简介
日常项目开发中，经常会遇到把TextView设置成一个按钮，就像下面这个:
按钮.png
而一般的实现方式就是在res/drawable目录下定义一个drawable.xml文件:
然后设置为TextView的背景，如果需要选中时改变状态，可以这么设置：
这样写的好处是简单易懂，但是如果项目中用到了很多不同风格的边框背景时，就会创建非常多的相似的资源文件，比较麻烦。为了避免这种麻烦，这里使用Java代码来创建Drawable。
状态说明.png
自定义ShapeTextView
使用自定义view继承TextView来实现上面说的效果
定义属性
在res/values/attrs.xml中添加自定义属性
自定义View继承TextView
/**
* @author Lin
* @date 2019/8/22
* @description 实现自定义圆角背景
* 支持
* 1.四边圆角
* 2.指定边圆角
* 3.支持填充色以及边框色,边框虚线
* 4.支持按下效果
*/
@SuppressLint("AppCompatCustomView")
public class ShapeTextView extends TextView {
private boolean openSelector;
//自定背景边框Drawable
private GradientDrawable gradientDrawable;
//按下时的Drawable
private GradientDrawable selectorDrawable;
//填充色
private int solidColor = 0;
//边框色
private int strokeColor = 0;
//按下填充色
private int solidTouchColor = 0;
//按下边框色
private int strokeTouchColor = 0;
//按下字体色
private int textTouchColor = 0;
//边框宽度
private int strokeWidth = 0;
//四个角的弧度
private float radius;
private float topLeftRadius;
private float topRightRadius;
private float bottomLeftRadius;
private float bottomRightRadius;
//边框虚线的宽度
float dashWidth = 0;
//边框虚线的间隙
float dashGap = 0;
//字体色
private int textColor = 0;
public ShapeTextView(Context context) {
this(context, null);
}
public ShapeTextView(Context context, @Nullable AttributeSet attrs) {
this(context, attrs, 0);
}
public ShapeTextView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context, attrs);
//默认背景
gradientDrawable = getNeedDrawable(new float[]{topLeftRadius, topLeftRadius, topRightRadius, topRightRadius,
bottomRightRadius, bottomRightRadius, bottomLeftRadius, bottomLeftRadius},
solidColor, strokeWidth, strokeColor, dashWidth, dashGap);
//如果设置了选中时的背景
if (openSelector) {
selectorDrawable = getNeedDrawable(new float[]{topLeftRadius, topLeftRadius, topRightRadius, topRightRadius,
bottomRightRadius, bottomRightRadius, bottomLeftRadius, bottomLeftRadius},
solidTouchColor, strokeWidth, strokeTouchColor, dashWidth, dashGap);
//动态生成Selector
StateListDrawable stateListDrawable = new StateListDrawable();
//是否按下
int pressed = android.R.attr.state_pressed;
stateListDrawable.addState(new int[]{pressed}, selectorDrawable);
stateListDrawable.addState(new int[]{}, gradientDrawable);
setBackground(stateListDrawable);
} else {
setBackground(gradientDrawable);
}
}
/**
* 初始化参数
*
* @param context
* @param attrs
*/
private void init(Context context, AttributeSet attrs) {
TypedArray ta = context.getTheme().obtainStyledAttributes(attrs, R.styleable.ShapeTextView, 0, 0);
openSelector = ta.getBoolean(R.styleable.ShapeTextView_openSelector, false);
solidColor = ta.getInteger(R.styleable.ShapeTextView_solidColor, 0x00000000);
strokeColor = ta.getInteger(R.styleable.ShapeTextView_strokeColor, 0x00000000);
solidTouchColor = ta.getInteger(R.styleable.ShapeTextView_solidTouchColor, 0x00000000);
strokeTouchColor = ta.getInteger(R.styleable.ShapeTextView_strokeTouchColor, 0x00000000);
textTouchColor = ta.getInteger(R.styleable.ShapeTextView_textTouchColor, 0x00000000);
textColor = getCurrentTextColor();
strokeWidth = (int) ta.getDimension(R.styleable.ShapeTextView_strokeWidth, 0);
//四个角单独设置会覆盖radius设置
radius = ta.getDimension(R.styleable.ShapeTextView_radius, 0);
topLeftRadius = ta.getDimension(R.styleable.ShapeTextView_topLeftRadius, radius);
topRightRadius = ta.getDimension(R.styleable.ShapeTextView_topRightRadius, radius);
bottomLeftRadius = ta.getDimension(R.styleable.ShapeTextView_bottomLeftRadius, radius);
bottomRightRadius = ta.getDimension(R.styleable.ShapeTextView_bottomRightRadius, radius);
dashGap = ta.getDimension(R.styleable.ShapeTextView_dashGap, 0);
dashWidth = ta.getDimension(R.styleable.ShapeTextView_dashWidth, 0);
ta.recycle();
}
/**
* @param radius 四个角的半径
* @param colors 渐变的颜色
* @param strokeWidth 边框宽度
* @param strokeColor 边框颜色
* @return
*/
public static GradientDrawable getNeedDrawable(float[] radius, int[] colors, int strokeWidth, int strokeColor) {
//TODO:判断版本是否大于16 项目中默认的都是Linear散射 都是从左到右 都是只有开始颜色和结束颜色
GradientDrawable drawable;
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
drawable = new GradientDrawable();
drawable.setOrientation(GradientDrawable.Orientation.LEFT_RIGHT);
drawable.setColors(colors);
} else {
drawable = new GradientDrawable(GradientDrawable.Orientation.LEFT_RIGHT, colors);
}
drawable.setCornerRadii(radius);
drawable.setStroke(strokeWidth, strokeColor);
drawable.setGradientType(GradientDrawable.LINEAR_GRADIENT);
return drawable;
}
/**
* @param radius 四个角的半径
* @param bgColor 背景颜色
* @param strokeWidth 边框宽度
* @param strokeColor 边框颜色
* @return
*/
public static GradientDrawable getNeedDrawable(float[] radius, int bgColor, int strokeWidth, int strokeColor) {
GradientDrawable drawable = new GradientDrawable();
drawable.setShape(GradientDrawable.RECTANGLE);
drawable.setCornerRadii(radius);
drawable.setStroke(strokeWidth, strokeColor);
drawable.setColor(bgColor);
return drawable;
}
/**
* @param radius 四个角的半径
* @param bgColor 背景颜色
* @param strokeWidth 边框宽度
* @param strokeColor 边框颜色
* @param dashWidth 虚线边框宽度
* @param dashGap 虚线边框间隙
* @return
*/
public static GradientDrawable getNeedDrawable(float[] radius, int bgColor, int strokeWidth, int strokeColor, float dashWidth, float dashGap) {
GradientDrawable drawable = new GradientDrawable();
drawable.setShape(GradientDrawable.RECTANGLE);
drawable.setCornerRadii(radius);
drawable.setStroke(strokeWidth, strokeColor, dashWidth, dashGap);
drawable.setColor(bgColor);
return drawable;
}
}
使用示例
效果如下图：
image.png
踩坑
如果需要selector选择器的效果，需要在xml中设置app:openSelector="true"
然后要给View设置监听事件
text1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
}
});
总结
这里我们使用了Java代码来创建Drawable，可以把常用方法提取到工具类中。
日常开发中也有其他类似的需要定义CheckBox、RadioButton等背景的，也可以参考这种做法。
参考：
Drawable子类之——StateListDrawable （选择器）