【移動應(yīng)用開發(fā)技術(shù)】Android中怎么實現(xiàn)畫圖

Android中怎么實現(xiàn)畫圖，針對這個問題，這篇文章詳細介紹了相對應(yīng)的分析和解答，希望可以幫助更多想解決這個問題的小伙伴找到更簡單易行的方法。在Android

操作系統(tǒng)開發(fā)中，對于圖形界面的操作時非常常見的一個基礎(chǔ)操作。我們可以先通過本文介紹的有關(guān)Android畫圖的相關(guān)操作，來具體了解一下圖形界面的操作技巧，以此提高我們對這一系統(tǒng)的認(rèn)知程度。import

java.io.InputStream;

import

android.app.Activity;

import

android.content.Context;

import

android.graphics.Bitmap;

import

android.graphics.BitmapFactory;

import

android.graphics.Canvas;

import

android.graphics.Color;

import

android.graphics.LinearGradient;

import

android.graphics.Paint;

import

android.graphics.PorterDuff;

import

android.graphics.PorterDuffXfermode;

import

android.graphics.Shader;

import

android.graphics.Typeface;

import

android.os.Bundle;

import

android.view.View;

public

class

AlphaBitmap

extends

Activity

{

@Override

protected

void

onCreate(Bundle

savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(new

SampleView(this));

}

private

static

class

SampleView

extends

View

{

private

Bitmap

mBitmap;

private

Bitmap

mBitmap2;

private

Bitmap

mBitmap3;

private

Shader

mShader;

private

static

void

drawIntoBitmap(Bitmap

bm)

{

float

x

=

bm.getWidth();

float

y

=

bm.getHeight();

//

建一個有制定對象的畫布

Canvas

c

=

new

Canvas(bm);

Paint

p

=

new

Paint();

//

主要用來消除邊緣吧從效果上看

好像false的話有毛邊

p.setAntiAlias(true);

p.setAlpha(0x555555);//灰色

c.drawCircle(x/2,

y/2,

x/2,

p);

p.setAlpha(0x0000ff);//藍色

p.setXfermode(new

PorterDuffXfermode(PorterDuff.Mode.SRC_OVER));

//

下面是字體的相關(guān)設(shè)置

p.setTextSize(20);

String

familyName

=

"宋體";

Typeface

font

=

Typeface.create(familyName,Typeface.ITALIC);

p.setTypeface(font);

p.setTextAlign(Paint.Align.CENTER);

Paint.FontMetrics

fm

=

p.getFontMetrics();

c.drawText("我愛android",

x/2,

(y-fm.ascent)/2,

p);

}

public

SampleView(Context

context)

{

super(context);

setFocusable(true);

//

得到圖像的幾種方法

InputStream

is

=

context.getResources().openRawResource(R.drawable.app_sample_code);

mBitmap

=

BitmapFactory.decodeStream(is);

//從一幅圖像抽取色值變?yōu)樾碌膱D像，一般是畫筆的顏色

同下面

p.setColor(Color.BLUE);

mBitmapmBitmap2

=

mBitmap.extractAlpha();

mBitmap3

=

Bitmap.createBitmap(200,

200,

Bitmap.Config.ALPHA_8);

drawIntoBitmap(mBitmap3);

//一種漸變效果

mShader

=

new

LinearGradient(0,

0,

150,

70,

new

int[]

{

Color.RED,

Color.GREEN,

Color.BLUE

},

null,

Shader.TileMode.MIRROR);

}

@Override

protected

void

onDraw(Canvas

canvas)

{

canvas.drawColor(Color.LTGRAY);

Paint

p

=

new

Paint();

float

y

=

10;

p.setColor(Color.BLUE);

canvas.drawBitmap(mBitmap,

10,

y,

p);

y

+=

mBitmap.getHeight()

+

10;

canvas.drawBitmap(mBitmap2,

10,

y,

p);

y

+=

mBitmap2.getHeight()

+

10;

p.setShader(mShader);

canvas.drawBitmap(mBitmap3,

10,

y,

p);

}

}

}

import

java.io.InputStream;

import

android.app.Activity;

import

android.content.Context;

import

android.graphics.Bitmap;

import

android.graphics.BitmapFactory;

import

android.graphics.Canvas;

import

android.graphics.Color;

import

android.graphics.LinearGradient;

import

android.graphics.Paint;

import

android.graphics.PorterDuff;

import

android.graphics.PorterDuffXfermode;

import

android.graphics.Shader;

import

android.graphics.Typeface;

import

android.os.Bundle;

import

android.view.View;

public

class

AlphaBitmap

extends

Activity

{

@Override

protected

void

onCreate(Bundle

savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(new

SampleView(this));

}

private

static

class

SampleView

extends

View

{

private

Bitmap

mBitmap;

private

Bitmap

mBitmap2;

private

Bitmap

mBitmap3;

private

Shader

mShader;

private

static

void

drawIntoBitmap(Bitmap

bm)

{

float

x

=

bm.getWidth();

float

y

=

bm.getHeight();

//

建一個有制定對象的畫布

Canvas

c

=

new

Canvas(bm);

Paint

p

=

new

Paint();

//

主要用來消除邊緣吧從效果上看

好像false的話有毛邊

p.setAntiAlias(true);

p.setAlpha(0x555555);//灰色

c.drawCircle(x/2,

y/2,

x/2,

p);

p.setAlpha(0x0000ff);//藍色

p.setXfermode(new

PorterDuffXfermode(PorterDuff.Mode.SRC_OVER));

//

下面是字體的相關(guān)設(shè)置

p.setTextSize(20);

String

familyName

=

"宋體";

Typeface

font

=

Typeface.create(familyName,Typeface.ITALIC);

p.setTypeface(font);

p.setTextAlign(Paint.Align.CENTER);

Paint.FontMetrics

fm

=

p.getFontMetrics();

c.drawText("我愛android",

x/2,

(y-fm.ascent)/2,

p);

}

public

SampleView(Context

context)

{

super(context);

setFocusable(true);

//

得到圖像的幾種方法

InputStream

is

=

context.getResources().openRawResource(R.drawable.app_sample_code);

mBitmap

=

BitmapFactory.decodeStream(is);

//從一幅圖像抽取色值變?yōu)樾碌膱D像，一般是畫筆的顏色

同下面

p.setColor(Color.BLUE);

mBitmapmBitmap2

=

mBitmap.extractAlpha();

mBitmap3

=

Bitmap.createBitmap(200,

200,

Bitmap.Config.ALPHA_8);

drawIntoBitmap(mBitmap3);

//一種漸變效果

mShader

=

new

LinearGradient(0,

0,

150,

70,

new

int[]

{

Color.RED,

Color.GREEN,

Color.BLUE

},

null,

Shader.TileMode.MIRROR);

}

@Override

protected

void

onDraw(Canvas

canvas)

{

canvas.drawColor(Color.LTGRAY);

Paint

p

=

new

Paint();

float