1、public static class ViewGroup.LayoutParams extends Object ?

java.lang.Object

???? android.view.ViewGroup.LayoutParams ? Class Overview

LayoutParams are used by views to tell their parents how they want to be laid out.

LayoutParams是ViewGroup的一個內(nèi)部類, 每個不同的ViewGroup都有自己的LayoutParams子類

DEMO:

//創(chuàng)建一個線性布局????
private?LinearLayout?mLayout;????
mLayout?=?(LinearLayout)?findViewById(R.id.layout);?
//現(xiàn)在要往mLayout里邊添加一個TextView????
????
TextView?textView?=?new?TextView(Activity01.this);????
textView.setText("Text?View?"?);????
//這里是設(shè)置?這個textView的布局?FILL_PARENT?WRAP_CONTENT?和在xml文件里邊設(shè)置是一樣的如????
/***/
????
//第一個參數(shù)為寬的設(shè)置，第二個參數(shù)為高的設(shè)置。????
LinearLayout.LayoutParams?p?=?new?LinearLayout.LayoutParams(????
LinearLayout.LayoutParams.FILL_PARENT,????
LinearLayout.LayoutParams.WRAP_CONTENT????
);????
//調(diào)用addView()方法增加一個TextView到線性布局中????
mLayout.addView(textView,?p);????
//比較簡單的一個例子

LayoutParams繼承于Android.View.ViewGroup.LayoutParams.
LayoutParams相當于一個Layout的信息包，它封裝了Layout的位置、高、寬等信息。假設(shè)在屏幕上一塊區(qū)域是由一個Layout占領(lǐng)的，如果將一個View添加到一個Layout中，最好告訴Layout用戶期望的布局方式，也就是將一個認可的layoutParams傳遞進去。
可以這樣去形容LayoutParams，在象棋的棋盤上，每個棋子都占據(jù)一個位置，也就是每個棋子都有一個位置的信息，如這個棋子在4行4列，這里的“4行4列”就是棋子的LayoutParams。

但LayoutParams類也只是簡單的描述了寬高，寬和高都可以設(shè)置成三種值：
1，一個確定的值；
2，F(xiàn)ILL_PARENT
3，WRAP_CONTENT

2、addRule() public class RelativeLayout extends ViewGroup

java.lang.Object ???? android.view.View ? ???? android.view.ViewGroup ? ? ???? android.widget.RelativeLayout java.lang.Object ???? android.view.View ? ???? android.view.ViewGroup ? ? ???? android.widget.RelativeLayout
void android.widget.RelativeLayout.LayoutParams.addRule(int verb,?int anchor)
public void addRule (int verb, int anchor) 設(shè)置控件的相對位置 Added in API level 1

Adds a layout rule to be interpreted by the RelativeLayout. Use this for verbs that take a target, such as a sibling (ALIGN_RIGHT) or a boolean value (VISIBLE).

ParametersOne of the verbs defined by RelativeLayout, such as ALIGN_WITH_PARENT_LEFT.The id of another view to use as an anchor, or a boolean value(represented asTRUE) for true or 0 for false). For verbs that don't refer to another sibling (for example, ALIGN_WITH_PARENT_BOTTOM) just use -1.

package?sunny.example.layoutparamstaddrule;

import?android.content.Context;
import?android.util.AttributeSet;
import?android.widget.Button;
import?android.widget.RelativeLayout;
import?android.widget.RelativeLayout.LayoutParams;
import?android.widget.TextView;

public??class?TestView?extends?RelativeLayout{
	
	private?LayoutParams?mLayoutParams_1,mLayoutParams_2;
	Button?mButton;
	TextView?mTextView;
	public?TestView(Context?context)?{
		super(context);
		//?TODO?Auto-generated?constructor?stub
		mButton?=?new?Button(context);
		mTextView?=?new?TextView(context);
		init();
		
	}
	public?TestView(Context?context,?AttributeSet?attrs)?{
		super(context,?attrs);
		//?TODO?Auto-generated?constructor?stub
		mButton?=?new?Button(context);
		mTextView?=?new?TextView(context);
		init();
	}
	public?TestView(Context?context,?AttributeSet?attrs,?int?defStyle)?{
		super(context,?attrs,?defStyle);
		//?TODO?Auto-generated?constructor?stub
		mButton?=?new?Button(context);
		mTextView?=?new?TextView(context);
		init();
	}
	
	public?void?init(){
		
		mLayoutParams_1?=?new?LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT);
		mLayoutParams_1.addRule(RelativeLayout.ALIGN_TOP);?
		addView(mButton,mLayoutParams_1);
		
		
		mLayoutParams_2?=?new?LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT);
		mLayoutParams_2.addRule(RelativeLayout.BELOW,?TRUE);
		mTextView.setText("Hey");
		addView(mTextView,mLayoutParams_2);
	}
}

Thanks to 泡在網(wǎng)上的日子