自定义View的注意点
最近在家无事，开始学习android。自己做了一个自定义的View，布署到main.xml上去，却发现跑的时候老是出现错误。
后来发现，原来是集成View的时候没有写上父类3个参数的构造方法。
估计其内部默认情况下会调用那个构造方法吧。
贴上代码：
main.xml
<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="fill_parent" android:layout_height="fill_parent"><com.ant.memory.PhotoViewandroid:id="@+id/photo" android:layout_width="fill_parent"android:background="#0000ff"android:layout_height="fill_parent" tileSize="24" /></FrameLayout>
PhotoView:
public class PhotoView extends View {/* * 这个constructor是必须的要的，如果你想将这个View布署道main.xml上 */public PhotoView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);}@Overridepublic void draw(Canvas canvas) {// TODO Auto-generated method stubsuper.draw(canvas);InputStream is=getResources().openRawResource(R.drawable.back);Bitmap bitmap=BitmapFactory.decodeStream(is);Paint paint=new Paint();canvas.drawBitmap(bitmap, 50, 50, paint);}}
Memory.java:
package com.ant.memory;import android.app.Activity;import android.os.Bundle;import android.view.Window;public class Memory extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); PhotoView photoView; setContentView(R.layout.main); photoView=(PhotoView) findViewById(R.id.photo); }}
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