Android消息提示框Toast

Android消息提示框Toast

Toast是Android中一种简易的消息提示框。和Dialog不一样的是，Toast是没有焦点的，toast提示框不能被用户点击，而且Toast显示的时间有限，toast会根据用户设置的显示时间后自动消失。

创建Toast的方法总共有2种：

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

参数：context是指上下文对象，通常是当前的Activity,text是指自己写的消息内容，resId指显示内容引用Resource的那条数据，duration指Toast的显示时间，Toast默认有LENGTH_SHORT和LENGTH_LONG两常量，分别表示时间长和短，也可以自定义时间，如：5000表示显示5秒。用此方法获得Toast对象之后调用.show()方法即可显示消息。

2.自定义Toast,通过Toast toast = new Toast(Context context)获得Toast对象，调用.show()方法即可显示消息。

toast.setDuration(duration)设置显示时间，

toast.setGravity(gravity, xOffset, yOffset)设置显示位置，三个参数分别表示(起点位置,水平位移,垂直位移)，

toast.setMargin(float horizontalMargin, float verticalMargin)以横向和纵向的百分比设置显示位置，参数均为float类型(水平位移正右负左，竖直位移正上负下)，

toast.setText(text)设置消息内容，

toast.setView(view)设置Toast显示的视图组件。

 

实例：

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="默认" >
    </Button>

    <Button
        android:id="@+id/simpleToastWithCustomPosition"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="自定义显示位置" >
    </Button>

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

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

    <Button
        android:id="@+id/runToastFromOtherThread"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="其他线程" >
    </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, "默认Toast样式", Toast.LENGTH_LONG)
                    .show();
            break;

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

        case R.id.imageToast:
            toast = Toast.makeText(MainActivity.this, "带图片的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("完全自定义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, "我来自其他线程", Toast.LENGTH_LONG)
                        .show();
            }
        });
    }
}