嘗試創建XML FrameLayout，Android應用不斷崩潰

Question

我在我的android應用程序的xml中使用了relativelayout，但已決定切換到framelayout，以便可以使imageView成為另一個imageView的子級。 問題是，盡管該游戲到目前為止還可以運行，但是由於我將xml編輯為幀布局，現在它崩潰了。 誰能說出現在為什么崩潰了？ 我確定我在imageView定義中仍然使用了我不應該使用的東西，但無法弄清楚它是什么。

這是我的xml文件：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@layout/activity_main"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/background"
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=".MainActivity" >

<com.cannibal_photographer.Person
    android:id="@+id/personView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="335dp"
    android:src="@drawable/greensquare" />

<com.cannibal_photographer.Boat
    android:id="@+id/boatimageView"
    android:layout_width="78dp"
    android:layout_height="130dp"
    android:layout_marginLeft="105dp"
    android:layout_marginTop="180dp"
    android:src="@drawable/boat" />

</FrameLayout>

這是MainActivity：

package com.cannibal_photographer;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);     
    Boat boatobject = (Boat)findViewById(R.id.boatimageView);   
    Person personobject = (Person)findViewById(R.id.personView1);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

這是船課：

package com.cannibal_photographer;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.ImageView;

public class Boat extends ImageView {

boolean state = true;

public Boat(Context context) {
    super(context);
    init();
}

 public Boat(Context context, AttributeSet attrs)
    {
        super(context, attrs);
        init();
    }

 public Boat(Context context, AttributeSet attrs, int defStyle)
    {
        super(context, attrs, defStyle);
        init();
    }

private void init()
{
    this.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick (View v) {
            if (state) {
                moveBoat(-290);
            } else {
                moveBoat(290);
            }
        }
    });
}

//TranslateAnimation animation;
//TranslateAnimation animation2;

public void moveBoat(int amount){
    /*
    animation = new TranslateAnimation(0, 0, 0, amount);
    animation.setDuration(250);
    animation.setFillAfter(true);
    this.startAnimation(animation);
    */
    this.offsetTopAndBottom(amount);
    state = !state;
}
}

這是人類：

package com.cannibal_photographer;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.ImageView;

public class Person extends ImageView {

boolean state = true;

public Person(Context context) {
    super(context);
    init();
}

 public Person(Context context, AttributeSet attrs)
    {
        super(context, attrs);
        init();
    }

 public Person(Context context, AttributeSet attrs, int defStyle)
    {
        super(context, attrs, defStyle);
        init();
    }

private void init()
{
    this.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick (View v) {
            if (state) {
                movePerson(325,-230);
            } else {
                movePerson(-325,230);
            }
        }
    });


}

public void movePerson(int x, int y)
{
    this.offsetLeftAndRight(x);
    this.offsetTopAndBottom(y);

    state = !state;
}

}

這是堆棧跟蹤：

10-14 23:10:10.985: E/AndroidRuntime(932): FATAL EXCEPTION: main
10-14 23:10:10.985: E/AndroidRuntime(932): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.cannibal_photographer/com.cannibal_photographer.MainActivity}: java.lang.ClassCastException: com.cannibal_photographer.Person cannot be cast to com.cannibal_photographer.Boat
10-14 23:10:10.985: E/AndroidRuntime(932):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
10-14 23:10:10.985: E/AndroidRuntime(932):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
10-14 23:10:10.985: E/AndroidRuntime(932):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
10-14 23:10:10.985: E/AndroidRuntime(932):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
10-14 23:10:10.985: E/AndroidRuntime(932):  at android.os.Handler.dispatchMessage(Handler.java:99)
10-14 23:10:10.985: E/AndroidRuntime(932):  at android.os.Looper.loop(Looper.java:137)
10-14 23:10:10.985: E/AndroidRuntime(932):  at android.app.ActivityThread.main(ActivityThread.java:5041)
10-14 23:10:10.985: E/AndroidRuntime(932):  at java.lang.reflect.Method.invokeNative(Native Method)

Answer 1

問題是

**java.lang.ClassCastException:** com.cannibal_photographer.Person cannot be cast to com.cannibal_photographer.Boat 10-14 23:10:10.985: E/AndroidRuntime(932): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)

您正在嘗試將Person對象投射到Boat。 再次檢查您的代碼是否正確映射了XML ID。