Android 中自定義View的應(yīng)用

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android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="@string/hello"

/>

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="@string/hello"

/>

當(dāng)然上面的布局方式可以幫助我們完成簡(jiǎn)單應(yīng)用的開(kāi)發(fā)了，但是如果你想寫(xiě)一個(gè)復(fù)雜的應(yīng)用，這樣就有點(diǎn)牽強(qiáng)了，大家不信可以下源碼都研究看看，高手寫(xiě)的布局方式，如上面的布局高手通常是這樣寫(xiě)的:

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其中A extends LinerLayout, B extends TextView.

其中A extends LinerLayout, B extends TextView.

為了幫助大家更容易理解，我寫(xiě)了一個(gè)簡(jiǎn)單的Demo ,具體步驟如下：

首先新建一個(gè)Android 工程 命名為ViewDemo .

然后自定義一個(gè)View 類(lèi)，命名為MyView(extends View) .代碼如下:

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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();

//設(shè)置畫(huà)筆顏色

mPaint.setColor(Color.RED);

//設(shè)置填充

mPaint.setStyle(Style.FILL);

//畫(huà)一個(gè)矩形,前倆個(gè)是矩形左上角坐標(biāo)，后面?zhèn)z個(gè)是右下角坐標(biāo)

canvas.drawRect(new Rect(10, 10, 100, 100), mPaint);

mPaint.setColor(Color.BLUE);

//繪制文字

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();

//設(shè)置畫(huà)筆顏色

mPaint.setColor(Color.RED);

//設(shè)置填充

mPaint.setStyle(Style.FILL);

//畫(huà)一個(gè)矩形,前倆個(gè)是矩形左上角坐標(biāo)，后面?zhèn)z個(gè)是右下角坐標(biāo)

canvas.drawRect(new Rect(10, 10, 100, 100), mPaint);

mPaint.setColor(Color.BLUE);

//繪制文字

canvas.drawText(mString, 10, 110, mPaint);

}

}

然后將我們自定義的View 加入到main.xml 布局文件中,代碼如下:

view plaincopy to clipboardprint?

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="@string/hello"

/>

android:layout_width="fill_parent"

android:layout_height="fill_parent"

/>

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="@string/hello"

/>

android:layout_width="fill_parent"

android:layout_height="fill_parent"

/>