSumar and btnRestar are the RadioButtons):

if(!btnSumar.isChecked() && !btnRestar.isChecked()) {

       Toast.makeText(MainActivity.this, "Please, select one option", Toast.LENGTH_SHORT).show();
   }

It seems logic to me, but it doesn't work.

Thanks for helping!

this is logcat

2020-09-06 18:51:48.814 10245-10245/com.triopsstudio.seccion01 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.triopsstudio.seccion01, PID: 10245
java.lang.IllegalStateException: Could not execute method for android:onClick
    at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:414)
    at android.view.View.performClick(View.java:7448)
    at android.view.View.performClickInternal(View.java:7425)
    at android.view.View.access$3600(View.java:810)
    at android.view.View$PerformClick.run(View.java:28305)
    at android.os.Handler.handleCallback(Handler.java:938)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:223)
    at android.app.ActivityThread.main(ActivityThread.java:7656)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
 Caused by: java.lang.reflect.InvocationTargetException
    at java.lang.reflect.Method.invoke(Native Method)
    at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:409)
    at android.view.View.performClick(View.java:7448) 
    at android.view.View.performClickInternal(View.java:7425) 
    at android.view.View.access$3600(View.java:810) 
    at android.view.View$PerformClick.run(View.java:28305) 
    at android.os.Handler.handleCallback(Handler.java:938) 
    at android.os.Handler.dispatchMessage(Handler.java:99) 
    at android.os.Looper.loop(Looper.java:223) 
    at android.app.ActivityThread.main(ActivityThread.java:7656) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947) 
 Caused by: java.lang.NumberFormatException: For input string: ""
    at java.lang.Integer.parseInt(Integer.java:627)
    at java.lang.Integer.parseInt(Integer.java:650)
    at com.triopsstudio.seccion01.MainActivity.Calcular(MainActivity.java:53)

答案1

得分: 0

可以通过默认选中一个单选按钮,并获取其在 RadioGroup 中的 ID。

示例:

<RadioGroup
        android:id="@+id/radioSex"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <RadioButton
            android:id="@+id/radioMale"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/radio_male"
            android:checked="true" />

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

</RadioGroup>

MainActivity:

//顶层声明..
private RadioGroup radioSexGroup;
private RadioButton radioSexButton;

`onCreate(Bundle savedInstanceState)`

radioSexGroup = (RadioGroup) findViewById(R.id.radioSex);
  // 从 radioGroup 获取选中的单选按钮
int selectedId = radioSexGroup.getCheckedRadioButtonId();

	// 根据返回的 ID 查找 radiobutton
radioSexButton = (RadioButton) findViewById(selectedId); // 这将得到选中的按钮的 ID
英文:

You can make one of radiobutton checked by default and it's id from radioGroup

ex:

&lt;RadioGroup
        android:id=&quot;@+id/radioSex&quot;
        android:layout_width=&quot;wrap_content&quot;
        android:layout_height=&quot;wrap_content&quot; &gt;

        &lt;RadioButton
            android:id=&quot;@+id/radioMale&quot;
            android:layout_width=&quot;wrap_content&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:text=&quot;@string/radio_male&quot;
            android:checked=&quot;true&quot; /&gt;

        &lt;RadioButton
            android:id=&quot;@+id/radioFemale&quot;
            android:layout_width=&quot;wrap_content&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:text=&quot;@string/radio_female&quot; /&gt;

    &lt;/RadioGroup&gt;

MainActivity:

//top level declaration..
private RadioGroup radioSexGroup;
private RadioButton radioSexButton;

Inside onCreate(Bundle savedInstanceState)

radioSexGroup = (RadioGroup) findViewById(R.id.radioSex);
  // get selected radio button from radioGroup
	int selectedId = radioSexGroup.getCheckedRadioButtonId();

		// find the radiobutton by returned id
  radioSexButton = (RadioButton) findViewById(selectedId);//this will have selected button id

答案2

得分: 0

使用isChecked()函数来检查每个单选按钮。

RadioButton maleRadioButton, femaleRadioButton;

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

然后根据代码情况使用结果来考虑检查单选按钮。

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");
}
英文:

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 code case consideration to check radiobutton.

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

答案3

得分: 0

根据您的堆栈跟踪,您遇到了NumberFormatException,因为您尚未输入任何内容。您尝试从空字符串中解析数字。Integer.parseInt("") 导致异常(MainActivity类的第53行)。

英文:

According to your stacktrace you have a NumberFormatException because you have no input yet. You try to parse number from empty string. Integer.parseInt("") leads to Exception ( lines 53 MainActivity class)

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  • 本文由 发表于 2020年9月7日 01:08:20
  • 转载请务必保留本文链接:https://go.coder-hub.com/63766794.html
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