2023年7月15日发(作者：)

Android 2D 绘图--------Drawable类的用法

一． 从项目资源来创建图像

1. Java程序代码内使用方法建立窗体布局

代码：

public class MDrawableActivity extends Activity {

@Override

public void onCreate(Bundle savedInstanceState) {

te(savedInstanceState);

LinearLayout mLinearLayout = new

LinearLayout(this);

ImageView mImageView = new ImageView(this);

geResource(ua);

ustViewBounds(true);

outParams(new

Params(_CONTENT,

_CONTENT));

w(mImageView);

setContentView(mLinearLayout);

}

} 2. 通过Resources 类来获得项目资源

Resources res = getResources();

Drawable drawable = wable();

二． 从XML文件来定义图像

1) 可在XML文件定义的绘图子类

绘图子类 XML文件内的标签名称

AnimationDrawable(动画绘图)

BitmapDrawable(图像绘图)

ClipDrawble(剪切绘图)

ColorDrawable(色彩绘图)

GradientDrawable(斜度绘图)

InsetDrawable(插入绘图)

(层次绘图)

LevelListDrawable

RotateDrawable(旋转绘图)

ScaleDrawable(缩放绘图)

StateListDrawable

TransitionDrawable(过度绘图)

2)定义图像的xml文件（以TransitionDrawable为例）

xmlns:android=/apk/res/android>

代码：

public class TransitionDrawableActivity extends Activity

{

@Override

public void onCreate(Bundle savedInstanceState) {

te(savedInstanceState);

setContentView();

Resources res = getResources();

TransitionDrawable transition =

(TransitionDrawable)wable(tion_image); //图片自动从第一张慢慢淡化到第二张。

ImageView mImageView =

(ImageView)findViewById(View);

geDrawable(transition);

ransition(5*1000);

}

}

2) 自定义View对象

public class MShapeDrawable extends View {

private ShapeDrawable mShapDrawable;

public MShapeDrawable(Context context) {

super(context);

int x = 10;

int y = 10;

int width = 300;

int height = 50;

mShapDrawable = new ShapeDrawable(new OvalShape());

nt().setColor(0xff74AC23);

nds(x ,y , x+width, y+height);

}

protected void onDraw(Canvas canvas) {

(canvas);

}

}

然后在Activity里面显示

public class ShapDrawableActivity extends Activity {

@Override

public void onCreate(Bundle savedInstanceState){

te(savedInstanceState);

MShapeDrawable mShapDrawable = new

MShapeDrawable(this);

setContentView(mShapDrawable);

}

}