Question

我想在Android中创建一个功能齐全的视图，可以根据某些配置在特定的时间段内自行更新。

我从RelativeLayout继承了我的视图，我自动在布局中放置了TextView，然后通过发布处理程序，更新TextView边距以在RelativeLayout中移动文本。

自定义视图的代码是（我删除了不必要的行）：

import android.annotation.SuppressLint
import android.content.Context
import android.os.Handler
import android.util.AttributeSet
import android.widget.RelativeLayout
import android.widget.TextView
import blah.blah.test.R

class MovingText : RelativeLayout, Runnable {


    private val tag = MarqueuWidget::class.java.simpleName
    private lateinit var mTextField: TextView
    private lateinit var refreshHandler: Handler

    constructor(context: Context) : super(context) {
        init()
    }

    constructor(context: Context, attrs: AttributeSet) : super(context, attrs) {
        init()
        extractAttributes(attrs)
    }

    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int)
            : super(context, attrs, defStyleAttr) {
        init()
        extractAttributes(attrs)
    }

    @SuppressLint("ResourceType")
    private fun init() {
        // init helper
        mTextField = TextView(context)
        mTextField.setSingleLine(false)
        mTextField.setBackgroundColor(R.color.colorPrimary)
        val lp = RelativeLayout.LayoutParams(
                RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT)
        mTextField.id = 1
        addView(mTextField, lp)
        refreshHandler = Handler()
        refreshHandler.postDelayed(this, 1000)
    }

    /**
     * Runner for refresh handler
     */
    override fun run() {
            val params = mTextField.layoutParams as LayoutParams
            params.leftMargin += 20
            params.topMargin += 20
            mTextField.layoutParams = params
        refreshHandler.postDelayed(this, 1000)
    }

    @SuppressLint("Recycle")
    private fun extractAttributes(attrs: AttributeSet) {
        if (context == null) {
            return
        }
        val a = context.obtainStyledAttributes(attrs,
                R.styleable.blah_blah_widget_MovingText) ?: return
        // some codes
        repaint()
        a.recycle()
    }

    private fun repaint() {
        // sophisticate text view based on parameters
        mTextField.text = "Test"
    }

    override fun onLayout(changed: Boolean, l: Int, t: Int, r: Int, b: Int) {
        if (!changed) return
        if (childCount != 1 || getChildAt(0) !is TextView) {
            throw RuntimeException("TextChunk must not have any child element.")
        }
        if (getChildAt(0) !is TextView) {
            throw RuntimeException("The child view of this chunk must be a TextView instance.")
        }
        super.onLayout(changed, l, t, r, b)
    }

}

尽管相对布局参数（marginTop和marginLeft）随时间变化，但文本不会在视图内移动。有什么问题？

此代码对我有用：

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.os.Handler
import android.widget.RelativeLayout
import android.widget.TextView
import butterknife.ButterKnife

class TestActivity : AppCompatActivity(), Runnable {

    override fun run() {
        handler.postDelayed(this, 100)
        var txt = findViewById<TextView>(R.id.textView1)
        val params = txt.layoutParams as RelativeLayout.LayoutParams
        params.leftMargin += 20
        params.topMargin += 20
        txt.layoutParams = params
    }

    lateinit var handler: Handler

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_test)
        ButterKnife.bind(this)
        handler = Handler()
        handler.postDelayed(this, 1000)
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:id="@+id/textView1"
            android:layout_width="800px"
            android:layout_height="wrap_content"
            android:layout_alignParentStart="false"
            android:layout_alignParentTop="false"
            android:layout_marginStart="-20dp"
            android:layout_marginTop="-10dp"
            android:ellipsize="none"
            android:singleLine="true"
            android:text="daskdjasgdasgdhjasd hasfdhfasghdfash gjdfashjfdhas" />
    </RelativeLayout>
</LinearLayout>

Answer 1

通过删除此行解决了问题：

mTextField.setSingleLine(false)

在这种情况下使用scrollView要好得多。我已经切割this good library并解决了问题。

Android的Marque小部件/视图

1 个答案: