今天自定义了一个button按钮,需要添加一个属性,具体步骤如下
1.新属性的信息设定:在values目录下添加attrs.xml文件,在里面添加属性信息
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="ColorButton">
<attr name="textNumber" format="reference|string" />
</declare-styleable>
</resources>
2.在xml中添加
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:myattr="http://schemas.android.com/apk/res/com.android.calculator2" android:id="@+id/simplePad" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center" android:divider="@drawable/horizontal_line" android:orientation="vertical" android:showDividers="middle" > <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:divider="@drawable/vertical_line" android:showDividers="middle" > <com.android.calculator2.ColorButton android:id="@+id/cle" style="@style/simple_button_style" /> <com.android.calculator2.ColorButton android:id="@+id/del" style="@style/simple_button_style" /> <com.android.calculator2.ColorButton android:id="@+id/div" style="@style/simple_button_style" myattr:textNumber="@string/div" /> <com.android.calculator2.ColorButton android:id="@+id/mul" style="@style/simple_button_style" android:contentDescription="@string/divDesc" myattr:textNumber="@string/mul" /> </LinearLayout> </LinearLayout>
这里有一点要注意,就是必须添加一条语句xmlns:myattr="http://schemas.android.com/apk/res/com.android.calculator2" 格式为xmlns:自己起个名字=“//schemas.android.com/apk/res/自己应用的包名”这个名字你会发现他的用处,就是在引用这个资源的时候,添加了一个区域前缀,就像android:text 自定义的使用就是myattr:textNumber
3.在代码中的引用
代码如下
package com.android.calculator2; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Paint; import android.graphics.drawable.Drawable; import android.graphics.drawable.StateListDrawable; import android.util.AttributeSet; import android.view.View.OnClickListener; import android.view.View; import android.widget.Button; class ColorButton extends Button implements OnClickListener { int CLICK_FEEDBACK_COLOR; static final int CLICK_FEEDBACK_INTERVAL = 10; static final int CLICK_FEEDBACK_DURATION = 350; private String mText; float mTextX; float mTextY; long mAnimStart; OnClickListener mListener; public ColorButton(Context context, AttributeSet attrs) { super(context, attrs); Calculator calc = (Calculator) context; mListener = calc.mListener; setOnClickListener(this); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.ColorButton); int resourceId = a.getResourceId(R.styleable.ColorButton_textNumber, 0); mText = resourceId < 0 ? "" : a.getString(R.styleable.ColorButton_textNumber); a.recycle(); } public void onClick(View view) { mListener.onClick(this); } @Override public void onSizeChanged(int w, int h, int oldW, int oldH) { measureText(); } private void measureText() { Paint paint = getPaint(); mTextX = (getWidth() - paint.measureText(getText().toString())) / 2; mTextY = (getHeight() - paint.ascent() - paint.descent()) / 2; } @Override protected void onTextChanged(CharSequence text, int start, int before, int after) { measureText(); }
//添加图片背景
public StateListDrawable setbg(TypedArray normal, TypedArray prossed, int drawableId) { StateListDrawable bg = new StateListDrawable(); Drawable normal_state = normal.getDrawable(drawableId); Drawable pressed_state = prossed.getDrawable(drawableId); bg.addState(new int[] { android.R.attr.state_pressed }, pressed_state); bg.addState(new int[] { -android.R.attr.state_pressed }, normal_state); return bg; } public String getTextNumber() { return mText; } }
注意:int resourceId = a.getResourceId(R.styleable.ColorButton_textNumber, 0)的时候,必须是attrs 中declare-styleable的名字+下划线+属性名
对这个类的引用的地方如下
TypedArray simpleButtons = res.obtainTypedArray(R.array.simple_buttons_id); TypedArray advanceButtons = res.obtainTypedArray(R.array.advance_buttons_id); TypedArray imagesAdvanceNormal = res.obtainTypedArray(R.array.advance_drawable_normal); TypedArray imagesAdvancePressed = res.obtainTypedArray(R.array.advance_drawable_pressed); TypedArray imagesSimpleNormal = res.obtainTypedArray(R.array.simple_drawable_normal); TypedArray imagesSimplePressed = res.obtainTypedArray(R.array.simple_drawable_pressed); for (int i = 0; i < simpleButtons.length(); i++) { final ColorButton button = (ColorButton) simplePage.findViewById(simpleButtons .getResourceId(i, 0)); StateListDrawable drawable = button.setbg(imagesSimpleNormal, imagesSimplePressed, i); button.setBackgroundDrawable(drawable); } for (int i = 0; i < advanceButtons.length(); i++) { final ColorButton button = (ColorButton) advancedPage.findViewById( advanceButtons.getResourceId(i, 0)); StateListDrawable drawable = button.setbg(imagesAdvanceNormal, imagesAdvancePressed, i); button.setBackgroundDrawable(drawable); } imagesSimpleNormal.recycle(); imagesSimplePressed.recycle(); imagesAdvanceNormal.recycle(); imagesAdvancePressed.recycle();
补充:
对于format属性
如下
<!--reference:参考某一资源ID--> <!--属性定义--> <declare-styleable name="名称"> <attr format="reference" name="background" /> </declare-styleable> <!--属性使用--> <ImageView android:layout_width="42dip" android:layout_height="42dip" android:background="@drawable/图片ID" /> <!--color:颜色值--> <!--属性定义--> <declare-styleable name="名称"> <attr format="color" name="textColor" /> </declare-styleable> <!--属性使用--> <TextView android:layout_width="42dip" android:layout_height="42dip" android:textColor="#00FF00" /> <!--boolean:布尔值--> <!--属性定义--> <declare-styleable name="名称"> <attr format="boolean" name="focusable" /> </declare-styleable> <!--属性使用--> <Button android:layout_width="42dip" android:layout_height="42dip" android:focusable="true" /> <!--dimension:尺寸值--> <!--属性定义--> <declare-styleable name="名称"> <attr format="dimension" name="layout_width" /> </declare-styleable> <!--属性使用--> <Button android:layout_width="42dip" android:layout_height="42dip" /> <!--float:浮点值--> <!--属性定义--> <declare-styleable name="AlphaAnimation"> <attr format="float" name="fromAlpha" /> <attr format="float" name="toAlpha" /> </declare-styleable> <!--属性使用--> <alpha android:fromAlpha="1.0" android:toAlpha="0.7" /> <!--integer:整型值--> <!--属性定义--> <declare-styleable name="AnimatedRotateDrawable"> <attr format="integer" name="frameDuration" /> <attr format="integer" name="framesCount" /> </declare-styleable> <!--属性使用--> <animated-rotate android:frameDuration="100" android:framesCount="12" /> <!--string:字符串--> <!--属性定义--> <declare-styleable name="MapView"> <attr format="string" name="apiKey" /> </declare-styleable> <!--属性使用--> <com.google.android.maps.MapView android:layout_width="fill_parent" android:layout_height="fill_parent" android:apiKey="0jOkQ80oD1JL9C6HAja99uGXCRiS2CGjKO_bc_g" /> <!--fraction:百分数--> <!--属性定义--> <declare-styleable name="RotateDrawable"> <attr format="fraction" name="pivotX" /> <attr format="fraction" name="pivotY" /> </declare-styleable> <!--属性使用--> <rotate android:pivotX="200%" android:pivotY="300%" /> <!--enum:枚举值--> <!--属性定义--> <declare-styleable name="名称"> <attr name="orientation"> <enum name="horizontal" value="0" /> <enum name="vertical" value="1" /> </attr> </declare-styleable> <!--属性使用--> <LinearLayout android:orientation="vertical" > </LinearLayout> <!--flag:位或运算--> <!--属性定义--> <declare-styleable name="名称"> <attr name="windowSoftInputMode"> <flag name="stateUnspecified" value="0" /> <flag name="stateUnchanged" value="1" /> <flag name="stateHidden" value="2" /> <flag name="stateAlwaysHidden" value="3" /> <flag name="stateVisible" value="4" /> <flag name="stateAlwaysVisible" value="5" /> <flag name="adjustUnspecified" value="0x00" /> <flag name="adjustResize" value="0x10" /> <flag name="adjustPan" value="0x20" /> <flag name="adjustNothing" value="0x30" /> </attr> </declare-styleable> <!--属性使用--> <activity android:windowSoftInputMode="stateUnspecified | stateUnchanged | stateHidden" > </activity> <!--注意:属性定义时可以指定多种类型值--> <declare-styleable name="名称"> <attr format="reference|color" name="background" /> </declare-styleable> <ImageView android:layout_width="42dip" android:layout_height="42dip" android:background="@drawable/图片ID|#00FF00" />