[Rpm] Android xmlns Effects and Custom

 

xmlns: android = "http://schemas.android.com/apk/res/android's role is

 

这个是xml的命名空间，有了他，你就可以alt+/作为提示，提示你输入什么，不该输入什么，什么是对的，什么是错的，也可以理解为语法文件。或者语法判断器什么的

 

这个主要作用是在运行的时候那些控件的属性都是通过它来识别的，如果上面你写错了，不会有任何问题，但是在运行的时候就会有问题，提示你没有指定宽度等什么。这个是不用联网的。

 

 

 

    

 

  Android custom xmlns actually very simple syntax rules are:   

to Custom View when using an xml layout file need to add xmlns: prefix = http://schemas.android.com/apk/res/ your application package path .

  

Here is a simple example:

  

structure:

  

  

MyView.java

  

package kexc.myView;

  

import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.widget.TextView;
public class MyView extends TextView {
private String mString = "Welcome to Kesion's blog";

; public MyView (Context context, AttributeSet attrs) {
super (context, attrs);
TypedArray a = context.obtainStyledAttributes (attrs, < br /> R.styleable.MyView);
int textColor = a.getColor (R.styleable.MyView_textColor,
0XFFFFFFFF );
float textSize = a.getDimension (R.styleable.MyView_textSize, 36);
mString = a.getString (R.styleable.MyView_title);
setText (mString);
setTextSize (textSize) ;
setTextColor (textColor);
}
}

  

  

main.xml

  

xmlns: android = " http://schemas.android.com/apk/res/android " ;
xmlns: test = " http://schemas. android.com / apk / res / kexc.myView "
android: orientation =" vertical "
android : layout_width = "fill_parent"
android: layout_height = "fill_parent">
android: layout_width = "fill_parent"
android: layout_height = "wrap_content" ;
android: text = "@ string / hello"
/> < br /> android: layout_width = "fill_parent"
; android: layout_height = "fill_parent"
test: title = "wo shi text"
test: textSize = "20px" ;
test: textColor = "# fff"
/>

  

  

properties file value / attrs.xml

  

  

Run Results: