Android:如何为LinearLayout绘制边框
Android:如何为LinearLayout绘制边框
提问于 2011-11-21 02:17:26
我有三个文件。XML、绘图函数和主要活动。我的XML文件中有一些LinearLayout。
<LinearLayout android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1">
<LinearLayout android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#ef3"
android:id="@+id/img01"/>
<LinearLayout android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
android:background="#E8A2B4"
android:id="@+id/img02"/>
</LinearLayout>这是绘图函数：
public class getBorder extends TextView {
public getBorder(Context context) {
super(context);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Paint paint = new Paint();
paint.setColor(android.graphics.Color.RED);
canvas.drawLine(0, 0, this.getWidth() - 1, 0, paint);
canvas.drawLine(0, 0, 0, this.getHeight() - 1, paint);
canvas.drawLine(this.getWidth() - 1, 0, this.getWidth() - 1,
this.getHeight() - 1, paint);
canvas.drawLine(0, this.getHeight() - 1, this.getWidth() - 1,
this.getHeight() - 1, paint);
}
}这是主要的活动：
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final getBorder getBorder = new getBorder(this);
final LinearLayout img01 = (LinearLayout) findViewById(R.id.img01);
img01.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
getBorder.setWidth(100);
getBorder.setHeight(100);
img01.addView(getBorder);
}
});
}程序可以绘制边框，但大小不适合LinearLayout。当我再次点击LinearLayout时，程序崩溃了。
另外，我想在LinearLayout的中心画两个圆，但是如何计算出中心坐标呢？
回答 1
Stack Overflow用户
发布于 2012-06-28 19:37:19
扩展LinearLayout/RelativeLayout并直接在XML上使用它
package com.pkg_name ;
...imports...
public class LinearLayoutOutlined extends LinearLayout {
Paint paint;
public LinearLayoutOutlined(Context context) {
super(context);
// TODO Auto-generated constructor stub
setWillNotDraw(false) ;
paint = new Paint();
}
public LinearLayoutOutlined(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
setWillNotDraw(false) ;
paint = new Paint();
}
@Override
protected void onDraw(Canvas canvas) {
/*
Paint fillPaint = paint;
fillPaint.setARGB(255, 0, 255, 0);
fillPaint.setStyle(Paint.Style.FILL);
canvas.drawPaint(fillPaint) ;
*/
Paint strokePaint = paint;
strokePaint.setARGB(255, 255, 0, 0);
strokePaint.setStyle(Paint.Style.STROKE);
strokePaint.setStrokeWidth(2);
Rect r = canvas.getClipBounds() ;
Rect outline = new Rect( 1,1,r.right-1, r.bottom-1) ;
canvas.drawRect(outline, strokePaint) ;
}
}<?xml version="1.0" encoding="utf-8"?>
<com.pkg_name.LinearLayoutOutlined
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width=...
android:layout_height=...
>
... your widgets here ...
</com.pkg_name.LinearLayoutOutlined>页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/8203606
复制相关文章
相似问题