Android 中自定義View的應用

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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"

/>

當然上面的布局方式可以幫助我們完成簡單應用的開發了，但是如果你想寫一個復雜的應用，這樣就有點牽強了，大家不信可以下源碼都研究看看，高手寫的布局方式，如上面的布局高手通常是這樣寫的:

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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，我寫了一個簡單的Demo ,具體步驟如下：

首先新建一個Android 工程 命名為ViewDemo .

然后自定義一個View 類，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();

//設置畫筆顏色

mPaint.setColor(Color.RED);

//設置填充

mPaint.setStyle(Style.FILL);

//畫一個矩形,前倆個是矩形左上角坐標，后面倆個是右下角坐標

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();

//設置畫筆顏色

mPaint.setColor(Color.RED);

//設置填充

mPaint.setStyle(Style.FILL);

//畫一個矩形,前倆個是矩形左上角坐標，后面倆個是右下角坐標

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"

/>