Question

我无法打开我的申请。据我所知，它是第一次出现我创建一个新类（现在它被删除）。即使我删除//referencje下面的所有内容以及与它们相关的部分布局，也会出现错误。该类的名称已经过编辑，但之后就已经开始工作了。

09-12 18:56:25.512: E/AndroidRuntime(616): FATAL EXCEPTION: main
09-12 18:56:25.512: E/AndroidRuntime(616): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.test2/com.example.test2.activity_main}: java.lang.ClassNotFoundException: com.example.test2.activity_main
09-12 18:56:25.512: E/AndroidRuntime(616):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1983)
09-12 18:56:25.512: E/AndroidRuntime(616):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
09-12 18:56:25.512: E/AndroidRuntime(616):  at android.app.ActivityThread.access$600(ActivityThread.java:130)
09-12 18:56:25.512: E/AndroidRuntime(616):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
09-12 18:56:25.512: E/AndroidRuntime(616):  at android.os.Handler.dispatchMessage(Handler.java:99)
09-12 18:56:25.512: E/AndroidRuntime(616):  at android.os.Looper.loop(Looper.java:137)
09-12 18:56:25.512: E/AndroidRuntime(616):  at android.app.ActivityThread.main(ActivityThread.java:4745)
09-12 18:56:25.512: E/AndroidRuntime(616):  at java.lang.reflect.Method.invokeNative(Native Method)
09-12 18:56:25.512: E/AndroidRuntime(616):  at java.lang.reflect.Method.invoke(Method.java:511)
09-12 18:56:25.512: E/AndroidRuntime(616):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
09-12 18:56:25.512: E/AndroidRuntime(616):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
09-12 18:56:25.512: E/AndroidRuntime(616):  at dalvik.system.NativeStart.main(Native Method)
09-12 18:56:25.512: E/AndroidRuntime(616): Caused by: java.lang.ClassNotFoundException: com.example.test2.activity_main
09-12 18:56:25.512: E/AndroidRuntime(616):  at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
09-12 18:56:25.512: E/AndroidRuntime(616):  at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
09-12 18:56:25.512: E/AndroidRuntime(616):  at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
09-12 18:56:25.512: E/AndroidRuntime(616):  at android.app.Instrumentation.newActivity(Instrumentation.java:1053)
09-12 18:56:25.512: E/AndroidRuntime(616):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1974)
09-12 18:56:25.512: E/AndroidRuntime(616):  ... 11 more

Funkcja.java

package com.example.test2;


import android.app.ActionBar;
import android.app.Activity;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class Funkcja extends Activity {
    TextView wynik;
    Button przelicz;
    EditText wspXa, wspXb, wspYa, wspYb;
    double n1; 

    public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

        //referencje
        wynik = (TextView) findViewById(R.id.wynik);
        przelicz = (Button) findViewById(R.id.przelicz);
        wspXa = (EditText) findViewById(R.id.wspXa);
        wspYa = (EditText) findViewById(R.id.wspYa);
        wspXb = (EditText) findViewById(R.id.wspXb);
        wspYb = (EditText) findViewById(R.id.wspYb);
        //Hiding status bar     
       if (Build.VERSION.SDK_INT < 16) {
           getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                   WindowManager.LayoutParams.FLAG_FULLSCREEN);
       }
       View decorView = getWindow().getDecorView();
    int uiOptions = View.SYSTEM_UI_FLAG_FULLSCREEN;
    decorView.setSystemUiVisibility(uiOptions);
    ActionBar actionBar = getActionBar();
    actionBar.hide();
    przelicz.setOnClickListener(new OnClickListener(){

        public void onClick(View v) {
        try{
            if(wspXa!=null){
            double n1 = Double.parseDouble(wspXa.getText().toString());
            if (n1!=0){
                String total = Double.toString(n1);
                wynik.setText(total);
            }
            }
        }
        catch(Exception e){
        Toast.makeText(getBaseContext(), "Bledne dane", Toast.LENGTH_LONG).show();
        }
        }
    }); 
    } 
}

清单

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.test2"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="16"
        android:targetSdkVersion="16" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".activity_main"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

布局：

<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: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="activity_main" >

    <Spinner
        android:id="@+id/spinner1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/literaA"
        android:layout_alignLeft="@+id/literaA" />

  <EditText
        android:id="@+id/wspYa"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/literaB"
        android:layout_toRightOf="@+id/przelicz"
        android:ems="10"
        android:inputType="numberDecimal"
        android:width="50dp" />

    <EditText
        android:id="@+id/wspYb"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/wspXb"
        android:layout_alignBottom="@+id/wspXb"
        android:layout_alignLeft="@+id/wspYa"
        android:ems="10"
        android:inputType="numberDecimal"
        android:width="50dp" />

    <TextView
        android:id="@+id/ywynik"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/przelicz"
        android:layout_marginRight="33dp"
        android:layout_marginTop="24dp"
        android:layout_toLeftOf="@+id/wynik"
        android:text="y="
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <Button
        android:id="@+id/przelicz"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/wspXb"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="24dp"
        android:text="Przelicz" />

    <EditText
        android:id="@+id/wspXa"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/literaB"
        android:layout_centerHorizontal="true"
        android:ems="10"
        android:inputType="numberDecimal"
        android:width="50dp" />

    <EditText
        android:id="@+id/wspXb"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/literaB"
        android:layout_alignLeft="@+id/wspXa"
        android:ems="10"
        android:inputType="numberDecimal"
        android:width="50dp" >

        <requestFocus />
    </EditText>

    <TextView
        android:id="@+id/literaB"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/literaA"
        android:layout_marginRight="18dp"
        android:layout_marginTop="33dp"
        android:layout_toLeftOf="@+id/przelicz"
        android:text="Punkt B:"
        android:textSize="20sp" />

    <TextView
        android:id="@+id/literaA"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/literaB"
        android:layout_alignParentTop="true"
        android:layout_marginTop="56dp"
        android:text="Punkt A:"
        android:textSize="20sp" />

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/wspXa"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="14dp"
        android:text="X"
        android:textSize="22sp" />

    <TextView
        android:id="@+id/TextView01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textView1"
        android:layout_alignBottom="@+id/textView1"
        android:layout_alignLeft="@+id/wspYa"
        android:layout_marginLeft="16dp"
        android:text="Y"
        android:textSize="22sp" />

    <TextView
        android:id="@+id/wynik"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/ywynik"
        android:layout_alignRight="@+id/wspYb"
        android:layout_alignTop="@+id/ywynik"
        android:layout_toRightOf="@+id/literaA"
        android:textAppearance="?android:attr/textAppearanceLarge" />


</RelativeLayout>

Answer 1

您的清单的活动的Java类名称为activity_main。将其更改为Funkcja，这是您活动的实际Java类名称。

Answer 2

在您的清单中，您的主要活动名称为：

android:name=".activity_main"

将其更改为：

android:name=".Funkcja"

无法实例化主要活动 - ClassNotFound

2 个答案: