前言

为了提升用户体验，很多时候我们都需要在输入框后面添加“一键清空”按钮，比如输入账号密码时。实现起来也很简单，可以直接在EditText外面包裹一层FrameLayout，然后添加一个删除按钮。但是这样子逻辑稍微复杂，如果很多地方用的话还是很麻烦的。所以今天我们来实现一个带删除按钮的EditText，简化我们的开发过程。

截图

效果图

关键代码

public class ClearableEditText extends AppCompatEditText {
    private static final int DRAWABLE_LEFT = 0;
    private static final int DRAWABLE_TOP = 1;
    private static final int DRAWABLE_RIGHT = 2;
    private static final int DRAWABLE_BOTTOM = 3;
    private Drawable mClearDrawable;

    public ClearableEditText(Context context) {
        super(context);
        init();
    }

    public ClearableEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

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

    private void init() {
        mClearDrawable = getResources().getDrawable(R.drawable.ic_edit_text_clear);
    }

    @Override
    protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
        super.onTextChanged(text, start, lengthBefore, lengthAfter);
        setClearIconVisible(hasFocus() && text.length() > 0);
    }

    @Override
    protected void onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect) {
        super.onFocusChanged(focused, direction, previouslyFocusedRect);
        setClearIconVisible(focused && length() > 0);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_UP:
                Drawable drawable = getCompoundDrawables()[DRAWABLE_RIGHT];
                if (drawable != null && event.getX() <= (getWidth() - getPaddingRight())
                        && event.getX() >= (getWidth() - getPaddingRight() - drawable.getBounds().width())) {
                    setText("");
                }
                break;
        }
        return super.onTouchEvent(event);
    }

    private void setClearIconVisible(boolean visible) {
        setCompoundDrawablesWithIntrinsicBounds(getCompoundDrawables()[DRAWABLE_LEFT], getCompoundDrawables()[DRAWABLE_TOP],
                visible ? mClearDrawable : null, getCompoundDrawables()[DRAWABLE_BOTTOM]);
    }
}

使用

直接将layout中的EditText改为$your package name$.ClearableEditText即可。
如果没有依赖v7包需将其继承的AppCompatEditText改为普通的EditText。

源码下载