我正在尝试创建一个程序,它将输入2个不同的数字,并具有按钮功能总和,平均值,产品并清除值....
截至目前,我已经完成了总和和产品,但是当我测试我的程序时,它会强制关闭。请帮助我..
MyFragmentMain.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/design"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.coverttoinches.MainActivity$PlaceholderFragment" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="24dp"
android:layout_marginTop="30dp"
android:text="@string/i"
android:textAppearance="?android:attr/textAppearanceMedium" />
<EditText
android:id="@+id/txtfirstnum"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/textView2"
android:layout_alignLeft="@+id/btnAdd"
android:ems="10"
android:hint="Enter First Number"
android:inputType="number" >
<requestFocus />
</EditText>
<TextView
android:id="@+id/TextView01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/TextView02"
android:layout_below="@+id/txtsecondnum"
android:layout_marginTop="29dp"
android:text="ANSWER"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="@+id/TextView02"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView2"
android:layout_below="@+id/textView1"
android:layout_marginTop="25dp"
android:text="@string/number2"
android:textAppearance="?android:attr/textAppearanceMedium" />
<Button
android:id="@+id/btnAdd"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/txtanswer"
android:layout_centerHorizontal="true"
android:layout_marginTop="14dp"
android:onClick="onClick"
android:text="Addition" />
<Button
android:id="@+id/btnprod"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/btnAdd"
android:layout_alignBottom="@+id/btnAdd"
android:layout_alignLeft="@+id/TextView01"
android:onClick="onClick"
android:text="Product" />
<Button
android:id="@+id/btnave"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/btnAdd"
android:layout_alignBottom="@+id/btnAdd"
android:layout_alignRight="@+id/txtanswer"
android:onClick="onClick"
android:text="Average" />
<Button
android:id="@+id/btnclear"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/btnAdd"
android:layout_alignRight="@+id/btnAdd"
android:layout_below="@+id/btnAdd"
android:layout_marginTop="14dp"
android:onClick="onClick"
android:text="Clear" />
<EditText
android:id="@+id/txtsecondnum"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/TextView02"
android:layout_alignBottom="@+id/TextView02"
android:layout_alignLeft="@+id/txtfirstnum"
android:layout_alignParentRight="true"
android:ems="10"
android:hint="Enter Second Number"
android:inputType="number" />
<EditText
android:id="@+id/txtanswer"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/TextView01"
android:layout_alignLeft="@+id/txtsecondnum"
android:ems="10"
android:inputType="number" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/textView1"
android:layout_alignBottom="@+id/textView1"
android:layout_marginRight="15dp"
android:layout_toLeftOf="@+id/txtfirstnum"
android:text="@string/number1"
android:textAppearance="?android:attr/textAppearanceMedium" />
</RelativeLayout>
我的MainActivity.java
package com.example.activity2;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends ActionBarActivity {
EditText editFirst,editSecond,editAnswer;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_main);
editFirst = (EditText) findViewById(R.id.txtfirstnum);
editSecond = (EditText) findViewById(R.id. txtsecondnum);
editAnswer = (EditText) findViewById(R.id.txtanswer);
Button btnAdd = (Button) findViewById(R.id.btnAdd);
Button btnprod = (Button) findViewById(R.id.btnprod);
Button btnClear = (Button) findViewById(R.id.btnclear);
Button btnAvez = (Button) findViewById(R.id.btnave);
btnAdd.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
double first= 0;
double second=0;
double sagot= 0;
double sagot2 =0;
first=Double.parseDouble(editFirst.getText().toString());
second=Double.parseDouble(editSecond.getText().toString());
sagot= first + second;
editAnswer.setText(String.valueOf(sagot));
}
});
btnprod.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
double first= 0;
double second=0;
double sagot= 0;
double sagot2 =0;
first=Double.parseDouble(editFirst.getText().toString());
second=Double.parseDouble(editSecond.getText().toString());
sagot2= first * second;
editAnswer.setText(String.valueOf(sagot2));
}
});
btnClear.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
editFirst.setText(String.valueOf(""));
editSecond.setText(String.valueOf(""));
editAnswer.setText(String.valueOf(""));
}
});
btnAvez.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
double first= 0;
double second=0;
double sagot= 0;
double sagot2 =0;
first=Double.parseDouble(editFirst.getText().toString());
second=Double.parseDouble(editSecond.getText().toString());
sagot= first + second;
sagot2=sagot/2;
editAnswer.setText(String.valueOf(sagot2));
}
});
logcat的:
04-15 07:02:45.887: E/AndroidRuntime(3223): FATAL EXCEPTION: main
04-15 07:02:45.887: E/AndroidRuntime(3223): Process: com.example.activity2, PID: 3223
04-15 07:02:45.887: E/AndroidRuntime(3223): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.activity2/com.example.activity2.MainActivity}: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
04-15 07:02:45.887: E/AndroidRuntime(3223): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
04-15 07:02:45.887: E/AndroidRuntime(3223): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
04-15 07:02:45.887: E/AndroidRuntime(3223): at android.app.ActivityThread.access$800(ActivityThread.java:135)
04-15 07:02:45.887: E/AndroidRuntime(3223): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
04-15 07:02:45.887: E/AndroidRuntime(3223): at android.os.Handler.dispatchMessage(Handler.java:102)
04-15 07:02:45.887: E/AndroidRuntime(3223): at android.os.Looper.loop(Looper.java:136)
04-15 07:02:45.887: E/AndroidRuntime(3223): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-15 07:02:45.887: E/AndroidRuntime(3223): at java.lang.reflect.Method.invokeNative(Native Method)
04-15 07:02:45.887: E/AndroidRuntime(3223): at java.lang.reflect.Method.invoke(Method.java:515)
04-15 07:02:45.887: E/AndroidRuntime(3223): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-15 07:02:45.887: E/AndroidRuntime(3223): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-15 07:02:45.887: E/AndroidRuntime(3223): at dalvik.system.NativeStart.main(Native Method)
04-15 07:02:45.887: E/AndroidRuntime(3223): Caused by: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
04-15 07:02:45.887: E/AndroidRuntime(3223): at com.example.activity2.MainActivity.onCreate(MainActivity.java:17)
04-15 07:02:45.887: E/AndroidRuntime(3223): at android.app.Activity.performCreate(Activity.java:5231)
04-15 07:02:45.887: E/AndroidRuntime(3223): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
04-15 07:02:45.887: E/AndroidRuntime(3223): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
04-15 07:02:45.887: E/AndroidRuntime(3223): ... 11 more
04-15 07:07:46.287: I/Process(3223): Sending signal. PID: 3223 SIG: 9
04-15 07:09:39.007: D/AndroidRuntime(3269): Shutting down VM
04-15 07:09:39.007: W/dalvikvm(3269): threadid=1: thread exiting with uncaught exception (group=0xb2aadba8)
04-15 07:09:39.077: D/dalvikvm(3269): GC_FOR_ALLOC freed 88K, 6% free 3099K/3276K, paused 44ms, total 46ms
04-15 07:09:39.077: E/AndroidRuntime(3269): FATAL EXCEPTION: main
04-15 07:09:39.077: E/AndroidRuntime(3269): Process: com.example.activity2, PID: 3269
04-15 07:09:39.077: E/AndroidRuntime(3269): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.activity2/com.example.activity2.MainActivity}: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
04-15 07:09:39.077: E/AndroidRuntime(3269): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
04-15 07:09:39.077: E/AndroidRuntime(3269): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
04-15 07:09:39.077: E/AndroidRuntime(3269): at android.app.ActivityThread.access$800(ActivityThread.java:135)
04-15 07:09:39.077: E/AndroidRuntime(3269): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
04-15 07:09:39.077: E/AndroidRuntime(3269): at android.os.Handler.dispatchMessage(Handler.java:102)
04-15 07:09:39.077: E/AndroidRuntime(3269): at android.os.Looper.loop(Looper.java:136)
04-15 07:09:39.077: E/AndroidRuntime(3269): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-15 07:09:39.077: E/AndroidRuntime(3269): at java.lang.reflect.Method.invokeNative(Native Method)
04-15 07:09:39.077: E/AndroidRuntime(3269): at java.lang.reflect.Method.invoke(Method.java:515)
04-15 07:09:39.077: E/AndroidRuntime(3269): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-15 07:09:39.077: E/AndroidRuntime(3269): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-15 07:09:39.077: E/AndroidRuntime(3269): at dalvik.system.NativeStart.main(Native Method)
04-15 07:09:39.077: E/AndroidRuntime(3269): Caused by: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
04-15 07:09:39.077: E/AndroidRuntime(3269): at com.example.activity2.MainActivity.onCreate(MainActivity.java:17)
04-15 07:09:39.077: E/AndroidRuntime(3269): at android.app.Activity.performCreate(Activity.java:5231)
04-15 07:09:39.077: E/AndroidRuntime(3269): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
04-15 07:09:39.077: E/AndroidRuntime(3269): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
04-15 07:09:39.077: E/AndroidRuntime(3269): ... 11 more
04-15 07:13:11.577: D/AndroidRuntime(3308): Shutting down VM
04-15 07:13:11.577: W/dalvikvm(3308): threadid=1: thread exiting with uncaught exception (group=0xb2aadba8)
04-15 07:13:11.637: D/dalvikvm(3308): GC_FOR_ALLOC freed 89K, 6% free 3098K/3276K, paused 35ms, total 38ms
04-15 07:13:11.647: E/AndroidRuntime(3308): FATAL EXCEPTION: main
04-15 07:13:11.647: E/AndroidRuntime(3308): Process: com.example.activity2, PID: 3308
04-15 07:13:11.647: E/AndroidRuntime(3308): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.activity2/com.example.activity2.MainActivity}: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
04-15 07:13:11.647: E/AndroidRuntime(3308): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
04-15 07:13:11.647: E/AndroidRuntime(3308): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
04-15 07:13:11.647: E/AndroidRuntime(3308): at android.app.ActivityThread.access$800(ActivityThread.java:135)
04-15 07:13:11.647: E/AndroidRuntime(3308): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
04-15 07:13:11.647: E/AndroidRuntime(3308): at android.os.Handler.dispatchMessage(Handler.java:102)
04-15 07:13:11.647: E/AndroidRuntime(3308): at android.os.Looper.loop(Looper.java:136)
04-15 07:13:11.647: E/AndroidRuntime(3308): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-15 07:13:11.647: E/AndroidRuntime(3308): at java.lang.reflect.Method.invokeNative(Native Method)
04-15 07:13:11.647: E/AndroidRuntime(3308): at java.lang.reflect.Method.invoke(Method.java:515)
04-15 07:13:11.647: E/AndroidRuntime(3308): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-15 07:13:11.647: E/AndroidRuntime(3308): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-15 07:13:11.647: E/AndroidRuntime(3308): at dalvik.system.NativeStart.main(Native Method)
04-15 07:13:11.647: E/AndroidRuntime(3308): Caused by: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
04-15 07:13:11.647: E/AndroidRuntime(3308): at com.example.activity2.MainActivity.onCreate(MainActivity.java:17)
04-15 07:13:11.647: E/AndroidRuntime(3308): at android.app.Activity.performCreate(Activity.java:5231)
04-15 07:13:11.647: E/AndroidRuntime(3308): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
04-15 07:13:11.647: E/AndroidRuntime(3308): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
04-15 07:13:11.647: E/AndroidRuntime(3308): ... 11 more
04-15 07:13:14.457: I/Process(3308): Sending signal. PID: 3308 SIG: 9
04-15 07:24:33.137: D/AndroidRuntime(3348): Shutting down VM
04-15 07:24:33.137: W/dalvikvm(3348): threadid=1: thread exiting with uncaught exception (group=0xb2aadba8)
04-15 07:24:33.197: D/dalvikvm(3348): GC_FOR_ALLOC freed 90K, 6% free 3097K/3276K, paused 44ms, total 46ms
04-15 07:24:33.197: E/AndroidRuntime(3348): FATAL EXCEPTION: main
04-15 07:24:33.197: E/AndroidRuntime(3348): Process: com.example.activity2, PID: 3348
04-15 07:24:33.197: E/AndroidRuntime(3348): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.activity2/com.example.activity2.MainActivity}: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
04-15 07:24:33.197: E/AndroidRuntime(3348): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
04-15 07:24:33.197: E/AndroidRuntime(3348): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
04-15 07:24:33.197: E/AndroidRuntime(3348): at android.app.ActivityThread.access$800(ActivityThread.java:135)
04-15 07:24:33.197: E/AndroidRuntime(3348): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
04-15 07:24:33.197: E/AndroidRuntime(3348): at android.os.Handler.dispatchMessage(Handler.java:102)
04-15 07:24:33.197: E/AndroidRuntime(3348): at android.os.Looper.loop(Looper.java:136)
04-15 07:24:33.197: E/AndroidRuntime(3348): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-15 07:24:33.197: E/AndroidRuntime(3348): at java.lang.reflect.Method.invokeNative(Native Method)
04-15 07:24:33.197: E/AndroidRuntime(3348): at java.lang.reflect.Method.invoke(Method.java:515)
04-15 07:24:33.197: E/AndroidRuntime(3348): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-15 07:24:33.197: E/AndroidRuntime(3348): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-15 07:24:33.197: E/AndroidRuntime(3348): at dalvik.system.NativeStart.main(Native Method)
04-15 07:24:33.197: E/AndroidRuntime(3348): Caused by: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
04-15 07:24:33.197: E/AndroidRuntime(3348): at com.example.activity2.MainActivity.onCreate(MainActivity.java:17)
04-15 07:24:33.197: E/AndroidRuntime(3348): at android.app.Activity.performCreate(Activity.java:5231)
04-15 07:24:33.197: E/AndroidRuntime(3348): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
04-15 07:24:33.197: E/AndroidRuntime(3348): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
04-15 07:24:33.197: E/AndroidRuntime(3348): ... 11 more
04-15 07:26:02.637: D/AndroidRuntime(3388): Shutting down VM
04-15 07:26:02.637: W/dalvikvm(3388): threadid=1: thread exiting with uncaught exception (group=0xb2aadba8)
04-15 07:26:02.697: D/dalvikvm(3388): GC_FOR_ALLOC freed 93K, 6% free 3094K/3276K, paused 52ms, total 54ms
04-15 07:26:02.707: E/AndroidRuntime(3388): FATAL EXCEPTION: main
04-15 07:26:02.707: E/AndroidRuntime(3388): Process: com.example.activity2, PID: 3388
04-15 07:26:02.707: E/AndroidRuntime(3388): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.activity2/com.example.activity2.MainActivity}: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
04-15 07:26:02.707: E/AndroidRuntime(3388): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
04-15 07:26:02.707: E/AndroidRuntime(3388): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
04-15 07:26:02.707: E/AndroidRuntime(3388): at android.app.ActivityThread.access$800(ActivityThread.java:135)
04-15 07:26:02.707: E/AndroidRuntime(3388): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
04-15 07:26:02.707: E/AndroidRuntime(3388): at android.os.Handler.dispatchMessage(Handler.java:102)
04-15 07:26:02.707: E/AndroidRuntime(3388): at android.os.Looper.loop(Looper.java:136)
04-15 07:26:02.707: E/AndroidRuntime(3388): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-15 07:26:02.707: E/AndroidRuntime(3388): at java.lang.reflect.Method.invokeNative(Native Method)
04-15 07:26:02.707: E/AndroidRuntime(3388): at java.lang.reflect.Method.invoke(Method.java:515)
04-15 07:26:02.707: E/AndroidRuntime(3388): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-15 07:26:02.707: E/AndroidRuntime(3388): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-15 07:26:02.707: E/AndroidRuntime(3388): at dalvik.system.NativeStart.main(Native Method)
04-15 07:26:02.707: E/AndroidRuntime(3388): Caused by: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
04-15 07:26:02.707: E/AndroidRuntime(3388): at com.example.activity2.MainActivity.onCreate(MainActivity.java:17)
04-15 07:26:02.707: E/AndroidRuntime(3388): at android.app.Activity.performCreate(Activity.java:5231)
04-15 07:26:02.707: E/AndroidRuntime(3388): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
04-15 07:26:02.707: E/AndroidRuntime(3388): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
04-15 07:26:02.707: E/AndroidRuntime(3388): ... 11 more
04-15 07:26:04.977: I/Process(3388): Sending signal. PID: 3388 SIG: 9
04-15 07:31:52.157: D/AndroidRuntime(3437): Shutting down VM
04-15 07:31:52.157: W/dalvikvm(3437): threadid=1: thread exiting with uncaught exception (group=0xb2aadba8)
04-15 07:31:52.207: D/dalvikvm(3437): GC_FOR_ALLOC freed 96K, 6% free 3092K/3276K, paused 39ms, total 40ms
04-15 07:31:52.207: E/AndroidRuntime(3437): FATAL EXCEPTION: main
04-15 07:31:52.207: E/AndroidRuntime(3437): Process: com.example.activity2, PID: 3437
04-15 07:31:52.207: E/AndroidRuntime(3437): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.activity2/com.example.activity2.MainActivity}: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
04-15 07:31:52.207: E/AndroidRuntime(3437): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
04-15 07:31:52.207: E/AndroidRuntime(3437): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
04-15 07:31:52.207: E/AndroidRuntime(3437): at android.app.ActivityThread.access$800(ActivityThread.java:135)
04-15 07:31:52.207: E/AndroidRuntime(3437): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
04-15 07:31:52.207: E/AndroidRuntime(3437): at android.os.Handler.dispatchMessage(Handler.java:102)
04-15 07:31:52.207: E/AndroidRuntime(3437): at android.os.Looper.loop(Looper.java:136)
04-15 07:31:52.207: E/AndroidRuntime(3437): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-15 07:31:52.207: E/AndroidRuntime(3437): at java.lang.reflect.Method.invokeNative(Native Method)
04-15 07:31:52.207: E/AndroidRuntime(3437): at java.lang.reflect.Method.invoke(Method.java:515)
04-15 07:31:52.207: E/AndroidRuntime(3437): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-15 07:31:52.207: E/AndroidRuntime(3437): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-15 07:31:52.207: E/AndroidRuntime(3437): at dalvik.system.NativeStart.main(Native Method)
04-15 07:31:52.207: E/AndroidRuntime(3437): Caused by: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
04-15 07:31:52.207: E/AndroidRuntime(3437): at com.example.activity2.MainActivity.onCreate(MainActivity.java:17)
04-15 07:31:52.207: E/AndroidRuntime(3437): at android.app.Activity.performCreate(Activity.java:5231)
04-15 07:31:52.207: E/AndroidRuntime(3437): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
04-15 07:31:52.207: E/AndroidRuntime(3437): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
04-15 07:31:52.207: E/AndroidRuntime(3437): ... 11 more
04-15 07:31:56.397: I/Process(3437): Sending signal. PID: 3437 SIG: 9
答案 0 :(得分:1)
你的RelativeLayout和你的按钮&#34;平均&#34;具有相同的ID android:id =&#34; @ + id / btnave&#34;
更改其中一个并清理项目。
答案 1 :(得分:-1)
试试这个..
同时从android:onClick="onClick"
和btnAdd
btnprod``Button
public class MainActivity extends ActionBarActivity {
EditText editFirst,editSecond,editAnswer;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_main);
editFirst = (EditText) findViewById(R.id.txtfirstnum);
editSecond = (EditText) findViewById(R.id. txtsecondnum);
editAnswer = (EditText) findViewById(R.id.txtanswer);
Button btnAdd = (Button) findViewById(R.id.btnAdd);
Button btnprod = (Button) findViewById(R.id.btnprod);
btnAdd.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
double first= 0;
double second=0;
double sagot= 0;
double sagot2 =0;
first=Double.parseDouble(editFirst.getText().toString());
second=Double.parseDouble(editSecond.getText().toString());
sagot= first + second;
editAnswer.setText(String.valueOf(sagot));
}
});
btnprod.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
double first= 0;
double second=0;
double sagot= 0;
double sagot2 =0;
first=Double.parseDouble(editFirst.getText().toString());
second=Double.parseDouble(editSecond.getText().toString());
sagot2= first * second;
editAnswer.setText(String.valueOf(sagot2));
}
});
}
修改强>
从主android:id="@+id/btnave"
RelativeLayout