本人刚开始学习android,跟着书写了个程序,这个程序是会有一个东西随着手指拖动而移动,编译完没有问题,但是在手机上运行的时候却是意外停止,错误显示在了MainActivity的第27行,我真不知道哪里错,代码和书上写的一模一样,求大神指导MainActivity的代码:package com.example.test34;import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.FrameLayout;public class MainActivity extends Activity { @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FrameLayout frameLayout=(FrameLayout)findViewById(R.id.mylayout);
final RabbitView rabbit=new RabbitView(MainActivity.this);
rabbit.setOnTouchListener(new OnTouchListener(){
@Override
public boolean onTouch(View v,MotionEvent event){
rabbit.bitmapX=event.getX();
rabbit.bitmapY=event.getY();
rabbit.invalidate();
return true;
}
});
frameLayout.addView(rabbit);
}
@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;
}
}
RabbitView.java代码
package com.example.test34;import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.view.View;
public class RabbitView extends View {
public float bitmapX;
public float bitmapY;
public RabbitView(Context context){
super(context);
bitmapX=750;
bitmapY=500;
}
@Override
protected void onDraw(Canvas canvas){
super.onDraw(canvas);
Paint paint=new Paint();
Bitmap bitmap=BitmapFactory.decodeResource(this.getResources(),R.drawable.ic_launcher);
canvas.drawBitmap(bitmap,bitmapX,bitmapY,paint);
if(bitmap.isRecycled()){
bitmap.recycle();
}
}}
activity_main代码
<FrameLayout 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=".MainActivity"
android:background="@drawable/background"
android:id="@+id/mylayout" ></FrameLayout>
AndroidEclipseJava
import android.os.Bundle;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.FrameLayout;public class MainActivity extends Activity { @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FrameLayout frameLayout=(FrameLayout)findViewById(R.id.mylayout);
final RabbitView rabbit=new RabbitView(MainActivity.this);
rabbit.setOnTouchListener(new OnTouchListener(){
@Override
public boolean onTouch(View v,MotionEvent event){
rabbit.bitmapX=event.getX();
rabbit.bitmapY=event.getY();
rabbit.invalidate();
return true;
}
});
frameLayout.addView(rabbit);
}
@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;
}
}
RabbitView.java代码
package com.example.test34;import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.view.View;
public class RabbitView extends View {
public float bitmapX;
public float bitmapY;
public RabbitView(Context context){
super(context);
bitmapX=750;
bitmapY=500;
}
@Override
protected void onDraw(Canvas canvas){
super.onDraw(canvas);
Paint paint=new Paint();
Bitmap bitmap=BitmapFactory.decodeResource(this.getResources(),R.drawable.ic_launcher);
canvas.drawBitmap(bitmap,bitmapX,bitmapY,paint);
if(bitmap.isRecycled()){
bitmap.recycle();
}
}}
activity_main代码
<FrameLayout 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=".MainActivity"
android:background="@drawable/background"
android:id="@+id/mylayout" ></FrameLayout>
AndroidEclipseJava
解决方案 »
免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货