LayoutParams使用示例

MainActivity如下:

package cc.c;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout.LayoutParams;
/**
 * Demo描述:
 * LayoutParams使用示例
 * 利用getLayoutParams()和setLayoutParams()获取和设置控件的布局
 */
public class MainActivity extends Activity {
	private Button mFirstButton;
	private Button mSecondButton;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        init();
    }
    private void init(){
    	mFirstButton=(Button) findViewById(R.id.firstButton);
    	mSecondButton=(Button) findViewById(R.id.secondButton);
    	mFirstButton.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				//1 获取到LayoutParams
				LayoutParams layoutParams= (LayoutParams) mSecondButton.getLayoutParams();
				//2 修改LayoutParams
				layoutParams.width=300;
				layoutParams.height=100;
				layoutParams.leftMargin=150;
				layoutParams.topMargin=300;
				//3 重新设置LayoutParams
				mSecondButton.setLayoutParams(layoutParams);
			}
		});

    }
}

main.xml如下:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
 <Button
        android:id="@+id/firstButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="firstButton" />

   <Button
        android:id="@+id/secondButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="100dip"
        android:text="secondButton" />

</LinearLayout>