Android消息提示框Toast

Android消息提示框Toast

Toast是Android中一種簡易的消息提示框。和Dialog不一樣的是，Toast是沒有焦點的，toast提示框不能被用戶點擊，而且Toast顯示的時間有限，toast會根據用戶設置的顯示時間後自動消失。

創建Toast的方法總共有2種：

1.Toast.makeText(Context context, (CharSequence text)/( int resId), int duration)

參數：context是指上下文對象，通常是當前的Activity,text是指自己寫的消息內容，resId指顯示內容引用Resource的那條數據，duration指Toast的顯示時間，Toast默認有LENGTH_SHORT和LENGTH_LONG兩常量，分別表示時間長和短，也可以自定義時間，如：5000表示顯示5秒。用此方法獲得Toast對象之後調用.show()方法即可顯示消息。

2.自定義Toast,通過Toast toast = new Toast(Context context)獲得Toast對象，調用.show()方法即可顯示消息。

toast.setDuration(duration)設置顯示時間，

toast.setGravity(gravity, xOffset, yOffset)設置顯示位置，三個參數分別表示(起點位置,水平位移,垂直位移)，

toast.setMargin(float horizontalMargin, float verticalMargin)以橫向和縱向的百分比設置顯示位置，參數均爲float類型(水平位移正右負左，豎直位移正上負下)，

toast.setText(text)設置消息內容，

toast.setView(view)設置Toast顯示的視圖組件。

實例：

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:gravity="center"
    android:orientation="vertical"
    android:padding="10dp" >

    <Button
        android:id="@+id/simpleToast"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="默認" >
    </Button>

    <Button
        android:id="@+id/simpleToastWithCustomPosition"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="自定義顯示位置" >
    </Button>

    <Button
        android:id="@+id/imageToast"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="帶圖片" >
    </Button>

    <Button
        android:id="@+id/customToast"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="完全自定義" >
    </Button>

    <Button
        android:id="@+id/runToastFromOtherThread"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="其他線程" >
    </Button>

</LinearLayout>

custom.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/toastLayout"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical" >

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="1dp"
        android:background="#333399"
        android:gravity="center"
        android:text="ToastTitle"
        android:textColor="#ffffff" />

    <LinearLayout
        android:id="@+id/toastContent"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="1dp"
        android:layout_marginLeft="1dp"
        android:layout_marginRight="1dp"
        android:background="#3366ff"
        android:orientation="vertical"
        android:padding="15dp" >

        <ImageView
            android:id="@+id/customImageToast"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center" />

        <TextView
            android:id="@+id/customTextToast"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:paddingLeft="10dp"
            android:paddingRight="10dp" />
    </LinearLayout>

</LinearLayout>

MainActivity.java

public class MainActivity extends Activity implements OnClickListener {

	private Button simpleToastBtn, simpleToastWithCustomPositionBtn,
			imageToastBtn, customToastBtn, runToastFromOtherThreadBtn;
	Handler handler = new Handler();

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		simpleToastBtn = (Button) findViewById(R.id.simpleToast);
		simpleToastWithCustomPositionBtn = (Button) findViewById(R.id.simpleToastWithCustomPosition);
		imageToastBtn = (Button) findViewById(R.id.imageToast);
		customToastBtn = (Button) findViewById(R.id.customToast);
		runToastFromOtherThreadBtn = (Button) findViewById(R.id.runToastFromOtherThread);

		simpleToastBtn.setOnClickListener(this);
		simpleToastWithCustomPositionBtn.setOnClickListener(this);
		imageToastBtn.setOnClickListener(this);
		customToastBtn.setOnClickListener(this);
		runToastFromOtherThreadBtn.setOnClickListener(this);
	}

	@Override
	public void onClick(View v) {
		Toast toast = null;
		switch (v.getId()) {
		case R.id.simpleToast:
			Toast.makeText(MainActivity.this, "默認Toast樣式", Toast.LENGTH_LONG)
					.show();
			break;

		case R.id.simpleToastWithCustomPosition:
			toast = Toast.makeText(MainActivity.this, "自定義位置Toast",
					Toast.LENGTH_LONG);
			toast.setGravity(Gravity.CENTER, 0, 0);
			toast.show();
			break;

		case R.id.imageToast:
			toast = Toast.makeText(MainActivity.this, "帶圖片的Toast",
					Toast.LENGTH_LONG);
			LinearLayout layout = (LinearLayout) toast.getView();
			ImageView image = new ImageView(MainActivity.this);
			image.setImageResource(R.drawable.ic_launcher);
			layout.addView(image, 0);
			toast.show();
			break;

		case R.id.customToast:
			LayoutInflater inflater = getLayoutInflater();
			View view = inflater.inflate(R.layout.custom, null);

			ImageView customImage = (ImageView) view
					.findViewById(R.id.customImageToast);
			TextView customText = (TextView) view
					.findViewById(R.id.customTextToast);
			customImage.setImageResource(R.drawable.ic_launcher);
			customText.setText("完全自定義Toast");

			toast = new Toast(MainActivity.this);
			toast.setGravity(Gravity.RIGHT | Gravity.TOP, 30, 30);
			toast.setDuration(Toast.LENGTH_LONG);
			toast.setView(view);
			toast.show();
			break;

		case R.id.runToastFromOtherThread:
			new Thread(new Runnable() {
				public void run() {
					showToast();
				}
			}).start();
			break;
		}
	}

	public void showToast() {
		handler.post(new Runnable() {
			@Override
			public void run() {
				Toast.makeText(MainActivity.this, "我來自其他線程", Toast.LENGTH_LONG)
						.show();
			}
		});
	}
}