Android高手进阶教程(三)之----Android 中自定义View的应用.

大家好我们今天的教程是在Android 教程中自定义View 的学习，对于初学着来说，他们习惯了Android 传统的页面布局方式，如下代码:

[java]
view plaincopyprint?

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>
<TextView
android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="@string/hello"

/>
</LinearLayout>

[java]
view plaincopyprint?

<?xml version="1.0" encoding="utf-8"?>

<A>
<B></B>
</A>

<?xml version="1.0" encoding="utf-8"?>
<A>
<B></B>
</A>

[java]
view plaincopyprint?

其中A extends LinerLayout, B
extends TextView.

[java]
view plaincopyprint?

package com.android.tutor;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Rect;

import android.graphics.Paint.Style;

import android.util.AttributeSet;

import android.view.View;

public class MyView
extends View {
private Paint mPaint;

private Context mContext;

private static
final String mString = "Welcome to Mr Wei's blog";

public MyView(Context context) {

super(context);

}
public MyView(Context context,AttributeSet attr)

{
super(context,attr);

}
@Override
protected
void onDraw(Canvas canvas) {
// TODO Auto-generated method stub

super.onDraw(canvas);

mPaint = new Paint();

//设置画笔颜色
mPaint.setColor(Color.RED);
//设置填充
mPaint.setStyle(Style.FILL);

//画一个矩形,前俩个是矩形左上角坐标，后面俩个是右下角坐标
canvas.drawRect(new Rect(10,
10, 100,
100), mPaint);

mPaint.setColor(Color.BLUE);
//绘制文字
canvas.drawText(mString, 10,
110, mPaint);
}
}

package com.android.tutor;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Paint.Style;
import android.util.AttributeSet;
import android.view.View;
public class MyView extends View {
private Paint mPaint;
private Context mContext;
private static final String mString = "Welcome to Mr Wei's blog";

public MyView(Context context) {
super(context);

}
public MyView(Context context,AttributeSet attr)
{
super(context,attr);

}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);

mPaint = new Paint();

//设置画笔颜色
mPaint.setColor(Color.RED);
//设置填充
mPaint.setStyle(Style.FILL);

//画一个矩形,前俩个是矩形左上角坐标，后面俩个是右下角坐标
canvas.drawRect(new Rect(10, 10, 100, 100), mPaint);

mPaint.setColor(Color.BLUE);
//绘制文字
canvas.drawText(mString, 10, 110, mPaint);
}
}

然后将我们自定义的View 加入到main.xml 布局文件中,代码如下:

[java]
view plaincopyprint?

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>
<TextView
android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="@string/hello"

/>
<com.android.tutor.MyView
android:layout_width="fill_parent"

android:layout_height="fill_parent"

/>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
<com.android.tutor.MyView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
</LinearLayout>

最后执行之，效果如下图: