Android自定义属性的使用

在android中我们习惯了在XML布局文件中，进行控件属性的设置，由于控件默认提供的属性数量有限，为了增加属性我们可以给控件添加一些自定义的属性，下面来讲一下为控件添加自定义属性的几个步骤。

1>在res/values文件下添加一个attrs.xml文件(没有的话)如下:

<?xml version="1.0" encoding="utf-8"?>
<resources>
<!--添加了一个ImageTextButton的属性集  -->
<declare-styleable name="ImageTextButton">
<attr format="reference" name="iconImage" />
<attr format="reference" name="bkImage" />
<attr format="integer" name="borderLeft" />
<attr format="integer" name="borderRight" />
<attr format="integer" name="borderTop" />
<attr format="integer" name="borderBottom" />
<attr format="integer" name="buttonstate" />
<attr name="iconLocation">
<enum name="center" value="0" />
<enum name="left" value="1" />
<enum name="right" value="2" />
</attr>
</declare-styleable>
</resources>

2>在相关的XML布局文件中使用自定义的属性:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:mux="http://schemas.android.com/apk/res/com.shareboard"
android:layout_width="530dp"
android:layout_height="320dp"
android:background="@color/dlgBg"
android:orientation="vertical" >

<!--com.shareboard 为工程所在包  -->

<com.shareboard.uicontrols.ImageTextButton
android:id="@+id/btnCancel"
android:layout_width="100sp"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_marginRight="20dp"
mux:bkImage="@drawable/cell_bkgnd"
mux:buttonstate="2"
android:text="@string/btn_cancel"
android:textColor="@color/btnText"
android:textSize="@dimen/btnText" />

<com.shareboard.uicontrols.ImageTextButton
android:id="@+id/btnDone"
android:layout_width="100sp"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_marginLeft="@dimen/btnMargin"
mux:bkImage="@drawable/cell_bkgnd"
mux:buttonstate="2"
android:text="@string/btn_done"
android:textColor="@color/btnText"
android:textSize="@dimen/btnText" />
</LinearLayout>

3>在代码中获取自定义的属性值:

public final class ImageTextButton extends Button {

private int mIconId;
private int mBkimgId;
private int mBorderLeft = 10;
private int mBorderRight = 10;
private int mBorderTop = 10;
private int mBorderBottom = 10;
private int mnButtonState = 4;
private int mIconLocation = 0;
private boolean mbChecked = false;

public ImageTextButton(Context context) {
super(context);
setClickable(true);
}

public ImageTextButton(Context context, AttributeSet attrs) {
super(context, attrs);
readAttrs(context, attrs);
setClickable(true);
}

private void readAttrs(Context context, AttributeSet attrs) {
TypedArray types = context.obtainStyledAttributes(attrs,
R.styleable.ImageTextButton);
final int count = types.getIndexCount();
for (int i = 0; i < count; ++i) {
int attr = types.getIndex(i);
switch (attr) {
case R.styleable.ImageTextButton_iconImage:
mIconId = types.getResourceId(attr, 0);
break;
case R.styleable.ImageTextButton_bkImage:
mBkimgId = types.getResourceId(attr, 0);
break;
case R.styleable.ImageTextButton_borderLeft:
mBorderLeft = types.getInteger(attr, 10);
break;
case R.styleable.ImageTextButton_borderRight:
mBorderRight = types.getInteger(attr, 10);
break;
case R.styleable.ImageTextButton_borderTop:
mBorderTop = types.getInteger(attr, 10);
break;
case R.styleable.ImageTextButton_borderBottom:
mBorderBottom = types.getInteger(attr, 10);
break;
case R.styleable.ImageTextButton_iconLocation:
mIconLocation = types.getInteger(attr, 0);
break;
case R.styleable.ImageTextButton_buttonstate:
mnButtonState = types.getInteger(attr, 4);
break;
}
}
types.recycle();
}

}

好了这就完成了自定义属性的定义和使用。