常见Layout的LayoutParams总结

参考：
Android MarginLeft与MarginStart的区别
http://blog.youkuaiyun.com/zhufuing/article/details/40181815

常见Layout的LayoutParams总结

http://haking.iteye.com/blog/1182334

LayoutParams

// <-- android.view.ViewGroup.LayoutParams
public static class LayoutParams {
    public static final int MATCH_PARENT = -1;
    public static final int WRAP_CONTENT = -2;

    public int width;
    public int height;
}
// android:layout_height
// Specifies the basic height of the view.
// android:layout_width
// Specifies the basic width of the view.

MarginLayoutParams

//支持margin的View的布局，继承了LayoutParams
// <-- android.view.ViewGroup.LayoutParams
// <-- android.view.ViewGroup.MarginLayoutParams
public static class MarginLayoutParams extends ViewGroup.LayoutParams {
    public int leftMargin;
    public int topMargin;
    public int rightMargin;
    public int bottomMargin;
    //默认相当于leftMargin，用在RTL布局中
    private int startMargin = DEFAULT_MARGIN_RELATIVE;

    //默认相当于rightMargin，用在RTL布局中
    private int endMargin = DEFAULT_MARGIN_RELATIVE;
}
// android:layout_marginBottom
// Specifies extra space on the bottom side of this view.
// android:layout_marginLeft
// Specifies extra space on the left side of this view.
// android:layout_marginRight
// Specifies extra space on the right side of this view.
// android:layout_marginTop
// Specifies extra space on the top side of this view.

FrameLayout.LayoutParams

// <-- android.view.ViewGroup.LayoutParams
// <-- android.view.ViewGroup.MarginLayoutParams
// <-- android.widget.FrameLayout.LayoutParams
public static class LayoutParams extends MarginLayoutParams {
    public int gravity = UNSPECIFIED_GRAVITY;   //也就是Gravity.TOP | Gravity.START

    public LayoutParams(int width, int height, int gravity) {
        super(width, height);
        this.gravity = gravity;
    }
}
// android:layout_gravity            
// Standard gravity constant that a child can supply to its parent
// 注意区别android:gravity, 这个属性是android.view.Gravity,
// FrameLayout.LayoutParams, LinearLayout.LayoutParams和各种常见的View都有android:gravity ；注意RelativeLayout.LayoutParams没有这个属性。

LinearLayout.LayoutParams

// <-- android.view.ViewGroup.LayoutParams
// <-- android.view.ViewGroup.MarginLayoutParams
// <-- android.widget.LinearLayout.LayoutParams
public static class LayoutParams extends ViewGroup.MarginLayoutParams {
    //非0表示可以让View撑大
    public float weight;

    /**
     * Gravity for the view associated with these LayoutParams.
     *
     * @see android.view.Gravity
     */
    @ViewDebug.ExportedProperty(category = "layout", mapping = {
        @ViewDebug.IntToString(from =  -1,                       to = "NONE"),
        @ViewDebug.IntToString(from = Gravity.NO_GRAVITY,        to = "NONE"),
        @ViewDebug.IntToString(from = Gravity.TOP,               to = "TOP"),
        @ViewDebug.IntToString(from = Gravity.BOTTOM,            to = "BOTTOM"),
        @ViewDebug.IntToString(from = Gravity.LEFT,              to = "LEFT"),
        @ViewDebug.IntToString(from = Gravity.RIGHT,             to = "RIGHT"),
        @ViewDebug.IntToString(from = Gravity.START,            to = "START"),
        @ViewDebug.IntToString(from = Gravity.END,             to = "END"),
        @ViewDebug.IntToString(from = Gravity.CENTER_VERTICAL,   to = "CENTER_VERTICAL"),
        @ViewDebug.IntToString(from = Gravity.FILL_VERTICAL,     to = "FILL_VERTICAL"),
        @ViewDebug.IntToString(from = Gravity.CENTER_HORIZONTAL, to = "CENTER_HORIZONTAL"),
        @ViewDebug.IntToString(from = Gravity.FILL_HORIZONTAL,   to = "FILL_HORIZONTAL"),
        @ViewDebug.IntToString(from = Gravity.CENTER,            to = "CENTER"),
        @ViewDebug.IntToString(from = Gravity.FILL,              to = "FILL")
    })
    public int gravity = -1;

    public LayoutParams(int width, int height, float weight) {
        super(width, height);
        this.weight = weight;
    }
}
// android:layout_gravity          
// Standard gravity constant that a child can supply to its parent
// android:layout_weight      

RelativeLayout

// <-- android.view.ViewGroup.LayoutParams
// <-- android.view.ViewGroup.MarginLayoutParams
// <-- android.widget.RelativeLayout.LayoutParams
 
// android:layout_above                            
// Positions the bottom edge of this view above the given anchor view ID. 
// android:layout_alignBaseline                 
// Positions the baseline of this view on the baseline of the given anchor view ID. 
// android:layout_alignBottom                   
// Makes the bottom edge of this view match the bottom edge of the given anchor view ID. 
// android:layout_alignLeft                        
// Makes the left edge of this view match the left edge of the given anchor view ID. 
// android:layout_alignParentBottom          
// If true, makes the bottom edge of this view match the bottom edge of the parent. 
// android:layout_alignParentLeft               
// If true, makes the left edge of this view match the left edge of the parent. 
// android:layout_alignParentRight             
// If true, makes the right edge of this view match the right edge of the parent. 
// android:layout_alignParentTop               
// If true, makes the top edge of this view match the top edge of the parent. 
// android:layout_alignRight                       
// Makes the right edge of this view match the right edge of the given anchor view ID. 
// android:layout_alignTop                         
// Makes the top edge of this view match the top edge of the given anchor view ID. 
// android:layout_alignWithParentIfMissing      
// If set to true, the parent will be used as the anchor when the anchor cannot be be found for layout_toLeftOf, layout_toRightOf, etc. 
// android:layout_below                            
// Positions the top edge of this view below the given anchor view ID. 
// android:layout_centerHorizontal           
// If true, centers this child horizontally within its parent. 
// android:layout_centerInParent              
// If true, centers this child horizontally and vertically within its parent. 
// android:layout_centerVertical               
// If true, centers this child vertically within its parent. 
// android:layout_toLeftOf                         
// Positions the right edge of this view to the left of the given anchor view ID. 
// android:layout_toRightOf                      
// Positions the left edge of this view to the right of the given anchor view ID.

TableLayout
<-- android.view.ViewGroup.LayoutParams
<-- android.view.ViewGroup.MarginLayoutParams
<-- android.widget.LinearLayout.LayoutParams
<-- android.widget.TableLayout.LayoutParams