场景：经常在项目中高频使用按钮，比如 完成、下一步等有圆角且有按下效果的Button

思路：写个自定义Button，编写自定义属性，方便在xml中设置圆角，颜色等属性，按下的效果一般是用shape写背景方式完成，为了方便，shape不在xml编写，改为代码编写。

1.编写自定义控件：

public class ShapeButton extends AppCompatButton {

    public ShapeButton(Context context) {
        this(context, null);
    }

    public ShapeButton(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public ShapeButton(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

}

---

2.编写自定义属性：

<declare-styleable name="ShapeButton">
<!--按下的颜色-->
<attr name="pressed_color" format="color" />
<!--正常状态颜色-->
<attr name="normal_color" format="color" />
<!--不可用的颜色-->
<attr name="enabled_color" format="color" />
<!--按钮圆角半径-->
<attr name="radius_size" format="dimension" />
<!--gravity-->
<attr name="android:gravity" />
</declare-styleable>

---

3.读取自定义属性：

     private int normal_color;
     private int pressed_color;
     private int enabled_color;
     private int gravity;
     private int radius_size;

    public ShapeButton(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        TypedArray ta = getContext().obtainStyledAttributes(attrs, R.styleable.ShapeButton);
        normal_color = ta.getColor(R.styleable.ShapeButton_normal_color, Color.parseColor("#FF3333"));
        pressed_color = ta.getColor(R.styleable.ShapeButton_pressed_color, Color.parseColor("#CC3333"));
        enabled_color = ta.getColor(R.styleable.ShapeButton_enabled_color, Color.GRAY);
        radius_size = (int) ta.getDimension(R.styleable.ShapeButton_radius_size, dip2px(4));
        gravity = ta.getInt(R.styleable.ShapeButton_android_gravity, Gravity.CENTER);
        ta.recycle();
    }

---

4.为控件赋值：

     private void init() {
         setGravity(gravity);
         setBackgroundDrawable(getStateListDrawable(getSolidRectDrawable(radius_size, pressed_color), getSolidRectDrawable(radius_size, normal_color)));
     }

    /**
     * 得到实心的drawable, 一般作为选中，点中的效果
     *
     * @param cornerRadius 圆角半径
     * @param solidColor   实心颜色
     * @return 得到实心效果
     */
    public static GradientDrawable getSolidRectDrawable(int cornerRadius, int solidColor) {
        GradientDrawable gradientDrawable = new GradientDrawable();
        // 设置矩形的圆角半径
        gradientDrawable.setCornerRadius(cornerRadius);
        // 设置绘画图片色值
        gradientDrawable.setColor(solidColor);
        // 绘画的是矩形
        gradientDrawable.setGradientType(GradientDrawable.RADIAL_GRADIENT);
        return gradientDrawable;
    }

    /**
     * 背景选择器
     *
     * @param pressedDrawable 按下状态的Drawable
     * @param normalDrawable  正常状态的Drawable
     * @return 状态选择器
     */
    public StateListDrawable getStateListDrawable(Drawable pressedDrawable, Drawable normalDrawable) {
        StateListDrawable stateListDrawable = new StateListDrawable();
        stateListDrawable.addState(new int[]{android.R.attr.state_enabled, android.R.attr.state_pressed}, pressedDrawable);
        stateListDrawable.addState(new int[]{android.R.attr.state_enabled}, normalDrawable);
        //设置不能用的状态
        //默认其他状态背景
        GradientDrawable gray = getSolidRectDrawable(radius_size, enabled_color);
        stateListDrawable.addState(new int[]{}, gray);
        return stateListDrawable;
    }

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5.效果预览

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6.完整代码：

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.GradientDrawable;
import android.graphics.drawable.StateListDrawable;
import android.support.annotation.ColorInt;
import android.support.v7.widget.AppCompatButton;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;
import com.chao.baselib.R;
/**
* Created by Chao on 2017/8/24.
*/
public class ShapeButton extends AppCompatButton {
private int normal_color;
private int pressed_color;
private int enabled_color;
private int gravity;
private int radius_size;
public ShapeButton(Context context) {
this(context, null);
}
public ShapeButton(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public ShapeButton(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
TypedArray ta = getContext().obtainStyledAttributes(attrs, R.styleable.ShapeButton);
normal_color = ta.getColor(R.styleable.ShapeButton_normal_color, Color.parseColor("#FF3333"));
pressed_color = ta.getColor(R.styleable.ShapeButton_pressed_color, Color.parseColor("#CC3333"));
enabled_color = ta.getColor(R.styleable.ShapeButton_enabled_color, Color.GRAY);
radius_size = (int) ta.getDimension(R.styleable.ShapeButton_radius_size, dip2px(4));
gravity = ta.getInt(R.styleable.ShapeButton_android_gravity, Gravity.CENTER);
//        int textColor = attrs.getAttributeIntValue(
//                "http://schemas.android.com/apk/res/android", "textColor", Color.WHITE);
//        setTextColor(textColor);
ta.recycle();
TypedArray tar = getContext().obtainStyledAttributes(attrs, new int[]{android.R.attr.textColor, android.R.attr.paddingTop, android.R.attr.paddingBottom});
if (tar != null) {
setTextColor(tar.getColor(0, Color.WHITE));
setPadding(6, (int) tar.getDimension(1, 8), 6, (int) tar.getDimension(2, 8));
}
setGravity(gravity);
tar.recycle();
init();
}
@Override
public void setTextColor(@ColorInt int color) {
super.setTextColor(color);
}
private void init() {
setBackgroundDrawable(getStateListDrawable(getSolidRectDrawable(radius_size, pressed_color), getSolidRectDrawable(radius_size, normal_color)));
setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
}
});
}
@Override
public void setPadding(int left, int top, int right, int bottom) {
super.setPadding(dip2px(left), dip2px(top), dip2px(right), dip2px(bottom));
}
/**
* 得到实心的drawable, 一般作为选中，点中的效果
*
* @param cornerRadius 圆角半径
* @param solidColor   实心颜色
* @return 得到实心效果
*/
public static GradientDrawable getSolidRectDrawable(int cornerRadius, int solidColor) {
GradientDrawable gradientDrawable = new GradientDrawable();
// 设置矩形的圆角半径
gradientDrawable.setCornerRadius(cornerRadius);
// 设置绘画图片色值
gradientDrawable.setColor(solidColor);
// 绘画的是矩形
gradientDrawable.setGradientType(GradientDrawable.RADIAL_GRADIENT);
return gradientDrawable;
}
/**
* 背景选择器
*
* @param pressedDrawable 按下状态的Drawable
* @param normalDrawable  正常状态的Drawable
* @return 状态选择器
*/
public StateListDrawable getStateListDrawable(Drawable pressedDrawable, Drawable normalDrawable) {
StateListDrawable stateListDrawable = new StateListDrawable();
stateListDrawable.addState(new int[]{android.R.attr.state_enabled, android.R.attr.state_pressed}, pressedDrawable);
stateListDrawable.addState(new int[]{android.R.attr.state_enabled}, normalDrawable);
//设置不能用的状态
//默认其他状态背景
GradientDrawable gray = getSolidRectDrawable(radius_size, enabled_color);
stateListDrawable.addState(new int[]{}, gray);
return stateListDrawable;
}
private int dip2px(float dpValue) {
final float scale = getResources()
.getDisplayMetrics().density;
return (int) (dpValue * scale + 0.5f);
}
}