• 获取光标位置

      int index = editText.getSelectionStart();  

• 在光标处插入字符

      int index = editText.getSelectionStart();  
      Editable editable = editText.getText();  
      editable.insert(index, "aaaa");  

• 删除光标前字符

      int index = editText.getSelectionStart();  
      Editable editable = editText.getText();  
      editable.delete(index-1, index);  

• 选中文字

      //选中所有字符
      mEditText.setSelection(0, str.length());

• 点击EditText获取焦点显示光标且不弹出软键盘

 
        editText.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                editText.requestFocus();
                int inType = editText.getInputType();
                editText.setInputType(InputType.TYPE_NULL);
                editText.onTouchEvent(event);
                editText.setInputType(inType);
                editText.setSelection(editText.getText().length());
                return true;
            }
        });

• 处理软键盘回删按钮backSpace时不会回调OnKeyListener

自定义一个View继承自EditText，重写其onCreateInputConnection（EditInfo）方法：

public class DeletableEditText extends EditText {

    public DeletableEditText(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

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

    public DeletableEditText(Context context) {
        super(context);
    }

    @Override
    public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
        return new DeleteInputConnection(super.onCreateInputConnection(outAttrs),
                true);
    }

    private class DeleteInputConnection extends InputConnectionWrapper {

        public DeleteInputConnection(InputConnection target, boolean mutable) {
            super(target, mutable);
        }

        @Override
        public boolean sendKeyEvent(KeyEvent event) {
            return super.sendKeyEvent(event);
        }
        @Override
        public boolean deleteSurroundingText(int beforeLength, int afterLength) {
            //在删除时，输入框无内容，或者删除以后输入框无内容
            if (beforeLength == 1 && afterLength == 0) {
                return sendKeyEvent(new KeyEvent(KeyEvent.ACTION_DOWN,
                        KeyEvent.KEYCODE_DEL))
                        && sendKeyEvent(new KeyEvent(KeyEvent.ACTION_UP,
                        KeyEvent.KEYCODE_DEL));
            }

            return super.deleteSurroundingText(beforeLength, afterLength);
        }

    }
}