Android可扩展文本视图,"查看更多"按钮显示在3行后的中心

Question

我想在文本视图中显示描述,如果描述超过3行我想显示一个查看更多按钮,用于扩展文本视图以及完整描述(或带有完整描述的对话框)

我已经提到了一些链接
1)我如何实现像Google Play一样的可折叠视图？

上面的解决方案在文本视图的第三行末尾有一个类似于图像视图的箭头,但是如果描述跨越3行,我想要一个显示在文本视图下方的按钮.

2)在3行之后的textview末尾添加"查看更多"

以上解决方案有"查看更多"未对齐(第3行"查看"和第4行"更多")

我正在寻找这样的东西.

Answer 1

这就是我如何实现所需的输出,

我想要扩展的MytextView是:tvDescription我有一个名称更多的按钮:btnSeeMore

要检查textview是否有超过4行,我有一个监听器,如下所示,

tvDescription.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
                @Override
                public void onGlobalLayout() {
                    if(expandable) {
                        expandable = false;
                        if (tvDescription.getLineCount() > 4) {
                            btnSeeMore.setVisibility(View.VISIBLE);
                            ObjectAnimator animation = ObjectAnimator.ofInt(tvDescription, "maxLines", 4);
                            animation.setDuration(0).start();
                        }
                    }
                }
            });

我保留了一个布尔值来检查textview是否已经展开,以便在折叠时不会有任何hickup.

如果textview有四行以上,boolean flag将为true,按钮将可见,因此这是扩展和折叠动画的代码.

btnSeeMore.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {

                if (!expand) {
                    expand = true;
                    ObjectAnimator animation = ObjectAnimator.ofInt(tvDescription, "maxLines", 40);
                    animation.setDuration(100).start();
                    btnSeeMore.setImageDrawable(ContextCompat.getDrawable(getActivity(), R.drawable.ic_collapse));
                } else {
                    expand = false;
                    ObjectAnimator animation = ObjectAnimator.ofInt(tvDescription, "maxLines", 4);
                    animation.setDuration(100).start();
                    btnSeeMore.setImageDrawable(ContextCompat.getDrawable(getActivity(),R.drawable.ic_expand));
                }

            }
        });

评论如下以获取更多信息

Answer 2

实现这一目标的简便方法是。

sample.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:id="@+id/tvSongDes"
        android:layout_marginStart="@dimen/dimen16"
        android:layout_marginEnd="@dimen/dimen16"
        android:layout_marginTop="@dimen/dimen16"
        android:maxLines="3"
        android:text="Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy Dummy dummy "
        android:layout_width="match_parent"
        android:layout_height="wrap_content"

        />

    <Button
        android:id="@+id/btShowmore"
        android:layout_width="wrap_content"
        android:layout_marginStart="@dimen/dimen16"
        android:text="Showmore..."
        android:textAllCaps="false"
        android:textColor="@android:color/holo_blue_light"
        android:background="@android:color/transparent"
        android:layout_height="wrap_content" />
</LinearLayout>

并在您的Activity onCreate中。

 TextView tvSongDes;
    Button btShowmore;
          @Override
            protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_devotional_songs_play);
                tvSongDes=(TextView)findViewById(R.id.tvSongDes);
                btShowmore=(Button)findViewById(R.id.btShowmore);
                btShowmore.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {

               if (btShowmore.getText().toString().equalsIgnoreCase("Showmore..."))
                        {
                            tvSongDes.setMaxLines(Integer.MAX_VALUE);//your TextView
                            btShowmore.setText("Showless");
                        }
                        else
                        {
                            tvSongDes.setMaxLines(3);//your TextView
                            btShowmore.setText("Showmore...");
                        }
                    }
                });

            }

希望对某人有帮助。