java.lang.ClassCastException:android.widget.TextView不能转换为android.widget.EditText [英] java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.EditText
问题描述
我收到以下错误:
java.lang.ClassCastException:android.widget.TextView无法施放 到android.widget.EditText在 com.example.bmicalculator.MainActivity.initializeApp(MainActivity.java.32)
主要活动:
公共类MainActivity延伸活动{
私人的EditText heightIn;
私人的EditText加权的;
私人按钮CalculateButton;
私人双人体重= 0;
私人双高= 0;
私人TextView的BmiResult;
@覆盖
保护无效的onCreate(包savedInstanceState){
super.onCreate(savedInstanceState);
的setContentView(R.layout.activity_main);
initializeApp();
}
私人无效initializeApp(){
heightIn =(EditText上)findViewById(R.id.HeightInput1);
加权的=(的EditText)findViewById(R.id.WeightInput1);
CalculateButton =(按钮)findViewById(R.id.CalculateButton);
BmiResult =(TextView中)findViewById(R.id.BmiResult);
}
公共无效calculateBMI(视图v){
重量= Double.parseDouble(weightIn.getText()的toString());
身高= Double.parseDouble(heightIn.getText()的toString());
双BMI =(体重/(身高×高));
字符串结果=的String.Format(%2F,BMI);
Log.d(MyActivity,结果);
BmiResult.setText(结果,TextView.BufferType.NORMAL);
}
}
XML文件:
< LinearLayout中的xmlns:工具=http://schemas.android.com/tools
的xmlns:机器人=http://schemas.android.com/apk/res/android
机器人:ID =@ + ID / LinearLayout2
机器人:layout_width =FILL_PARENT
机器人:layout_height =FILL_PARENT
机器人:方向=垂直
工具:上下文=$ {relativePackage} $ {activityClass}。>
<的TextView
机器人:ID =@ + ID / HeightInput1
机器人:layout_width =WRAP_CONTENT
机器人:layout_height =WRAP_CONTENT
机器人:文本=@字符串/ HeightInput
机器人:textAppearance =机器人:ATTR / textAppearanceMedium/>
<的EditText
机器人:ID =@ + ID / editText1
机器人:layout_width =match_parent
机器人:layout_height =WRAP_CONTENT
机器人:EMS =10
机器人:提示=@字符串/ InchesHint
机器人:inputType =numberDecimal>
<不是requestFocus />
< /的EditText>
<的TextView
机器人:ID =@ + ID / WeightInput1
机器人:layout_width =WRAP_CONTENT
机器人:layout_height =WRAP_CONTENT
机器人:文本=@字符串/ WeightInput
机器人:textAppearance =机器人:ATTR / textAppearanceMedium/>
<的EditText
机器人:ID =@ + ID / editText2
机器人:layout_width =match_parent
机器人:layout_height =WRAP_CONTENT
机器人:EMS =10
机器人:提示=@字符串/ PoundsHint
机器人:inputType =numberDecimal/>
<按钮
机器人:ID =@ + ID / CalculateButton
机器人:layout_width =WRAP_CONTENT
机器人:layout_height =WRAP_CONTENT
机器人:的onClick =calculateBMI
机器人:文本=@字符串/ CalculateButton/>
<的TextView
机器人:ID =@ + ID / BmiResult
机器人:layout_width =100dp
机器人:layout_height =0dp
机器人:layout_weight =0.00
机器人:文本=@字符串/ BmiResult/>
您 heightIn
不是的EditText
和你再试图强制转换为的EditText
让你有错误
java.lang.ClassCastException:android.widget.TextView不能 转换为android.widget.EditText在 com.example.bmicalculator.MainActivity.initializeApp(MainActivity.java.32)
这样做的,
heightIn =(TextView中)findViewById(R.id.HeightInput1);
加权的=(的TextView)findViewById(R.id.WeightInput1);
I'm getting the following Error:
java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.EditText at com.example.bmicalculator.MainActivity.initializeApp(MainActivity.java.32)
Main Activity:
public class MainActivity extends Activity {
private EditText heightIn;
private EditText weightIn;
private Button CalculateButton;
private double weight =0;
private double height =0;
private TextView BmiResult;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initializeApp();
}
private void initializeApp() {
heightIn = (EditText) findViewById (R.id.HeightInput1);
weightIn = (EditText) findViewById (R.id.WeightInput1);
CalculateButton = (Button) findViewById (R.id.CalculateButton);
BmiResult = (TextView) findViewById (R.id.BmiResult);
}
public void calculateBMI(View v) {
weight = Double.parseDouble(weightIn.getText().toString());
height = Double.parseDouble(heightIn.getText().toString());
double bmi = (weight / (height * height));
String result = String.format("%.2f", bmi);
Log.d("MyActivity", result);
BmiResult.setText(result, TextView.BufferType.NORMAL);
}
}
XML File:
<LinearLayout xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/LinearLayout2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
tools:context="${relativePackage}.${activityClass}" >
<TextView
android:id="@+id/HeightInput1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/HeightInput"
android:textAppearance="?android:attr/textAppearanceMedium" />
<EditText
android:id="@+id/editText1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="@string/InchesHint"
android:inputType="numberDecimal" >
<requestFocus />
</EditText>
<TextView
android:id="@+id/WeightInput1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/WeightInput"
android:textAppearance="?android:attr/textAppearanceMedium" />
<EditText
android:id="@+id/editText2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:hint="@string/PoundsHint"
android:inputType="numberDecimal" />
<Button
android:id="@+id/CalculateButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="calculateBMI"
android:text="@string/CalculateButton" />
<TextView
android:id="@+id/BmiResult"
android:layout_width="100dp"
android:layout_height="0dp"
android:layout_weight="0.00"
android:text="@string/BmiResult" />
Your heightIn
is not EditText
and you're trying to cast it as EditText
so you got Error
java.lang.ClassCastException: android.widget.TextView cannot be cast to android.widget.EditText at com.example.bmicalculator.MainActivity.initializeApp(MainActivity.java.32)
so do as,
heightIn = (TextView) findViewById (R.id.HeightInput1);
weightIn = (TextView) findViewById (R.id.WeightInput1);
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