从在UI线程中运行代码的角度来看，以下两者之间有什么区别:
MainActivity.this.runOnUiThread(new Runnable() {
public void run() {
Log.d("UI thread", "I am the UI thread");
}
});
or
MainActivity.this.myView.post(new Runnable() {
public void run() {
Log.d("UI thread", "I am the UI thread");
}
});
and
private class BackgroundTask extends AsyncTask<String, Void, Bitmap> {
protected void onPostExecute(Bitmap result) {
Log.d("UI thread", "I am the UI thread");
}
}
当前回答
使用Handler还有第四种方法
new Handler().post(new Runnable() {
@Override
public void run() {
// Code here will run in UI thread
}
});
其他回答
芬兰湾的科特林版:
Handler(Looper.getMainLooper()).post {
Toast.makeText(context, "Running on UI(Main) thread.", Toast.LENGTH_LONG).show()
}
或者如果你正在使用Kotlin协程: 在协程范围内添加:
withContext(Dispatchers.Main) {
Toast.makeText(context, "Running on UI(Main) thread.", Toast.LENGTH_LONG).show()
}
使用Handler还有第四种方法
new Handler().post(new Runnable() {
@Override
public void run() {
// Code here will run in UI thread
}
});
我喜欢HPP评论中的那个，它可以在任何地方使用，没有任何参数:
new Handler(Looper.getMainLooper()).post(new Runnable() {
@Override
public void run() {
Log.d("UI thread", "I am the UI thread");
}
});
如果你需要在碎片中使用，你应该使用
private Context context;
@Override
public void onAttach(Context context) {
super.onAttach(context);
this.context = context;
}
((MainActivity)context).runOnUiThread(new Runnable() {
public void run() {
Log.d("UI thread", "I am the UI thread");
}
});
而不是
getActivity().runOnUiThread(new Runnable() {
public void run() {
Log.d("UI thread", "I am the UI thread");
}
});
因为在某些情况下会有空指针异常，如分页片段
使用处理程序
new Handler(Looper.getMainLooper()).post(new Runnable() {
@Override
public void run() {
// Code here will run in UI thread
}
});
