MainActivity代碼: android
package com.example.demo_layout;
import android.os.Bundle;
import android.app.Activity;
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);
setContentView(R.layout.activity_main);
FrameLayout frameLayout = (FrameLayout)findViewById(R.id.mylayout);
final RabbitView rabbit = new RabbitView(MainActivity.this);
rabbit.setOnTouchListener(new OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
rabbit.bitmapX = event.getX();
rabbit.bitmapY = event.getY();
rabbit.invalidate(); //重繪
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;
}
} canvas
自定義一個view app
package com.example.demo_layout;
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();
//根據圖片生成位圖對象
Bitmap bitmap = BitmapFactory.decodeResource(this.getResources(), R.drawable.rabbit);
//繪製小兔子
canvas.drawBitmap(bitmap, bitmapX, bitmapY, paint);
//判斷圖片是否回收,若是是,強制回收
if(bitmap.isRecycled()){
bitmap.recycle();
}
}
} ide
xml文件 this
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/background"
android:id="@+id/mylayout"
>
</FrameLayout> code
圖片:res/drawable文件夾裏面 xml
真相 對象