Android中自定义属性基本步骤

这次只是说明最简单的自定义属性流程

1. 创建资源文件: resources/attr.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="test">
        <attr name="test" format="string" />
        <attr name="testArr" format="integer" />
    </declare-styleable>
</resources>

2. 自定义view类

public class MyTextView extends View{
    private static final String TAG = "MyTextView";

    public MyTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray ta = context.obtainStyledAttributes(attrs,R.styleable.test);
        String text = ta.getString(R.styleable.test_testArr);
        int textAttr = ta.getInteger(R.styleable.test_text, -1);
        Log.e(TAG, "text:"+text+",textAttr:"+textAttr);

        ta.recycle();
    }
}

3. 在布局文件中使用

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:yxm="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="org.xm.customview.MainActivity">

    <org.xm.customview.MyTextView
        android:layout_width="100dp"
        android:layout_height="200dp"
        yxm:testArr="20"
        yxm:text="xiaoming" />
</RelativeLayout>

注意

androidstudio中使用:xmlns:yxm="http://schemas.android.com/apk/res-auto"自动导入命名控件
如果在eclipse中要使用完成的包名,如:xmlns:sdf="http://schemas.android.com/apk/res/org.xm.customview"
给自定义属性添加参数使用制定定义的命名空间,例如:　yxm:testArr="20"

4. 实现自定义View,获取自定义属性

public class MyTextView extends View{
    private static final String TAG = "MyTextView";

    public MyTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray ta = context.obtainStyledAttributes(attrs,R.styleable.test);
        String text = ta.getString(R.styleable.test_text);
        int textAttr = ta.getInteger(R.styleable.test_testArr, -1);
        Log.e(TAG, "text:"+text+",textAttr:"+textAttr);

        ta.recycle();
    }
}

注意

R.styleable.test_text中 text_是自动添加的(必须写),然后添加属性名字text

所以最后会打印:text:xiaoming,textAttr:20, 还是很简单的吧!