怎么在代码中设置RelativeLayout的宽高

　　LayoutParams params = new LayoutParams(width,height);
　　然后使用RelativeLayout relativeLayout.setLayoutparams(params);就可以在程序中控制RelativeLayout的宽和高了。
　　不过需要注意的是，LayouParams的导入包的问题，导入的时候会提示很多，一定要选择RelativeLayout.LayoutParams这个才正确，否则出现ClassCastExcetpion异常.

设置RelativeLayout的宽高：
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.grid_item);
relativeView=(RelativeLayout)findViewById(R.layout.grid_item);
new Handler().postDelayed(new Runnable(){
@Override
public void run(){
relativeView.setLayoutParams(new RelativeLayout.LayoutParams(100,200));
}
}, 1000); ///延时，或不可行
}
可行方法：
RelativeLayout.LayoutParams linearParams = (RelativeLayout.LayoutParams)mScrollView.getLayoutParams();
linearParams.height = middleHeight;
mScrollView.setLayoutParams(linearParams);
设置的控件RelativeLayout 中，如果是 LinerLayout,或者是FrameLayout，做相应改动即可！