Android - 自定义控件和属性(attr和TypedArray)

http://blog.csdn.net/zjh_1110120/article/details/50976027

1.attr format 取值类型

以ShapeView 为例

<declare-styleable name="ShapeViewStyle">
<attr name="viewWidth" format="dimension|reference"/>
<attr name="viewHeight" format="dimension|reference"/>
<attr name="viewColor" format="color|reference"/>

<attr name="viewShape" format="enum">
<enum name="rect" value="0"/>
<enum name="oval" value="1"/>
<enum name="line" value="2"/>
</attr>

<attr name="lineWidth" format="dimension|reference"/>
<attr name="lineDashWidth" format="dimension|reference"/>
<attr name="lineDashGap" format="dimension|reference"/>
</declare-styleable>

<com.example.administrator.llab.view.ShapeView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
app:viewColor="@color/red"
app:viewHeight="50dp"
app:viewShape="oval"
app:viewWidth="50dp"/>

TypedArray 详解

http://blog.csdn.net/zjh_1110120/article/details/50986589

大体意思是：TypedArray 是一个数组容器，在这个容器中装由

obtainStyledAttributes(AttributeSet, int[], int, int)

或者

obtainAttributes(AttributeSet, int[])

函数获取到的属性值。用完之后记得调用

recycle()

函数回收资源。索引值用来获取 Attributes 对应的属性值（这个 Attributes 将会被传入

obtainStyledAttributes()

函数）。

private void init(Context context, AttributeSet attrs, int defStyleAttr) {
this.mContext = context;

TypedArray typedArray = getContext().obtainStyledAttributes(attrs, R.styleable.ShapeViewStyle, defStyleAttr, 0);

viewWidth = (int) typedArray.getDimension(R.styleable.ShapeViewStyle_viewWidth, viewWidth);
viewHeight = (int) typedArray.getDimension(R.styleable.ShapeViewStyle_viewHeight, viewHeight);
viewColor = typedArray.getColor(R.styleable.ShapeViewStyle_viewColor, viewColor);

lineWidth = (int) typedArray.getDimension(R.styleable.ShapeViewStyle_lineWidth, lineWidth);
lineDashWidth = (int) typedArray.getDimension(R.styleable.ShapeViewStyle_lineDashWidth, lineDashWidth);
lineDashGap = (int) typedArray.getDimension(R.styleable.ShapeViewStyle_lineDashGap, lineDashGap);

int shape = typedArray.getInt(R.styleable.ShapeViewStyle_viewShape, Shape.rect.ordinal());
for (Shape shapeValue: Shape.values()) {
if (shapeValue.ordinal() == shape) {
viewShape = shapeValue;
break;
}
}

setImageDrawable(createShapeView());
}

private LayerDrawable createShapeView() {
GradientDrawable gradientDrawable = new GradientDrawable();
gradientDrawable.setColor(viewColor);
gradientDrawable.setSize(viewWidth, viewHeight);

switch (viewShape) {
case rect:
gradientDrawable.setShape(GradientDrawable.RECTANGLE);
break;
case oval:
gradientDrawable.setShape(GradientDrawable.OVAL);
break;
case line:
gradientDrawable.setShape(GradientDrawable.LINE);
gradientDrawable.setStroke(lineWidth, viewColor, lineDashWidth, lineDashGap);
break;
}
return new LayerDrawable(new Drawable[]{gradientDrawable});
}