Question

嘿伙计们，我对android很新。我认为第一个应用程序的好主意是计算器。我完全安装并正确编译了该应用程序。但是，当我在我的设备上运行时，它会强行关闭。我想我的AndroidManifest.xml文件可能存在问题，但我不知道它是什么。

这可能是java代码：

import android.os.Bundle;
import android.app.Activity;
import android.text.Editable;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

import com.awesomeapps.misael.simplecalculator.R;

public class MainActivity extends Activity implements View.OnClickListener{
    Button one, two, three, four, five, six, seven, eight, nine, zero, add, sub, mul, div, cancel, equal;
    EditText disp;
    int op1;
    int op2;
    String optr;

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

        one = (Button) findViewById(R.id.one);
        two = (Button) findViewById(R.id.two);
        three = (Button) findViewById(R.id.three);
        four = (Button) findViewById(R.id.four);
        five = (Button) findViewById(R.id.five);
        six = (Button) findViewById(R.id.six);
        seven = (Button) findViewById(R.id.seven);
        eight = (Button) findViewById(R.id.eight);
        nine = (Button) findViewById(R.id.nine);
        zero = (Button) findViewById(R.id.zero);
        add = (Button) findViewById(R.id.add);
        sub = (Button) findViewById(R.id.sub);
        mul = (Button) findViewById(R.id.mul);
        div = (Button) findViewById(R.id.div);
        cancel = (Button) findViewById(R.id.cancel);
        equal = (Button) findViewById(R.id.equal);

        disp = (EditText) findViewById(R.id.editText);

        try {
            one.setOnClickListener(this);
            two.setOnClickListener(this);
            three.setOnClickListener(this);
            four.setOnClickListener(this);
            five.setOnClickListener(this);
            six.setOnClickListener(this);
            seven.setOnClickListener(this);
            eight.setOnClickListener(this);
            nine.setOnClickListener(this);
            zero.setOnClickListener(this);
            cancel.setOnClickListener(this);
            add.setOnClickListener(this);
            sub.setOnClickListener(this);
            mul.setOnClickListener(this);
            div.setOnClickListener(this);
            equal.setOnClickListener(this);
        } catch (Exception e) {
        }
    }

    public void operation() {
        if (optr.equals("+")) {
            op2 = Integer.parseInt(disp.getText().toString());
            disp.setText("");
            op1 = op1 + op2;
            disp.setText("Result: " + Integer.toString(op1));
        } else if (optr.equals("-")) {
            op2 = Integer.parseInt(disp.getText().toString());
            disp.setText("");
            op1 = op1 - op2;
            disp.setText("Result" + Integer.toString(op1));
        } else if (optr.equals("*")) {
            op2 = Integer.parseInt(disp.getText().toString());
            disp.setText("");
            op1 = op1 * op2;
            disp.setText("Result" + Integer.toString(op1));
        } else if (optr.equals("/")) {
            op2 = Integer.parseInt(disp.getText().toString());
            disp.setText("");
            op1 = op1 / op2;
            disp.setText("Result" + Integer.toString(op1));
        }
    }

    @Override
    public void onClick(View arg0) {
        Editable str = disp.getText();
        switch (arg0.getId()) {
            case R.id.one:
                if (op2 != 0) {
                    op2 = 0;
                    disp.setText("");
                }
                str = str.append(two.getText());
                disp.setText(str);
                break;
            case R.id.two:
                if (op2 != 0) {
                    op2 = 0;
                }
                str = str.append(two.getText());
                disp.setText(str);
            case R.id.three:
                if (op2 != 0) {
                    op2 = 0;
                }
                str = str.append(three.getText());
                disp.setText(str);
                break;
            case R.id.four:
                if (op2 != 0) {
                    op2 = 0;
                }
                str = str.append(four.getText());
                disp.setText(str);
                break;
            case R.id.five:
                if (op2 != 0) {
                    op2 = 0;
                }
                str = str.append(five.getText());
                disp.setText(str);
                break;
            case R.id.six:
                if (op2 != 0) {
                    op2 = 0;
                }
                str = str.append(six.getText());
                disp.setText(str);
                break;
            case R.id.seven:
                if (op2 != 0) {
                    op2 = 0;
                }
                str = str.append(eight.getText());
                disp.setText(str);
                break;
            case R.id.eight:
                if (op2 != 0) {
                    op2 = 0;
                }
                str = str.append(nine.getText());
                disp.setText(str);
                break;
            case R.id.nine:
                if (op2 != 0) {
                    op2 = 0;
                }
                str = str.append(zero.getText());
                disp.setText(str);
                break;
            case R.id.cancel:
                op1 = 0;
                op2 = 0;
                disp.setText("");
                disp.setHint("Perform Operation");
                break;
            case R.id.add:
                optr = "+";
                if (op1 == 0) {
                    op1 = Integer.parseInt(disp.getText().toString());
                    disp.setText("");
                } else if (op2 != 0) {
                    op2 = 0;
                    disp.setText("");
                } else {
                    op2 = Integer.parseInt(disp.getText().toString());
                    disp.setText("");
                    op1 = op1 + op2;
                    disp.setText("Result" + Integer.toString(op1));
                }
                break;
            case R.id.sub:
                optr = "-";
                if (op1 == 0) {
                    op1 = Integer.parseInt(disp.getText().toString());
                    disp.setText("");
                } else if (op2 != 0) {
                    op2 = 0;
                    disp.setText("");
                } else {
                    op2 = Integer.parseInt(disp.getText().toString());
                    disp.setText("");
                    op1 = op1 - op2;
                    disp.setText("Result" + Integer.toString(op1));
                }
                break;
            case R.id.mul:
                optr = "*";
                if (op1 == 0) {
                    op1 = Integer.parseInt(disp.getText().toString());
                    disp.setText("");
                } else if (op2 != 0) {
                    op2 = 0;
                    disp.setText("");
                } else {
                    op2 = Integer.parseInt(disp.getText().toString());
                    disp.setText("");
                    op1 = op1 * op2;
                    disp.setText("Result" + Integer.toString(op1));
                }
                break;
            case R.id.div:
                optr = "/";
                if (op1 == 0) {
                    op1 = Integer.parseInt(disp.getText().toString());
                    disp.setText("");
                } else if (op2 != 0) {
                    op2 = 0;
                    disp.setText("");
                } else {
                    op2 = Integer.parseInt(disp.getText().toString());
                    disp.setText("");
                    op1 = op1 / op2;
                    disp.setText("Result" + Integer.toString(op1));
                }
                break;
            case R.id.equal:
                if (optr.equals(null)) {
                    if (op2 != 0) {
                        if (optr.equals("+")) {
                            disp.setText("");
                    /*op1 = op1+op2;*/
                            disp.setText("Result:" + Integer.toString(op1));
                        } else if (optr.equals("-")) {
                            disp.setText("");/*
                    op1 = op1 - op2;*/
                            disp.setText("Result" + Integer.toString(op1));
                        } else if (optr.equals("*")) {
                            disp.setText("");/*
                    op1 = op1*op2;*/
                            disp.setText("Result" + Integer.toString(op1));
                        } else if (optr.equals("/")) {
                            disp.setText("");/*
                    op1=op1/op2;*/
                            disp.setText("Result" + Integer.toString(op1));
                        }
                    } else {
                        operation();
                    }
                }
                break;
        }
    }
}

这是我的AndroidManifest xml文件：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.awesomeapps.misael.simplecalculator">

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

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

</manifest>

哦，我也收到此错误消息：

05-29 21:48:03.091 10728-10728/com.awesomeapps.misael.simplecalculator E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.awesomeapps.misael.simplecalculator, PID: 10728
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.awesomeapps.misael.simplecalculator/com.awesomeapps.misael.simplecalculator.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.awesomeapps.misael.simplecalculator.MainActivity" on path: DexPathList[[zip file "/data/app/com.awesomeapps.misael.simplecalculator-1/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2641)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2855)
at android.app.ActivityThread.access$900(ActivityThread.java:181)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1474)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:6117)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.awesomeapps.misael.simplecalculator.MainActivity" on path: DexPathList[[zip file "/data/app/com.awesomeapps.misael.simplecalculator-1/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
at android.app.Instrumentation.newActivity(Instrumentation.java:1079)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2631)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2855) 
at android.app.ActivityThread.access$900(ActivityThread.java:181) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1474) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:145) 
at android.app.ActivityThread.main(ActivityThread.java:6117) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194) 
Suppressed: java.lang.ClassNotFoundException: com.awesomeapps.misael.simplecalculator.MainActivity
at java.lang.Class.classForName(Native Method)
at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
... 13 more
Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available

如果有人可以通过告诉我在我的java代码或android manifest xml文件中修复什么来取悦。或许它的东西完全不同。

任何帮助都会很棒，非常感谢！谢谢！：）

Answer 1

在 MainActivity 类的顶部添加以下行：

package com.awesomeapps.misael.simplecalculator;

在此之后清理并重建您的项目。

Answer 2

我试图运行您的代码并将所有内容粘贴到新项目中。我接下来做的是：

1）删除了这个

import com.awesomeapps.misael.simplecalculator.R;

2）将我的包导入MainActivity.java的第一行（我猜你的情况就是这样）

package com.awesomeapps.misael.simplecalculator;

我没有触及清单文件。然后它结果运行没有任何错误。

但是，我应该提一下代码中有很多错误。至少，它没有显示结果，按下它们时某些数字按钮输入的值不正确。运行代码并修复错误。最后，如果您在布局中包含一些可解释如何使用计算器的textview，那就太棒了。快乐的编码：）

Answer 3

将包名添加到MainActivity

<?= $form->field($model, 'color', [
    'template' => "{input}"
    ])->input('color',['class'=>"input_class"]) ?>

删除此行package com.awesomeapps.misael.simplecalculator;

删除构建文件夹清理并重建您的项目。希望它能解决你的问题。

Answer 4

如果您想在项目中启用multi-dex，请转到gradle.builder

并在您的依赖项中添加此内容

    dependencies {
      compile 'com.android.support:multidex:1.0.0'}

然后你必须添加

    defaultConfig {
     ...
    minSdkVersion 14
    targetSdkVersion 21
    ...

    // Enabling multidex support.
       multiDexEnabled true}

然后打开一个类并将其扩展到Application如果你的应用程序使用扩展Application类，你可以覆盖oncrete（）方法并调用。

     //add this code into your application class
public class MyApplication extends Application {
       // public Context context;
@Override
public void onCreate( ) {
    super.onCreate();
  }
}
@Override
protected void attachBaseContext(Context newBase) {
    super.attachBaseContext(newBase);
    MultiDex.install(this);
}

启用multidex。

最后加入你的清单

   <?xml version="1.0" encoding="utf-8"?>
   <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.android.multidex.myapplication">
   <application
   ...
   android:name=".MyApplication"">
   ...
  </application>
  </manifest>

AndroidManifes xml的问题。 App force在运行时关闭

4 个答案: