tikzpicture 中连接线条时出现间隙

Question

我正在尝试绘制框图，但遇到了一个问题，因为直角线没有与其他线连接（存在间隙）

代码

\documentclass[borders=5cm,circuitikz]{standalone}
\usepackage{pgf,tikz}
\usetikzlibrary{arrows}
\usetikzlibrary{shapes,arrows}
\begin{document}
% Definition of blocks:
\tikzset{%
  block/.style    = {draw, thick, rectangle,
  anchor=west,
  rounded corners,align=center},
  sum/.style      = {draw, circle, node distance = 2cm}, % Adder
  input/.style    = {coordinate}, % Input
  output/.style   = {coordinate} % Output
}
 \tikzset{merge/.style={
        draw,
        isosceles triangle,
        isosceles triangle apex angle=60,
        shape border rotate=0
    },}

\begin{tikzpicture}[auto, thick, node distance=2cm, >=triangle 45]
\draw
    % Drawing the blocks of first filter :
    node at (0,0)[input, name=input1,right=-1cm]{}
    node [block,right of=input1, minimum height = 3.5em,
    minimum width = 4.5em,  text width=4.5em,  node distance=2.5cm](block1) {X}
        node [merge,right of=block1 , node distance=4.5cm](tri1) {} 
        node at (tri1)[right=1.5mm]{\small \textopenbullet}     
                node [block,below of=tri1, minimum height = 2em,
    minimum width = 2em,node distance=1.5cm](block4) {y};
\draw[->](block1) -- node {}(tri1);
\node at (block4)[left=1cm](test33){};
\node at (tri1)[left=1cm](test55){};
\draw[-](test55)-- (test33) -- (block4); 
  

\end{tikzpicture}
\end{document}

Answer 1

\documentclass[borders=5cm,circuitikz]{standalone}
\usepackage{pgf,tikz}
\usetikzlibrary{arrows, positioning, calc}
\usetikzlibrary{shapes,arrows}
\begin{document}
% Definition of blocks:
\tikzset{%
  block/.style    = {draw, thick, rectangle, anchor=west, rounded corners,align=center},
  sum/.style      = {draw, circle, node distance = 2cm}, % Adder
  input/.style    = {coordinate}, % Input
  output/.style   = {coordinate} % Output
}
 \tikzset{merge/.style={
        draw,
        isosceles triangle,
        isosceles triangle apex angle=60,
        shape border rotate=0
    },}

\begin{tikzpicture}[auto, thick, node distance=2cm, >=triangle 45]
\draw
    % Drawing the blocks of first filter :
    node    at (0,0)        [input, 
                            name=input1,]
                            {}
    node                    [
                            block,
                            right=of input1, 
                            minimum height = 3.5em,
                            minimum width = 4.5em,  
                            text width=4.5em,  
                            node distance=2.5cm]
                            (block1) {X}
   node                     [merge,
                            right=of block1 , 
                            node distance=4.5cm]
                            (tri1) {} 
   node     at($(tri1.east)+(1pt,0pt)$)
                            {\small \textopenbullet}     
   node                     [block,
                            below of=tri1, 
                            minimum height = 2em,
                            minimum width = 2em,
                            node distance=1.5cm]
                            (block4) {y};
\draw[->]   (block1)                    -- (tri1);
\draw[-]    ($(block1)!0.5!(tri1)$)     |- (block4); 

\end{tikzpicture}
\end{document}

Answer 2

您用来nodes放置辅助位置。由于绘制时节点具有默认大小(test55)-- (test33) -- (block4)，因此线条会在其边界处停止。查看绘制这些节点的以下代码：

\documentclass[borders=5cm,circuitikz]{standalone}
\usepackage{pgf,tikz}
\usetikzlibrary{arrows}
\usetikzlibrary{shapes,arrows}
\begin{document}
% Definition of blocks:
\tikzset{%
  block/.style    = {draw, thick, rectangle,
  anchor=west,
  rounded corners,align=center},
  sum/.style      = {draw, circle, node distance = 2cm}, % Adder
  input/.style    = {coordinate}, % Input
  output/.style   = {coordinate} % Output
}
 \tikzset{merge/.style={
        draw,
        isosceles triangle,
        isosceles triangle apex angle=60,
        shape border rotate=0
    },}

\begin{tikzpicture}[auto, thick, node distance=2cm, >=triangle 45]
\draw
    % Drawing the blocks of first filter :
    node at (0,0)[input, name=input1,right=-1cm]{}
    node [block,right of=input1, minimum height = 3.5em,
    minimum width = 4.5em,  text width=4.5em,  node distance=2.5cm](block1) {X}
        node [merge,right of=block1 , node distance=4.5cm](tri1) {} 
        node at (tri1)[right=1.5mm]{\small \textopenbullet}     
                node [block,below of=tri1, minimum height = 2em,
    minimum width = 2em,node distance=1.5cm](block4) {y};
\draw[->](block1) -- (tri1);
\node[draw, red] at (block4)[left=1cm](test33){};
\node[draw, red] at (tri1)[left=1cm](test55){};
\draw[-](test55)-- (test33) -- (block4); 
  

\end{tikzpicture}
\end{document}

您有两种选择，使用\draw (test55.center)-- (test33.center) -- (block4);或将它们定义为coordinates像点一样的节点，没有任何默认大小：

\coordinate (test33) at ([xshift=-1cm]tri1.west);
\draw[-](test33) |- (block4);