使用LayoutParams设置布局
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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的一个内部类, 每个不同的ViewGroup都有自己的LayoutParams子类
DEMO:
//创建一个线性布局 private LinearLayout mLayout; mLayout = (LinearLayout) findViewById(R.id.layout); //现在要往mLayout里边添加一个TextView TextView textView = new TextView(Activity01.this); textView.setText("Text View " ); //这里是设置 这个textView的布局 FILL_PARENT WRAP_CONTENT 和在xml文件里边设置是一样的如 /***/ //第一个参数为宽的设置,第二个参数为高的设置。 LinearLayout.LayoutParams p = new LinearLayout.LayoutParams( LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT ); //调用addView()方法增加一个TextView到线性布局中 mLayout.addView(textView, p); //比较简单的一个例子
LayoutParams继承于Android.View.ViewGroup.LayoutParams.
LayoutParams相当于一个Layout的信息包,它封装了Layout的位置、高、宽等信息。假设在屏幕上一块区域是由一个Layout占领的,如果将一个View添加到一个Layout中,最好告诉Layout用户期望的布局方式,也就是将一个认可的layoutParams传递进去。
可以这样去形容LayoutParams,在象棋的棋盘上,每个棋子都占据一个位置,也就是每个棋子都有一个位置的信息,如这个棋子在4行4列,这里的“4行4列”就是棋子的LayoutParams。
但LayoutParams类也只是简单的描述了宽高,宽和高都可以设置成三种值:
1,一个确定的值;
2,FILL_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) 设置控件的相对位置
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 泡在网上的日子
verb | anchor |
---|