Android布局小結

1.FrameLayout

幀布局，效果為多個圖層依次疊加，比如說畫一幅畫，在FrameLayout中先添加背景imageView，再添加其他的事物imageView即可。

如何實現三個按鈕在水平方向上左對齊、居中對其和右對齊？

在FrameLayout中可對每個View設置Layout_gravity屬性實現

code：

<frameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/linearLayout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    tools:context=".MainActivity" >

    
    
     
     
      
    
</frameLayout>

2.LinearLayout布局<喎?/kf/ware/vc/" target="_blank" class="keylink">vcD4KPHA+1NpMaW5lYXJMYXlvdXTW0MztvNO31r3nz9+jujwvcD4KPHA+zai5/cno1sNhbmRyb2lkOlNob3dEaXZpZGVyc8r00NQobm9uZS9iZWdpbm5pbmcvZW5kL21pZGRsZSm6zWFuZHJvaWQ6ZHJpdmlkZXLK9NDUKERyYXdhYmxlIElEKTwvcD4KPHA+yOe6ztTaTGluZWFyTGF5b3V01tDKtc/WyP249rC0xaXLrsa9t73P8rfWsfC+09Pa1/PW0NPSzrvWw6O/PC9wPgo8cD7J6NbDQnV0dG9utcRsYXlvdXRfd2VpZ2h0yvTQ1Ly0v8k8L3A+CjxwPjMuUmVsYXRpdmVMYXlvdXSyvL7WPC9wPgo8cD7Ktc/WNbj2sLTFpcO3u6jXtMXF0PKhozwvcD4KPHA+0Ke5+828o7o8L3A+CjxwPjxpbWcgc3JjPQ=="/uploadfile/Collfiles/20141224/2014122409110324.jpg" alt="\">

code：

通過LayoutParams實現。

code：

btn = (Button) findViewById(R.id.btn1);
		btn.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
						ViewGroup.LayoutParams.WRAP_CONTENT,
						ViewGroup.LayoutParams.WRAP_CONTENT);
				if(i == 1){
					i = 0;
					lp.addRule(RelativeLayout.CENTER_IN_PARENT,RelativeLayout.TRUE);
				}
				else{
					i = 1;
					lp.addRule(RelativeLayout.ALIGN_PARENT_TOP,RelativeLayout.TRUE);
				}
				btn.setLayoutParams(lp);
			}
		});

GradientDrawable，通過向函數傳入漸變方向及顏色數組設置背景漸變情況

code：

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		int[] col = {Color.BLUE,Color.BLACK};
		GradientDrawable gd = new GradientDrawable(Orientation.TOP_BOTTOM, col);
		getWindow().setBackgroundDrawable(gd);
	}