自定义控件

自定义属性

1.在values新建文件attr

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="MyButtonAttrs">
<!-- dimension -->
<attr name="MyWidth" format="dimension"/>
<!-- enum -->
<attr name="MyVisibility">
<enum name="visible" value="0" />
<enum name="invisible" value="1" />
<enum name="gone" value="2" />
</attr>
<!-- boolean -->
<attr name="MyBoolean" format="boolean" />
<!-- reference :drawable -->
<attr name="Mybackground" format="reference|color" />
<attr name="MyTextColor" format="color" />
</declare-styleable>
</resources>

2.在布局文件中使用

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:steven="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<com.example.lessontest.ui.MyButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
steven:MyWidth="10dp"
steven:MyVisibility="invisible"
steven:Mybackground="@drawable/ic_launcher"
steven:MyBoolean="true"
/>
</RelativeLayout>

命名空间 xmlns:steven="http://schemas.android.com/apk/res-auto"

3.代码中获取属性值

public class MyButton extends View
{
/** 默认属性 **/
int MyWidth = 10; //
int MyVisibility = 1;
boolean MyBoolean = false;
int Mybackground = R.drawable.ic_launcher;

/** 代码创建 **/
public MyButton(Context context)
{
this(context, null);
}

/** xml创建，自定义属性 **/
public MyButton(Context context, AttributeSet attrs)
{
this(context, attrs, 0);
}

/** xml创建，自定义属性，有style **/
public MyButton(Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);

// 获取配置的自定义属性-------------------
TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.MyButtonAttrs);
MyWidth = a
.getDimensionPixelSize(R.styleable.MyButtonAttrs_MyWidth, -1);
float dimension = a.getDimension(R.styleable.MyButtonAttrs_MyWidth, -1);
System.out.println(dimension + "dimension");
MyVisibility = a.getInt(R.styleable.MyButtonAttrs_MyVisibility, 5);
MyBoolean = a.getBoolean(R.styleable.MyButtonAttrs_MyBoolean, false);
Mybackground = a.getResourceId(R.styleable.MyButtonAttrs_Mybackground,
-1);

System.out.println("" + toString());
}

@Override
public String toString()
{
return "MyButton [MyWidth=" + MyWidth + ", MyVisibility="
+ MyVisibility + ", MyBoolean=" + MyBoolean + ", Mybackground="
+ Mybackground + "]";
}

/**
* onMessure onLayout(ViewGroup) onDraw
*
* View onMeasure() (在这个方法里指定自己的宽高) ->onDraw() (绘制自己的内容)
*
* ViewGroup onMeasure() (指定自己的宽高, 所有子View的宽高)-> onLayout() (摆放所有子View) ->
* onDraw() (绘制内容)
*
*/
@Override
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
}
}

SmartIamgeView（loopj版）ImageView扩展：

加载图片，继承了ImageView，支持url加载图片，处理listview跳图的问题、oom等问题

地址:https://github.com/loopj/android-smart-image-view

ScrollListView（偶尔看看II eoe）ListView扩展：

listView滑动的时候每个item添加动画酷炫的效果

<span style="font-size:18px;">import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListView;

public class ScrollListView extends ListView implements OnScrollListener
{
/**
* 下滑时刷新
*/
private final int DOWNREFRESH = 1;
/**
* 上滑是刷新
*/
private final int UPREFRESH = 0;
/**
* 初始状态下第一个 条目
*/
private int startfirstItemIndex;
/**
* 初始状态下最后一个 条目
*/
private int startlastItemIndex;
/**
* 滑动后的第一个条目
*/
private int endfirstItemIndex;
/**
* 滑动后的最后一个条目
*/
private int endlastItemIndex;
private View view;
private Animation animation;
private Handler handler;
private Runnable run;
private Message message;
public ScrollListView(Context context)
{

this(context, null);
}
public ScrollListView(Context context, AttributeSet attrs)
{
this(context, attrs, android.R.attr.listViewStyle);

}
public ScrollListView(final Context context, AttributeSet attrs,
int defStyle)
{
super(context, attrs, defStyle);
setOnScrollListener(this);

handler = new Handler() {

@Override
public void handleMessage(Message msg)
{
super.handleMessage(msg);
int result = (Integer) msg.obj;
switch (result)
{
case DOWNREFRESH:
{
// 获得最后一个item
view = getChildAt(getChildCount() - 1);
break;
}
case UPREFRESH:
{
// 获得第一个item
view = getChildAt(0);
break;
}
default:
break;
}
if (null != view)
{
// 加载动画
animation = AnimationUtils.loadAnimation(context,
R.anim.select_sacle);
view.startAnimation(animation);
}
}
};

}
@Override
public void onScroll(AbsListView arg0, int arg1, int arg2, int arg3)
{
// TODO Auto-generated method stub
startfirstItemIndex = arg1;
startlastItemIndex = arg1 + arg2 - 1;
// 判断向下或者向上滑动了
if ((endfirstItemIndex > startfirstItemIndex)
&& (endfirstItemIndex > 0))
{
RunThread(UPREFRESH);
} else if ((endlastItemIndex < startlastItemIndex)
&& (endlastItemIndex > 0))
{
RunThread(DOWNREFRESH);
}
endfirstItemIndex = startfirstItemIndex;
endlastItemIndex = startlastItemIndex;
}
private void RunThread(final int state)
{
run = new Runnable() {

@Override
public void run()
{
message = handler.obtainMessage(1, state);
handler.sendMessage(message);
}
};
run.run();
}
@Override
public void onScrollStateChanged(AbsListView arg0, int arg1)
{

}
}</span><span style="font-size: 24px;">
</span>