主要用來(lái)動(dòng)態(tài)控制子view的擺放位置

        TextView textView = new TextView(context);
        ViewGroup.LayoutParams layoutParams = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 200);
        layoutParams.width=100;
        layoutParams.height=200;
        textView.setLayoutParams(layoutParams);

構(gòu)造函數(shù)可是設(shè)置三種參數(shù)

• 固定數(shù)值，單位px
• ViewGroup.LayoutParams.MATCH_PARENT ，意思為寬度和父view相同
• ViewGroup.LayoutParams.WRAP_CONTENT，意思為自適應(yīng)

注意每個(gè)view所能獲得的layoutparams都是他所對(duì)應(yīng)的父view

比如textview外層包裹著的是一個(gè)linearlayout，那么

        LinearLayout.LayoutParams layoutParams1 = (LinearLayout.LayoutParams) textView.getLayoutParams();
        
        //設(shè)置權(quán)重比例
        layoutParams1.weight=1;
        
        //設(shè)置上部間距
        layoutParams1.topMargin=5;
        
        //設(shè)置右邊間距
        layoutParams1.setMarginEnd(20);
        
        //設(shè)置四周間距
        layoutParams1.setMargins(3,3,3,3);

如果是RelativeLayout：

        RelativeLayout.LayoutParams layoutParams1 = (RelativeLayout.LayoutParams) textView.getLayoutParams();

        //設(shè)置位置居中
        layoutParams1.addRule(RelativeLayout.CENTER_IN_PARENT);
        
        //設(shè)置在某一個(gè)id所對(duì)應(yīng)的view的右邊
        layoutParams1.addRule(RelativeLayout.RIGHT_OF, R.id.all);
        
        layoutParams1.topMargin=5;
        layoutParams1.setMarginEnd(20);
        layoutParams1.setMargins(3,3,3,3);
        
        layoutParams1.removeRule(RelativeLayout.CENTER_IN_PARENT);

如果是FrameLayout:

        FrameLayout.LayoutParams layoutParams1 = (FrameLayout.LayoutParams) textView.getLayoutParams();
        
        //設(shè)置位置居中
        layoutParams1.gravity = Gravity.CENTER;

        layoutParams1.topMargin = 5;
        layoutParams1.setMarginEnd(20);
        layoutParams1.setMargins(3, 3, 3, 3);