如何以编程方式在约束布局中移动视图(按钮)? [英] How to move a view (button) programmatically in a constraint layout?

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问题描述

我正在尝试创建一个简单的时间表(我是初学者).我为7天24小时的时间表创建了一个基本布局，我的想法是通过编程方式插入按钮，并通过操纵按钮的位置和宽度在正确的时间和持续时间上覆盖时间表，以便在单击时显示它们任务保存在下面的文本视图中，如下所示:

I'm trying to create a simple timetable, (I'm a beginner). I have created a basic layout for the timetable with 7 days and 24 hours, and my idea was to insert buttons programmatically, overlaying the timetable for the correct time and duration by manipulating the position and width of the buttons, so that when clicked they display the task saved in the textview below as such:

我知道如何创建按钮，但是经过数小时的寻找可行的方法以将其大小和位置更改为所需值的方法失败后，我还是在这里寻求帮助.

I know how to create the buttons but after hours of searching for a working method to change their size and location to the desired values with no success I turn here for help.

作为测试，我制作了一个新的空项目，在设计视图中具有一个预制的约束视图，并尝试在其中放置一个按钮并将其移动.这是代码:

As a test I made a new empty project with one premade constraint view in the design view and tried to place a single button within it and move it. Here is the code:


import androidx.appcompat.app.AppCompatActivity;
import androidx.constraintlayout.widget.ConstraintLayout;
import androidx.constraintlayout.widget.ConstraintSet;

import android.os.Bundle;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ConstraintLayout constraintLayout01 = (ConstraintLayout)findViewById(R.id.constraintLayout01); //a constraint layout pre-made in design view

        Button btn = new Button(this);
        btn.setLayoutParams(new ConstraintLayout.LayoutParams(ConstraintLayout.LayoutParams.WRAP_CONTENT, ConstraintLayout.LayoutParams.WRAP_CONTENT));
        constraintLayout01.addView(btn);

        int x = 100;
        int y = 5;
        ConstraintSet set = new ConstraintSet();
        set.connect(btn.getId(), ConstraintSet.LEFT, constraintLayout01.getId(), ConstraintSet.LEFT, x);
        set.connect(btn.getId(), ConstraintSet.TOP, constraintLayout01.getId(), ConstraintSet.TOP, y);
    }
}

该按钮出现在约束视图中，但是无论我如何更改x和y，都不会改变位置.我究竟做错了什么?另外，如何更改尺寸?

The button appears within the constraint view but no matter how I change x and y nothing ever changes location. What am I doing wrong? Also how can I change the size?

根据要求向xml添加了一个按钮:

Added a button to xml as requested: 

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/RootLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/constraintLayout01"
        android:layout_width="390dp"
        android:layout_height="645dp"
        android:layout_marginStart="28dp"
        android:layout_marginTop="16dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <Button
            android:id="@+id/button2"
            android:layout_width="38dp"
            android:layout_height="41dp"
            android:layout_marginStart="100dp"
            android:layout_marginTop="100dp"
            android:text=""
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    </androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

edit2:

logcat:

2020-03-23 10:24:56.111 10888-10888/? E/.example.test0: Unknown bits set in runtime_flags: 0x8000
2020-03-23 10:24:56.201 10888-10888/com.example.test02 I/Perf: Connecting to perf service.
2020-03-23 10:24:56.210 10888-10918/com.example.test02 E/Perf: Fail to get file list com.example.test02
2020-03-23 10:24:56.210 10888-10918/com.example.test02 E/Perf: getFolderSize() : Exception_1 = java.lang.NullPointerException: Attempt to get length of null array
2020-03-23 10:24:56.307 10888-10888/com.example.test02 W/.example.test0: Accessing hidden method Landroid/view/View;->computeFitSystemWindows(Landroid/graphics/Rect;Landroid/graphics/Rect;)Z (greylist, reflection, allowed)
2020-03-23 10:24:56.308 10888-10888/com.example.test02 W/.example.test0: Accessing hidden method Landroid/view/ViewGroup;->makeOptionalFitsSystemWindows()V (greylist, reflection, allowed)
2020-03-23 10:24:56.346 10888-10888/com.example.test02 D/AndroidRuntime: Shutting down VM
2020-03-23 10:24:56.347 10888-10888/com.example.test02 E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.test02, PID: 10888
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.test02/com.example.test02.MainActivity}: java.lang.RuntimeException: All children of ConstraintLayout must have ids to use ConstraintSet
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3271)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3410)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2017)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7397)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:935)
     Caused by: java.lang.RuntimeException: All children of ConstraintLayout must have ids to use ConstraintSet
        at androidx.constraintlayout.widget.ConstraintSet.clone(ConstraintSet.java:713)
        at com.example.test02.MainActivity.onCreate(MainActivity.java:29)
        at android.app.Activity.performCreate(Activity.java:7802)
        at android.app.Activity.performCreate(Activity.java:7791)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1307)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3246)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3410) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2017) 
        at android.os.Handler.dispatchMessage(Handler.java:107) 
        at android.os.Looper.loop(Looper.java:214) 
        at android.app.ActivityThread.main(ActivityThread.java:7397) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:935) 

推荐答案

这些行丢失了

    btn.setId(View.generateViewId());
    set.clone(constraintLayout);
    set.applyTo(constraintLayout);

这是输出的有效解决方案.

Here is the working solution with the output.

public class Main_One extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_one);
        ConstraintLayout constraintLayout = (ConstraintLayout)findViewById(R.id.connstraint_layout); //a constraint layout pre-made in design view
        Button btn = new Button(this);
        btn.setText("StackFlow");
        btn.setLayoutParams(new ConstraintLayout.LayoutParams(ConstraintLayout.LayoutParams.WRAP_CONTENT, ConstraintLayout.LayoutParams.WRAP_CONTENT));
        btn.setId(View.generateViewId());
        constraintLayout.addView(btn);
        int x = 100;
        int y = 505;
        ConstraintSet set = new ConstraintSet();
        set.clone(constraintLayout);
        set.connect(btn.getId(), ConstraintSet.LEFT, constraintLayout.getId(), ConstraintSet.LEFT, x);
        set.connect(btn.getId(), ConstraintSet.TOP, constraintLayout.getId(), ConstraintSet.TOP, y);
        set.applyTo(constraintLayout);
}

    }

XML 

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

   <androidx.constraintlayout.widget.ConstraintLayout
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:id="@+id/connstraint_layout">

   </androidx.constraintlayout.widget.ConstraintLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

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