Android：自定义View、Paint、Canvas、attrs、customview、path
第一种：oncreate里启动自定义view
Activity代码：
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
public class MainActivity extends Activity
{
/**
* 两种方法：
* 1.直接在layout里找到自定义控件
* 2.oncreate里启动自定义view
*/
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
//先new一个自定义view对象
VerticalTextView view = new VerticalTextView(this);
setContentView(view);
// setContentView(R.layout.activity_main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
View类代码：
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.View;
public class VerticalTextView extends View
{
//定义一个自定义角度的文本
private Paint mPaint;
public VerticalTextView(Context context)
{
super(context);
init();
}
private void init()
{
mPaint = new Paint();
mPaint.setColor(Color.BLUE);
mPaint.setTextSize(50);
mPaint.setAntiAlias(true);//设置抗锯齿
}
@Override
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.bg);
canvas.rotate(75);
// canvas.rotate(60,bitmap.getWidth()*2 , bitmap.getHeight()*2);
canvas.drawText("CanvasHello", 0, 0, mPaint);
canvas.drawBitmap(bitmap, 0, 0, mPaint);
}
}
第二种：直接在layout里找到自定义控件(直接新建custom view)
1.新建attrs文件，增加自定义属性:
增加属性内容：
<declare-styleable name="LabelView"> <attr name="text" format="string" /> <attr name="textColor" format="color" /> <attr name="textSize" format="dimension" /> </declare-styleable>
或者：
<declare-styleable name="DraggableDot">
<attr name="radius" format="dimension" />
<attr name="legend" format="string" />
<attr name="anr">
<enum name="none" value="0" />
<enum name="thumbnail" value="1" />
<enum name="drop" value="2" />
</attr>
</declare-styleable>
范例：
<resources>
<declare-styleable name="MyView">
<attr name="mytext" format="string" />
<attr name="mytextColor" format="color" />
<attr name="mytextSize" format="dimension" />
</declare-styleable>
</resources>
2.增加自己的命名空间，将android修改为自己的包名：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:MyView="http://schemas.android.com/apk/res/com.example.aexh23_paint_canvas"
3.在layout中创建自定义view，设置自定义属性（控件包名记得修改）：
<com.example.aexh23_paint_canvas.VerticalTextView android:id="@+id/verticalTextView1" android:layout_width="wrap_content" android:layout_height="wrap_content" MyView:mytext="HelloWorld" MyView:mytextColor="#654321" MyView:mytextSize="35sp" android:layout_centerHorizontal="true" android:layout_centerVertical="true" />
范例：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:MyView="http://schemas.android.com/apk/res/com.example.aexh23_paint_canvas"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<com.example.aexh23_paint_canvas.VerticalTextView
android:id="@+id/verticalTextView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
MyView:mytext="HelloWorld"
MyView:mytextColor="#654321"
MyView:mytextSize="35sp"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true" />
</RelativeLayout>
4.在自定义view类中增加方法:
setTextColor(a.getColor(R.styleable.LabelView_textColor, 0xFF000000));
int textSize = a.getDimensionPixelOffset(R.styleable.LabelView_textSize, 0);
if (textSize > 0) {
setTextSize(textSize);
}
范例：
public class VerticalTextView extends View
{
/**
* 系统范例：LabelView
* 1.新建attrs文件，增加属性:
<declare-styleable name="LabelView">
<attr name="text" format="string" />
<attr name="textColor" format="color" />
<attr name="textSize" format="dimension" />
</declare-styleable>
//////////////////////////////////////////////
<declare-styleable name="DraggableDot">
<attr name="radius" format="dimension" />
<attr name="legend" format="string" />
<attr name="anr">
<enum name="none" value="0" />
<enum name="thumbnail" value="1" />
<enum name="drop" value="2" />
</attr>
</declare-styleable>
////////////////////////////////////////////////
2.增加自己的命名空间，将android修改为自己的包名
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:MyView="http://schemas.android.com/apk/res/com.example.aexh23_paint_canvas"
3.在layout中创建自定义view，增加属性
<com.example.aexh23_paint_canvas.VerticalTextView
android:id="@+id/verticalTextView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
MyView:mytext="HelloWorld"
MyView:mytextColor="#654321"
MyView:mytextSize="35sp"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true" />
4.在自定义view类中增加方法
setTextColor(a.getColor(R.styleable.LabelView_textColor, 0xFF000000));
int textSize = a.getDimensionPixelOffset(R.styleable.LabelView_textSize, 0);
if (textSize > 0) {
setTextSize(textSize);
}
*/
private Paint mPaint;
private CharSequence s;
private int c;
private int d;
public VerticalTextView(Context context, AttributeSet attrs)
{
super(context, attrs);
TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.MyView);
s = a.getString(R.styleable.MyView_mytext);
c = a.getColor(R.styleable.MyView_mytextColor, 0xFF000000);
d = a.getDimensionPixelOffset(R.styleable.MyView_mytextSize, 0);
init();
a.recycle();
}
//定义画笔
private void init()
{
mPaint = new Paint();
mPaint.setColor(c );
mPaint.setTextSize(d);
mPaint.setAntiAlias(true);// 设置抗锯齿
}
@Override
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.bg);
canvas.rotate(30);
// canvas.rotate(60,bitmap.getWidth()*2 , bitmap.getHeight()*2);
canvas.drawText(s.toString(), 0, 0, mPaint);
canvas.drawBitmap(bitmap, 0, 0, mPaint);
}
}
参考资料：
Android画图Path的使用（paint）
http://www.cnblogs.com/tt_mc/archive/2012/12/07/2807518.html
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