Raymond Yang

Introduction

Recently I am studying Android again, so many amazing changes since 2 years ago, it’s worth stepping forward.

This post will introduce how to define your own style, how to design layout and how to use multiThread to update Activity components.

Define your own style

We can define our own style and use them to decorate our layout. To do this, first go to the styles.xml, it locates at

/res/values/styles.xml

Then we can start define our own style

<style name="TextStyle" parent="@android:style/TextAppearance">
        <item name="android:layout_width">wrap_content</item>
        <item name="android:layout_height">wrap_content</item>
        <item name="android:layout_centerHorizontal">true</item>
        <item name="android:layout_centerVertical">true</item>
</style>

Remember we have to inherit the parent

parent="@android:style/TextAppearance"

in the base class. The inheritance can be multi levels, you can start the magic now!

Design Layout

There are so many tags in android when starting layout design. Here I will list some useful tags when design your own layout.

align clusters

enables you to use the relative layout greatly, you can explore it by yourself. For example,

android:layout_alignBaselin

Make the target in the same line with the source

Multi Thread

When we want to refresh or update some components in the activity periodically (at a corresponding fast and automatic way, we need to use a thread to do this). Because activity is used as a thread, it cannot handle to much work, use another thread to handle extra big works seems the best way ( also applied when download or update picture)

btnStart.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Thread t = new Thread() {
            @Override
            public void run() {
                try {
                    while (!isInterrupted()) {
                        Thread.sleep(3000);
                        runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                simulate(i);
                                i++;
                            }
                        });
                    }
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        };
        t.start();
    }
});

Add the previous code in the onCreate which start a new Thread to do the extera hard work. Define what you want the system do in the run function.

For complete code, you can refer my github.