Android 自定义View
Android 自定义View为MyCustomView。在MyCustomView画了一个Rect，
颜色为Green，和一个为红色的文字。
public
class
MyCustomView
extends
View{
private
Paint mPaint;
private
Context mContext;
private
static
final
String mString =
"Hello world!"
;
public
MyCustomView(Context context) {
super
(context);
// TODO Auto-generated constructor stub
}
public
MyCustomView(Context context, AttributeSet attr) {
super
(context,attr);
// TODO Auto-generated constructor stub
}
@Override
protected
void
onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super
.onDraw(canvas);
mPaint =
new
Paint();
mPaint.setColor(Color.GREEN);
mPaint.setStyle(Style.FILL);
canvas.drawRect(
new
Rect(
10
,
10
,
300
,
500
), mPaint);
mPaint.setColor(Color.RED);
canvas.drawText(mString,
50
,
550
, mPaint);
}
}
|
将自定义的View添加到activity_main的Layout中
<?xml version=
"1.0"
encoding=
"utf-8"
?>
<LinearLayout xmlns:android=
"http://schemas.android.com/apk/res/android"
android:orientation=
"vertical"
android:layout_width=
"fill_parent"
android:layout_height=
"fill_parent"
>
<TextView
android:layout_width=
"fill_parent"
android:layout_height=
"wrap_content"
android:text=
"@string/hello_world"
/>
<com.example.customview.MyCustomView
android:layout_width=
"fill_parent"
android:layout_height=
"fill_parent"
/>
</LinearLayout>
|
其中Layout中的<com.example.customview.MyCustomView />就是对该自定义控件的使用。
二、为MyCustomView添加自定义属性
在value文件夹下建attrs.xml文件。 定义了两个属性，分别为文本颜色和文本大小。
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<?xml version=
"1.0"
encoding=
"utf-8"
?>
<resources>
<declare-styleable name=
"MyView"
>
<attr name=
"textColor"
format=
"color"
/>
<attr name=
"textSize"
format=
"dimension"
/>
</declare-styleable>
</resources>
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MyCustomView类更改如下
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public
class
MyCustomView
extends
View {
private
Paint mPaint;
private
Context mContext;
private
static
final
String mString =
"Hello world!"
;
public
MyCustomView(Context context) {
super
(context);
mPaint =
new
Paint();
}
public
MyCustomView(Context context, AttributeSet attr) {
super
(context, attr);
mPaint =
new
Paint();
TypedArray array = context.obtainStyledAttributes(attr, R.styleable.MyView);
int
textColor = array.getColor(R.styleable.MyView_textColor,
0XFFFFFFFF
);
float
textSize = array.getDimension(R.styleable.MyView_textSize,
30
);
mPaint.setColor(textColor);
mPaint.setTextSize(textSize);
array.recycle();
//TypedArray通常最后调用 .recycle() 方法，为了保持以后使用该属性一致性！
}
@Override
protected
void
onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super
.onDraw(canvas);
mPaint.setStyle(Style.FILL);
canvas.drawRect(
new
Rect(
10
,
10
,
300
,
500
), mPaint);
mPaint.setColor(Color.RED);
canvas.drawText(mString,
50
,
550
, mPaint);
}
}
|
Layout更改如下
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<RelativeLayout xmlns:android=
"http://schemas.android.com/apk/res/android"
xmlns:tools=
"http://schemas.android.com/tools"
xmlns:test=
"http://schemas.android.com/apk/res/com.example.customviewdemo"
android:layout_width=
"match_parent"
android:layout_height=
"match_parent"
tools:context=
".MainActivity"
>
<com.example.customviewdemo.MyCustomView
android:layout_width=
"fill_parent"
android:layout_height=
"fill_parent"
test:textColor=
"#00ff00"
test:textSize=
"20sp"
/>
</RelativeLayout>
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注意：1. xmlns:test=http://schemas.android.com/apk/res/com.example.customviewdemo test是自定义的，名字随便取。com.example.customviewdemo 是包名。
2. test:textColor="#00ff00" test:textSize="20sp" 这两个就是要调用的自定义属性。
效果如下图：
本文转自Work Hard Work Smart博客园博客，原文链接：http://www.cnblogs.com/linlf03/archive/2013/03/18/2958109.html，如需转载请自行联系原作者
